definition of biodiversity essay

Biodiversity 101: Why it matters and how to protect it

• May 21, 2020

The Earth is undergoing a mass extinction that could see up to a million species disappear in the coming decades – and humans are contributing heavily to this.

The numbers are staggering: the population sizes of vertebrate species, which include mammals, reptiles, birds and fish, dropped by around half between 1970 and 2010 . A quarter of mammals, 40 percent of amphibians, and 30 percent of sharks and rays are currently endangered .

During the 20th century, extinction rates were about 100 times higher than they would have been without humans significantly altering most of the planet’s surface .

What does this loss of biodiversity mean for the future of the planet and its inhabitants – and what can we do about it? The first step is understanding the basics, unraveled in easy-to-digest terms here in this explainer:

What is biodiversity?

How is biodiversity measured, what are the benefits of biodiversity, what are the main threats to biodiversity, how can we protect biodiversity.

Coined by biologists in the 1980s as a contraction of biological diversity , the term usually refers to the variety of life on Earth as a whole . The U.N. Convention on Biological Diversity (CBD) breaks it down as follows :

“Biological diversity” means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part.

But the CBD makes it clear that measuring biodiversity is no simple feat:

This includes diversity within species, between species and of ecosystems.

Let’s start with biodiversity between species, or species diversity . Arguably the simplest measure is ‘species richness’ – a count of how many species live in a community.

But species richness does not consider the relative abundance of each species, or its importance to an ecosystem or landscape, or its value to people. As such, biologists have invented diversity indices, such as the Simpson index and the Shannon index , to take these factors into account.

When talking about biodiversity loss, we often focus on losses in species diversity, as it is crucial to maintain the balance of ecosystems, nutritional value of food, and enhance resilience of ecosystems and landscapes to the threats of climate change and other risks like weeds and pests.

Yet genetic diversity – the characteristics of a species’ genetic makeup – is equally important, as it ensures resilience to change and stressors on a more individual level.

Consider the following analogy: in investing, a diversified portfolio minimizes risk and usually provides the most reliable returns. Likewise, genetic diversity protects a species from being wiped out by an external shock like a natural disaster or disease outbreak.

At the largest scale is the concept of ecosystem diversity , which measures how many different ecosystems exist within a geographical area or wider landscape. The more ecosystems exist within a landscape, the more resilient that landscape is, and the more services it has to offer its inhabitants. 

These include wetlands , which contain over 40 percent of the value of the world’s ecosystems ; peatlands , which store a third of the planet’s soil carbon; and lesser-known tropical forests such as monsoon and karst forests , which are among our best natural defenses against climate change.

You might have also heard of ‘biodiversity hotspots.’ These are landscapes with exceptionally high concentrations of biodiversity. 43 percent of bird, mammal, reptile and amphibian species are only found in areas that make up just 2.4 percent of the Earth’s surface .

Healthy and functional ecosystems play a crucial role in sustaining human livelihoods through providing necessities and benefits such as food, water, energy sources and carbon sequestration, known as ‘ecosystem services.’

One study estimates that each year, the goods and services provided by the planet’s ecosystems contribute over USD 100 trillion to the global economy , more than double the world’s gross domestic product (GDP). But much debate remains over how to factor in non-monetary values, such as natural beauty, regulating functions, and providing homes for humans and animals.

Underpinning ecosystem services are genetic diversity and biodiversity. Genetic diversity supports agriculture by building resilience and protecting against environmental stresses such as pests, crop diseases and natural disasters . This provides a source of income and safeguards the food security of much of the world’s poor.

Biodiversity also plays a role in some ‘ nature-based solutions ’ to climate change and problems caused by changes in the environment. These solutions could provide up to a third of the carbon emissions reductions needed to meet the Paris Agreement goals .

Including biodiversity in nature-based solutions, though, must be a conscious choice. Tree planting , for instance, can come in the form of monocultures (planting just a single species in a landscape) or agroforestry, which mixes species of agricultural crops and trees in a single landscape to enhance the sustainability of both.

While each of these cases offers a different set of financial and environmental benefits, most experts will sing the praises of nature-based solutions that take into account biodiversity over those that don’t.

And, let us not forget: the planet’s various ecosystems and landscapes also hold considerable intrinsic value to humans, whether for their recreational opportunities, their cultural importance to Indigenous communities , or their contributions to physical and mental health . Without biodiversity, these values will be lost.

In a seminal report published last year, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) identified five direct drivers of biodiversity loss: changes in land and sea use, overexploitation, climate change, pollution, and invasive species.

These five drivers, it argues , are in turn driven by increasing demand for natural resources, as well as governance structures that prioritize economic growth over conservation and restoration.

Land and sea use

The most widespread form of land-use change has been the expansion of agriculture : according to the IPBES report, over a third of the Earth’s land surface is now used for cropping or livestock, mainly at the expense of forests , wetlands and grasslands.

The tropics , which are home to the highest levels of biodiversity on Earth, are now seeing their ecosystems replaced by cattle ranching in Latin America and plantations in Southeast Asia .

Other key land-use changes include logging, mining and urbanization. Coastal and marine ecosystems have also been significantly affected by activities such as offshore aquaculture, bottom trawling, coastal development and ocean mining .

Overexploitation

The IPBES suggests that fishing has had a larger impact on marine ecosystems than any other human activity: 33 percent of marine fish stocks are currently overfished, and 60 percent are being fished to their sustainable limits. Poaching and hunting , too, are driving many mammals to the brink of extinction.

Climate change

Humans have caused the planet to warm by around 1 degree Celsius since pre-industrial times – and biodiversity is already bearing the brunt of that warming. Climate change is reducing the distribution of many species (the geographical area in which they can survive), including almost half of all endangered mammals.

Changes in the ecological balance can also result in species that can beneficial turning into pests and plagues once their natural enemies are reduced or disappear: think locusts, mosquitos, algae.

Many plants and animals are also experiencing disruptions to their phenology , which refers to seasonal life cycle events such as flowering, migration and hibernation.

Mining, agriculture, industry and other pervasive changes in human’s land-use are contributing to air, water and soil pollution. The IPBES notes that coastal waters contain the highest levels of metals and organic pollutants, such as industrial discharge and fertilizers.

Similarly, marine plastic pollution has increased tenfold since 1980, primarily affecting marine turtles, seabirds and marine mammals, as well as humans indirectly through the food chain.

Invasive species

An invasive alien species is a species that has been introduced to a new location and starts to disrupt its new habitat. These species can threaten native biodiversity by out-competing them for resources, and they’re spreading ever more quickly as international travel and trade expands. A recent study found that one-sixth of the Earth’s land surface is highly vulnerable to invasion , including many biodiversity hotspots.

Humanity’s ecological footprint is about 70 percent larger than the planet can sustain – and in the world’s richest countries, that figure is as much as four or five times larger. Given these huge inequalities in both living standards and ecological impact, residents of industrialized nations can – and should – do their part to preserve biodiversity by helping contribute to more sustainable global systems.

At the individual level, that could include reducing air travel, buying organic , eating less red meat, avoiding fast fashion , and turning your backyard into a carbon sink .

At the international and policy level , we need commitments to restore the Earth’s ecosystems , following the examples set by the Everglades and farmers in the African Sahel .

Indigenous and local communities are deep and rich sources of traditional knowledge of how best to care for increasingly fragile landscapes. Technological innovation is a crucial tool too.

And with biodiversity worth more in monetary terms than the entire global economy , there’s a clear business case to be made for investing in restoring the planet .

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What is biodiversity and why does it matter to us?

The air you breathe, the water you drink and the food you eat all rely on biodiversity, but right now it is in crisis – because of us. What does this mean for our future and can we stop it?

What is biodiversity?

It is the variety of life on Earth, in all its forms and all its interactions. If that sounds bewilderingly broad, that’s because it is. Biodiversity is the most complex feature of our planet and it is the most vital. “Without biodiversity, there is no future for humanity,” says Prof David Macdonald, at Oxford University.

The term was coined in 1985 – a contraction of “biological diversity” – but the huge global biodiversity losses now becoming apparent represent a crisis equalling – or quite possibly surpassing – climate change.

More formally, biodiversity is comprised of several levels, starting with genes, then individual species, then communities of creatures and finally entire ecosystems, such as forests or coral reefs, where life interplays with the physical environment. These myriad interactions have made Earth habitable for billions of years.

A more philosophical way of viewing biodiversity is this: it represents the knowledge learned by evolving species over millions of years about how to survive through the vastly varying environmental conditions Earth has experienced. Seen like that, experts warn, humanity is currently “ burning the library of life ”.

Do animals and bugs really matter to me?

For many people living in towns and cities, wildlife is often something you watch on television. But the reality is that the air you breathe, the water you drink and the food you eat all ultimately rely on biodiversity. Some examples are obvious: without plants there would be no oxygen and without bees to pollinate there would be no fruit or nuts.

Others are less obvious – coral reefs and mangrove swamps provide invaluable protection from cyclones and tsunamis for those living on coasts, while trees can absorb air pollution in urban areas.

Others appear bizarre – tropical tortoises and spider monkeys seemingly have little to do with maintaining a stable climate. But the dense, hardwood trees that are most effective in removing carbon dioxide from the atmosphere rely on their seeds being dispersed by these large fruit-eaters.

When scientists explore each ecosystem, they find countless such interactions, all honed by millions of years of evolution. If undamaged, this produces a finely balanced, healthy system which contributes to a healthy sustainable planet.

The sheer richness of biodiversity also has human benefits. Many new medicines are harvested from nature, such as a fungi that grows on the fur of sloths and can fight cancer. Wild varieties of domesticated animals and crops are also crucial as some will have already solved the challenge of, for example, coping with drought or salty soils.

If money is a measure, the services provided by ecosystems are estimated to be worth trillions of dollars – double the world’s GDP. Biodiversity loss in Europe alone costs the continent about 3% of its GDP, or €450m (£400m), a year.

From an aesthetic point of view, every one of the millions of species is unique, a natural work of art that cannot be recreated once lost. “Each higher organism is richer in information than a Caravaggio painting, a Bach fugue, or any other great work,” wrote Prof Edward O Wilson, often called the “father of biodiversity”, in a seminal paper in 1985 .

Just how diverse is biodiversity?

Mind-bogglingly diverse. The simplest aspect to consider is species. About 1.7 million species of animals, plants and fungi have been recorded, but there are likely to be 8-9 million and possibly up to 100 million. The heartland of biodiversity is the tropics, which teems with species. In 15 hectares (37 acres) of Borneo forest, for example, there are 700 species of tree – the same number as the whole of North America.

Recent work considering diversity at a genetic level has suggested that creatures thought to be a single species could in some cases actually be dozens. Then add in bacteria and viruses, and the number of distinct organisms may well be in the billions. A single spoonful of soil – which ultimately provides 90% of all food – contains 10,000 to 50,000 different types of bacteria.

The concern is that many species are being lost before we are even aware of them, or the role they play in the circle of life.

How bad is it?

Very. The best studied creatures are the ones like us – large mammals. Tiger numbers, for example, have plunged by 97% in the last century. In many places, bigger animals have already been wiped out by humans – think dodos or woolly mammoths.

The extinction rate of species is now thought to be about 1,000 times higher than before humans dominated the planet, which may be even faster than the losses after a giant meteorite wiped out the dinosaurs 65m years ago. The sixth mass extinction in geological history has already begun , according to some scientists.

Lack of data means the “red list ”, produced by the International Union for Conservation of Nature, has only assessed 5% of known species. But for the best known groups it finds many are threatened : 25% of mammals, 41% of amphibians and 13% of birds.

Species extinction provides a clear but narrow window on the destruction of biodiversity – it is the disappearance of the last member of a group that is by definition rare. But new studies are examining the drop in the total number of animals, capturing the plight of the world’s most common creatures.

The results are scary. Billions of individual populations have been lost all over the planet, with the number of animals living on Earth having plunged by half since 1970 . Abandoning the normally sober tone of scientific papers, researchers call the massive loss of wildlife a “biological annihilation” representing a “frightening assault on the foundations of human civilisation”.

What about under the sea?

Humans may lack gills but that has not protected marine life. The situation is no better – and perhaps even less understood – in the two-thirds of the planet covered by oceans. Seafood is the critical source of protein for more than 2.5 billion people but rampant overfishing has caused catches to fall steadily since their peak in 1996 and now more than half the ocean is industrially fished .

What about bugs – don’t cockroaches survive anything?

More than 95% of known species lack a backbone – there are about as many species in the staphylinidae family of beetles alone as there are total vertebrates, such as mammals, fish and birds. Altogether, there are at least a million species of insect and another 300,000 spiders, molluscs and crustaceans .

But the recent revelation that 75% of flying insects were lost in the last 25 years in Germany – and likely elsewhere – indicates the massacre of biodiversity is not sparing creepy crawlies. And insects really matter, not just as pollinators but as predators of pests, decomposers of waste and, crucially, as the base of the many wild food chains that support ecosystems.

“If we lose the insects then everything is going to collapse,” says Prof Dave Goulson of Sussex University, UK. “We are currently on course for ecological Armageddon.”

Even much-loathed parasites are important. One- third could be wiped out by climate change , making them among the most threatened groups on Earth. But scientists warn this could destabilise ecosystems, unleashing unpredictable invasions of surviving parasites into new areas.

What’s destroying biodiversity?

We are, particularly as the human population rises and wild areas are razed to create farmland, housing and industrial sites. The felling of forests is often the first step and 30m hectares - the area of the Britain and Ireland - were lost globally in 2016.

Poaching and unsustainable hunting for food is another major factor. More than 300 mammal species, from chimpanzees to hippos to bats, are being eaten into extinction .

Pollution is a killer too, with orcas and dolphins being seriously harmed by long-lived industrial pollutants . Global trade contributes further harm: amphibians have suffered one of the greatest declines of all animals due to a fungal disease thought to be spread around the world by the pet trade. Global shipping has also spread highly damaging invasive species around the planet, particularly rats.

The hardest hit of all habitats may be rivers and lakes, with freshwater animal populations in these collapsing by 81% since 1970, following huge water extraction for farms and people, plus pollution and dams.

Could the loss of biodiversity be a greater threat to humanity than climate change?

Yes – nothing on Earth is experiencing more dramatic change at the hands of human activity. Changes to the climate are reversible, even if that takes centuries or millennia. But once species become extinct, particularly those unknown to science, there’s no going back.

At the moment, we don’t know how much biodiversity the planet can lose without prompting widespread ecological collapse. But one approach has assessed so-called “ planetary boundaries ”, thresholds in Earth systems that define a “safe operating space for humanity”. Of the nine considered, just biodiversity loss and nitrogen pollution are estimated to have been crossed, unlike CO2 levels, freshwater used and ozone losses.

What can be done?

Giving nature the space and protection it needs is the only answer. Wildlife reserves are the obvious solution, and the world currently protects 15% of land and 7% of the oceans. But some argue that half the land surface must be set aside for nature.

However, the human population is rising and wildlife reserves don’t work if they hinder local people making a living. The poaching crisis for elephants and rhinos in Africa is an extreme example. Making the animals worth more alive than dead is the key, for example by supporting tourism or compensating farmers for livestock killed by wild predators.

But it can lead to tough choices. “Trophy hunting” for big game is anathema for many. But if the shoots are done sustainably – only killing old lions, for example – and the money raised protects a large swath of land, should it be permitted?

We can all help. Most wildlife is destroyed by land being cleared for cattle, soy, palm oil, timber and leather. Most of us consume these products every day, with palm oil being found in many foods and toiletries. Choosing only sustainable options helps, as does eating less meat, particularly beef, which has an outsized environmental hoofprint.

Another approach is to highlight the value of biodiversity by estimating the financial value of the ecosystem services provided as “natural capital”. Sometimes this can lead to real savings. Over the last 20 years, New York has spent $2bn protecting the natural watershed that supplies the city with clean water. It has worked so well that 90% of the water needs no further filtering: building a water treatment plant instead would have cost $10bn.

What’s next?

Locating the tipping point that moves biodiversity loss into ecological collapse is an urgent priority. Biodiversity is vast and research funds are small, but speeding up analysis might help, from automatically identifying creatures using machine learning to real-time DNA sequencing .

There is even an initiative that aims to create an open-source genetic database for all plants, animals and single-cell organisms on the planet. It argues that by creating commercial opportunities – such as self-driving car algorithms inspired by Amazonian ants – it could provide the incentive to preserve Earth’s biodiversity.

However, some researchers say the dire state of biodiversity is already clear enough and that the missing ingredient is political will.

A global treaty, the Convention on Biological Diversity (CBD), has set many targets. Some are likely to be reached, for example protecting 17% of all land and 10% of the oceans by 2020. Others, such as making all fishing sustainable by the same date are not. The 196 nations that are members of the CBD next meet in Egypt in November.

In his 1985 text, Prof E O Wilson, concluded: “This being the only living world we are ever likely to know, let us join to make the most of it.” That call is more urgent than ever.

Further reading

The Biological Diversity Crisis (1985). Edward O Wilson. BioScience (Vol 35)

The Sixth Extinction : An Unnatural History (2014). Elizabeth Kolbert (Bloomsbury)

What Has Nature Ever Done for Us? (2013) Tony Juniper (Profile)

The Economics of Ecosystems and Biodiversity (2010). Pushpam Kumar et al. (Earthscan)

Illustrations: Frances Marriott

• The briefing
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• Endangered species

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Biodiversity Explained: Facts, Myths, and the Race to Protect It

By MJ Altman on January 4, 2023

A baby sloth hangs in a tree at the Bosque da Ciência in Manaus, Brazil. PHOTO: Michael Dantas/United Nations Foundation

As ecosystems and habitats degrade and disappear worldwide, biodiversity — the interconnectedness of all forms of life on our planet — is in jeopardy. In light of a new global agreement to protect our lands, ocean, and waters, explore what biodiversity really means and what it will take to preserve life on Earth.

From microscopic fungi to mega forests, “biodiversity” is the collective term for the variety of life on Earth in all its forms. It is 4.5 billion years of evolution, embodied.

Biodiversity is responsible for our food, our soil, our water, our weather, even the air we breathe. Yet despite being a crucial foundation for our collective future, biodiversity is often lost amid conversations on climate change — until recently.

In December 2022, leaders from nearly 200 nations adopted a landmark UN agreement to reverse nature’s rapid decline before it’s too late. Known as the Kunming-Montreal Global Biodiversity Framework , it calls for protecting 30% of the planet’s land, ocean, and inland waters and includes 23 other targets to help restore and protect ecosystems and endangered species worldwide.

Here are 12 things you should know:

1. Biodiversity is more than just the total number of species on Earth.

“It is actually more complex than that,” Dr. Thomas Lovejoy, the late ecologist, told the United Nations Foundation in 2018. “It’s about the genetic diversity within species, the diversity of habitats, and the large biological units known as biomes.”

This includes the interactions that occur between species within ecosystems – primordial relationships that shape our environment in countless, often unseen ways.

“Without biological diversity, there is no other life on Earth — including our own,” he explained. “Even though we are often oblivious to it, this diversity of life is what provides clean water, oxygen, and all other things that end up being part of our diet, as well as clothing and shelter. It provides a lot of psychological benefits too, which are not much appreciated.”

2. We’re only just beginning to understand biodiversity’s influence and importance in our lives.

Earth’s many ecosystems rely on a delicate, complicated, and fascinating tangle of life that, in many ways, remains a mystery. In fact, the term “biological diversity” wasn’t introduced to the scientific community until 1980 in a research paper on species loss by Dr. Lovejoy. Scientists still haven’t identified all forms of life on the planet. New species are discovered every year.

A harbor seal swims through kelp off the coast of Southern California's Channel Islands. Seals are among the thousands of species that rely on kelp forests for food and shelter. PHOTO: Shutterstock/Joe Belanger

Take kelp, for example. These undersea forests provide sustenance and shelter for marine species like chinook salmon, which, in turn, serve as a staple food for orcas. And kelp also absorb excess carbon dioxide, which can help mitigate climate change.

3. The planet’s biodiversity holds enormous, untapped potential for medical and scientific breakthroughs.

Lovejoy described each species on the planet as a unique set of solutions for a particular set of biological problems. “Whoever would have thought a bacterium from a Yellowstone hot spring would revolutionize forensic and diagnostic medicine, make the human genome project possible, and confer benefits in the trillion-dollar range?” he wrote as a Senior Fellow at the United Nations Foundation, citing a previously unknown and seemingly inconsequential microbe discovered in 1966 that revolutionized genetic testing and immunization development, including the COVID-19 vaccine.

A flowering plant grows from a tree in the Amazon Rainforest, near the research station known as Camp 41 north of Manaus, Brazil. PHOTO: Michael Dantas/United Nations Foundation

Today, one-fourth of all modern medicines are derived from tropical plants, and 70% of all cancer drugs are natural or bio-inspired products. In the past decade, researchers in Nova Scotia found a soil fungus that can disarm antibiotic-resistant bacteria — a discovery that could transform the fields of medicine and agriculture. The possibilities for discovery and innovation are monumental.

4. Climate change and biodiversity are interconnected.

Climate change is causing biodiversity loss, and biodiversity loss is causing climate change. Here’s how: Destroying and degrading ecosystems releases more carbon dioxide into the atmosphere than burning fossil fuels.

Meanwhile, the consequences of burning fossil fuels — rising global temperatures, an increase in wildfires, and ocean acidification, to name a few — are threatening habitats and wildlife alike. In late 2019 and early 2020, for example, more than 60,000 koalas were killed by wildfires in Australia so massive that nearly 3 billion animals died or were displaced as a result. Earlier this year, the Australian government officially listed koalas as an endangered species.

At COP 27 last year, world leaders reached a historic agreement to create a “loss and damage” fund to support communities that are already feeling climate change’s disastrous impact, including biodiversity loss and its impact on livelihoods.

More than 60,000 koalas were killed by wildfires in Australia in late 2019 and early 2020. Increased wildfires and subsequent habitat loss are just one of the consequences of climate change. PHOTO: Patrick Kavanagh

5. Biodiversity can help us adapt to climate change.

The UN considers biodiversity our strongest natural defense against climate change. Land and ocean ecosystems currently absorb 60% of human-caused emissions , and they are the planet’s only way of storing massive amounts of carbon dioxide. Coastal wetlands, for example, protect against storm surges and flooding during extreme weather while also storing carbon dioxide and creating oxygen.

According to a joint estimate by the UN Development Programme and the Government of Papua New Guinea, every dollar invested in environmental protection generates more than $2,500 in so-called ecosystem services — water regulation, coastal protection, carbon storage, and other invisible functions that nature provides. It’s one of the reasons that Papua New Guinea launched the first-ever national, independent Biodiversity and Climate Fund to protect its status as one of just 17 “megadiverse” countries.

6. Less biodiversity means a higher risk of disease.

For decades, the scientific community has warned that biodiversity loss increases the spread of infectious disease . Why? Because extinction upsets the ecosystem in unpredictable ways, and the destruction of natural habitats increases interaction between humans and wildlife. Biodiversity essentially acts as a barrier between humans and animal-borne disease.

Species that tend to survive logging, farming, mining, wildlife trade and consumption, and other human activities behind widespread biodiversity loss are often “vectors of disease” like mice and mosquitoes, which host pathogens that are able to make the jump to humans. It’s one of the reasons why cases of Lyme disease in the northeast United States have spiked in recent decades: With fewer mammals to prey on, ticks are increasingly seeking out people. In fact, roughly 75% of emerging infectious diseases are zoonotic .

It’s also why researchers like Dr. Alessandra Nava and her team of virus hunters at Brazil’s Fiocruz Amazônia are tracking the spread of disease in bats, monkeys, and rodents in the world’s largest rainforest. Their goal is to stay a step ahead of future pandemics by better understanding the pathogens contained within the jungle’s creatures before they come in contact with humans — encounters that become more likely as the human footprint expands.

A golden-backed squirrel monkey at the Bosque da Ciência, a rainforest park in Manaus, Brazil. PHOTO: Michael Dantas/United Nations Foundation

7. Biodiversity on land depends on biodiversity in water.

Maintaining the ocean’s ecological balance is crucial for protecting biodiversity on land, as well as maintaining our ability to feed future generations. The ocean plays a vital role in regulating the planet’s weather and water and the air we breathe. It is also the planet’s largest source of protein , feeding more than 3 billion people every day who rely on fish as a staple food.

Yet the ocean remains a vastly unexplored ecological frontier. While scientists have identified 200,000 marine species , the actual number is estimated to be in the millions. Unsustainable fishing practices, pollution, climate change, and habitat destruction are threatening creatures that may vanish before we even knew they existed.

8. Our planet’s biodiversity is on the brink.

Some 1 million species are threatened with extinction right now. That’s more than any other time in history, and they’re disappearing at a rate that is 1,000 times the norm. The culprit is the way most humans consume, produce, travel, and live.

A 2019 UN report found that we have altered 75% of the planet’s terrestrial environment, 40% of its marine environment, and 50% of streams and rivers. Nearly three-fourths of our freshwater resources are devoted to crop or livestock production, which often means using pesticides, fertilizers, fuels, and antibiotics that pollute our rivers, streams, seas, and soil. Every day we are destroying habitats and degrading massive amounts of soil and water through industrial manufacturing and agriculture while jeopardizing precious natural resources that could be lost forever in our lifetime; in the past two decades, we’ve lost half of the planet’s coral reefs . Deforestation in the Amazon rainforest hit a record high last year; some 18% is gone already, with scientists warning that we’re approaching a tipping point toward potential collapse .

9. Sustainability is the only way forward.

Such irresponsible production and consumption of our natural resources come at a catastrophic cost. We are destroying our planet at an unprecedented rate and losing a vast number of plants, animals, insects, and marine life in the process — to the detriment of our own future. Humanity’s health and well-being are dependent on a biodiverse planet.

Fortunately, examples are emerging of a greener, more sustainable way of doing business. Circular economic models are becoming more common as companies realize the economic and environmental value of reducing, reusing, and recycling their supply chain. At the same time, more citizens are demanding sustainable sourcing and socially just labor practices from their consumer goods. In 2022, the founder of the outdoor retailer Patagonia announced plans to invest all of the company’s profits toward combating climate change . “If we have any hope of a thriving planet — much less a business — 50 years from now, it is going to take all of us doing what we can with the resources we have,” Yvon Chouinard wrote .

Along Brazil’s Rio Negro, fourth-generation logger Roberto Brito de Mendonça stands in the dining lodge of his community’s ecotourism lodge. He retired from the family business to help start the operation, which includes a newly built classroom named in honor of Dr. Lovejoy. PHOTO: Michael Dantas/United Nations Foundation

10. Indigenous communities are crucial.

For thousands of years, Indigenous communities have served as the planet’s most effective environmental stewards. Today, according to the UN, Indigenous people manage more than 20% of the planet’s land and 80% of its biodiversity. “For us, it is not a passion, or a job,” Hindou Ibrahim of the Mbororo tribe in Chad, an SDG (Sustainable Development Goal) Advocate and Indigenous rights activist, told the UN last year. “It is our way of living. And that’s what we have done for all generations.”

In 2015, the UN created the Local Communities and Indigenous Peoples Platform to ensure their formal participation in global negotiations on climate change.

11. Conservation is critical.

One of our most promising solutions is preservation. Restoring degraded ecosystems alone could provide up to one-third of the climate mitigation needed to keep the Earth from warming too far above pre-industrial levels. This means creating protected areas, curbing extractive capitalism, and restoring the planet’s enormous amount of degraded land.

People across the globe are leading efforts to do just that. One inspiring example is Rita Mesquita, who expanded the amount of protected rainforest in Brazil by 76% during her time in the country’s Ministry of the Environment. Today, she oversees programs that encourage residents and visitors alike in Manaus to interact with the surrounding Amazon rainforest.

A Rhinoceros Beetle in Costa Rica’s National Park Tortuguero. The rhino beetle is one of the strongest insects in the world with relation to its body size, but because its tropical lowland habitat has been deforested and overcut, it is struggling to survive. PHOTO: GRID-Arendal/Peter Prokosch

12. We need cooperation — and revolution — at all levels.

We need partnerships among countries, communities, consumers, and corporations. And we’re seeing signs of progress every day. In fact, at COP 27, the Governments of Brazil, Democratic Republic of Congo, and Indonesia announced an alliance to protect their respective rainforests. Their historic agreement could pave the way for more multilateral action and impact. Coming just a month later, the Kunming-Montreal Global Biodiversity Framework represents an enormous and long-awaited step toward halting extinction rates that some scientists are calling an existential crisis akin to climate change.

A huge part of the solution to the biodiversity challenge will be transforming how we approach the natural world and our place within it. As Dr. Lovejoy told the UN Foundation in 2018 , “There needs to be a major shift in perception from thinking of nature as something with a fence around it in the middle of an expansive, human-dominated landscape … to thinking about embedding our aspirations in nature.”

Biodiversity

Biodiversity refers to the variety of organisms found in a particular habitat. It is important to maintain biodiversity because we rely on it for ecosystem services, which fall into four main categories: provisioning, regulating, cultural, and supporting. The earth provides these to us for free and they are critical to achieving a planet in balance.

Biology, Ecology, Health

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• Published: 06 June 2012

Biodiversity loss and its impact on humanity

• Bradley J. Cardinale 1 ,
• J. Emmett Duffy 2 ,
• Andrew Gonzalez 3 ,
• David U. Hooper 4 ,
• Charles Perrings 5 ,
• Patrick Venail 1 ,
• Anita Narwani 1 ,
• Georgina M. Mace 6 ,
• David Tilman 7 ,
• David A. Wardle 8 ,
• Ann P. Kinzig 5 ,
• Gretchen C. Daily 9 ,
• Michel Loreau 10 ,
• James B. Grace 11 ,
• Anne Larigauderie 12 ,
• Diane S. Srivastava 13 &
• Shahid Naeem 14  

Nature volume  486 ,  pages 59–67 ( 2012 ) Cite this article

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• Biodiversity
• Ecosystem services

A Corrigendum to this article was published on 25 July 2012

The most unique feature of Earth is the existence of life, and the most extraordinary feature of life is its diversity. Approximately 9 million types of plants, animals, protists and fungi inhabit the Earth. So, too, do 7 billion people. Two decades ago, at the first Earth Summit, the vast majority of the world’s nations declared that human actions were dismantling the Earth’s ecosystems, eliminating genes, species and biological traits at an alarming rate. This observation led to the question of how such loss of biological diversity will alter the functioning of ecosystems and their ability to provide society with the goods and services needed to prosper.

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Acknowledgements

This work was conceived as a part of the working group, Biodiversity and the Functioning of Ecosystems: Translating Model Experiments into Functional Reality, supported by the National Center for Ecological Analysis and Synthesis, a Center funded by the National Science Foundation (NSF Grant EF-0553768), the University of California, Santa Barbara, and the State of California. Additional funds were provided by NFS’ DIMENSIONS of Biodiversity program to BJC (DEB-104612), and by the Biodiversity and Ecosystem Services Research Training Network (BESTNet) (NSF Grant 0639252). The use of trade names is for descriptive purposes only and does not imply endorsement by the US Government.

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School of Natural Resources and Environment, University of Michigan, Ann Arbor, 48109, Michigan, USA

Bradley J. Cardinale, Patrick Venail & Anita Narwani

Virginia Institute of Marine Science, The College of William and Mary, Gloucester Point, 23062, Virginia, USA

J. Emmett Duffy

Department of Biology, McGill University, Montreal, Quebec H3A 1B1, Canada,

Andrew Gonzalez

Department of Biology, Western Washington University, Bellingham, 98225, Washington, USA

David U. Hooper

School of Life Sciences, Arizona State University, Tempe, 85287, Arizona, USA

Charles Perrings & Ann P. Kinzig

Centre for Population Biology, Imperial College London, Silwood Park SL5 7PY, UK,

Georgina M. Mace

Department of Ecology, Evolution & Behavior, University of Minnesota, Saint Paul, 55108, Minnesota, USA

David Tilman

Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, S- 901 83 Umeå, Sweden,

David A. Wardle

Department of Biology and Woods Institute, Stanford University, Stanford, 94305, California, USA

Gretchen C. Daily

Station d’Ecologie Expérimentale, Centre National de la Recherche Scientifique, 09200 Moulis, France,

Michel Loreau

US Geological Survey, National Wetlands Research Center, Lafayette, 70506, Louisiana, USA

James B. Grace

Museum National d’Histoire Naturelle, 57, Rue Cuvier, CP 41 75231, Paris Cedex 05, France,

Anne Larigauderie

Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada,

Diane S. Srivastava

Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, 10027, New York, USA

Shahid Naeem

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Biodiversity

The term “biodiversity” is a contraction of “biological diversity” or “biotic diversity”. These terms all refer to the idea of living variation, from genes and traits, to species, and to ecosystems. The popular contraction “biodiversity” came about in the mid-1980s, heralded by a symposium in 1986 and an influential follow-up book, Biodiversity (Wilson 1988). These events often are interpreted as the beginning of the biodiversity story, but this mid-1980s activity actually was both a nod to important past work, and a launching of something quite new, in ways not fully anticipated.

The new term “biodiversity” energised some fundamental ideas developed over the previous decade (or longer). Precursor terms like “biotic diversity” had helped to communicate why we should be concerned about the loss of variety, arising from the species extinction crisis (later, the “biodiversity crisis”). This recognised the idea that living variation itself has current value, because it provides the opportunity for future benefits for humanity. The International Union for the Conservation of Nature (IUCN 1980) summarised these early ideas about variety as providing both “insurance” and “investment” benefits. The focus on the variety of life was echoed later in the Convention on Biological Diversity’s (CBD) definition of “biodiversity”, and in the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). The IPBES conceptual framework, describing “nature’s contributions to people” (Díaz et al. 2018), includes the maintenance of options for future generations that is provided by biodiversity as variety (see Faith forthcoming). This value of living variation complements recognised values of individual species, and it accords with the idea that “biodiversity” may refer both to the collection of individual species (or other units), and to amount-of-variation as a property of that collection.

The new term “biodiversity” also catalysed fresh new perspectives, with an explosion of academic and philosophical discussions, evidenced by the many post-1985 published papers having the key term “biodiversity”. Over this period, the term “biodiversity” often has reflected a range of different disciplinary perspectives (ecology, systematics, economics, social sciences, etc.). The range of conceptual issues addressed are reflected in recent books on the philosophy of biodiversity, including What is Biodiversity? (Maclaurin & Sterelny 2008), Biodiversity and Environmental Philosophy (Sarkar 2005), Routledge Handbook of Philosophy of Biodiversity (Garson, Plutynski, & Sarkar eds. 2017), Philosophy and Biodiversity (Oksanen & Pietarinen eds. 2004), and From Assessing to Conserving Biodiversity (Casetta, da Silva, & Vecchie eds. 2019) (see also the Related Entries section).

While the policy context for conservation of biodiversity has maintained a core focus on variety (as reflected in the CBD and IPBES definitions), the more academic discussions are harder to pin down. Philosophical discussions about “biodiversity” illustrate the current lack of academic consensus on fundamental issues, including biodiversity’s definition, its value, and even its history. Increased popularity of the term among academics has amounted to decreased clarity of the term. If we look under “Definition of biodiversity” in the Encyclopedia of Biodiversity , we find that “An unequivocal, precise, and generally accepted definition of biodiversity does not exist” (Swingland 2013). The recent book, Defending Biodiversity (Newman, Varner, & Linquist 2017) has the premise that it will be impossible to ever settle on a definition. This entry therefore will focus on these fundamental issues concerning biodiversity’s definitions and values. The particular focus is on the concept of variety (rather than the definition and value of individual elements such as species). Other biodiversity-related philosophical issues are covered in other SEP entries (see the supplementary document on biodiversity preservation in the entry on environmental ethics , and the entries on conservation biology and on ecology ).

1.1 Multiple benefits of biotic diversity: insurance and investment

2.1 further exploration of biodiversity option value, 2.2 variety, value and normativity, 2.3 what do we mean by “variety” or “diversity” and how do we measure it, 2.4 how understanding variety helps us build a working calculus of biodiversity, 3. beyond variety—post 1985 new “biodiversity” framings, 4.1 further exploration of biodiversity insurance value, 4.2 the rationale for the ecosystems framing, 4.3 definitions and values, 4.4 history, 4.5 concluding observations, 5.1 introduction, 5.2 biodiversity deflationism, 5.3 biodiversity eliminativism, 5.4 concluding observations, 6. socio-ecological framing, 7. concluding observations, other internet resources, related entries, 1. pre-history of “biodiversity”: variety and its values.

The term “biodiversity” was coined around 1985, but the conceptual, and political, foundations for the new term were developed over at least the previous decade. The link between biotic diversity and human well-being is clear in the “pre-history” of the term “biodiversity” (roughly, the history of the term before it was invented). Much of the early work recognising a species extinction crisis naturally focussed on the values of individual species to humanity, in addition to their intrinsic value (for reviews, see Farnham 2007; Mazur & Lee 1993). Discussions by Myers (1976) and others broadened this focus to include a concern about the consequent overall loss of variety, and why such a loss of variety itself matters to humanity. Haskins (1974: 646) summarised an important discussion meeting where participants called for

an Ethic of Biotic Diversity in which such diversity is viewed as a value in itself and is tied in with the survival and fitness of the human race.

Haskins (1974: 646) argued, “Plants and animals that may now be regarded as dispensable may one day emerge as valuable resources” and that extinction “threatens to narrow down future choices for mankind” (see also Anonymous 1974). Similarly, Roush (1977: 9) argued that “diversity increases the possibility of future benefits” (for review, see Farnham 2007).

Myers (1976) arguments for a greater focus on the overall loss of variety appeared in his paper, “An Expanded Approach to the Problem of Disappearing Species”. He argued that

…the spectrum of species can be reckoned a repository of some of society’s most valuable raw materials. Moreover, loss of species will affect generations into the indefinite future, whose options to utilize species in ways yet undetermined should be kept open. (see also Josephson 1982)

Myers and Ayensu (1983) similarly argued that the possible discovery of benefits for humans is a primary justification for conservation of biological diversity (see also Myers’ 1979 book, The Sinking Ark ).

This pre-history considered variety at more than the species level. Farnham (2017) provides a useful historical perspective, describing how the standard three levels of variation later recognised by the Convention on Biological Diversity (CBD)—genes, species, and ecosystems—became established early as parts of our broader concern about the loss of living variation. He describes this as a convergence of separate concerns about species loss, loss of genetic variety, and the disappearance of ecosystem types. Other support for this convergence is found in early work referring to the variety of biomes or ecosystems as capturing variety at the species level. For example, Ehrenfeld (1970) referred to the potential but unknown uses of species and suggested conserving the full variety of ecosystems to capture these future options (arguing that every ecosystem is likely to have some useful species). Back in 1972, the botanist, H. H. Iltis, argued that we must “preserve sufficient diversity of species and of ecosystems” because “we will never reach a point where we shall know which organisms are going to be of value to man and which are not” (Iltis 1972: 204). Ehrenfeld referred to the need globally to conserve a representative set of the different ecosystems (see also Roush 1977). Echoing these concerns, Wilson (1984) later lamented the lack of representativeness of the variety of ecosystems in the current protected areas system.

Thus, while important early discussion (Lovejoy 1980) linked “biological diversity” to species richness, the full spectrum of the early work reveals precedents for considering multiple levels—all with conceptual links to the species extinction crisis.

Those bits of pre-history clearly articulate the idea that variety itself is important because it maintains future options for humanity. However, this early work did not establish any consistent terminology to describe this. Later work (see below) uses terms like biodiversity “option value” (a term used in other ways in economics) and “maintenance of options” (a term that includes other contributions from nature, not just those from variety/biodiversity).

Back in 1980, the IUCN (International Union for Conservation of Nature) reflected on this earlier work, and offered some distinctions that are still useful in philosophical discussions about biodiversity definitions and values. IUCN’s (1980: section 3) arguments for the conservation of diversity (referring to “the range of genetic material found in the world’s organisms”) echoed earlier statements about variety and future options:

we may learn that many species that seem dispensable are capable of providing important products, such as pharmaceuticals….

Importantly, IUCN also echoed other early work, in adding a critical second part to that sentence: “…or are vital parts of life-support systems on which we depend” (IUCN 1980: section 3). IUCN provided terms for these two ways in which variety itself benefits humanity:

preservation of genetic diversity (their stand-in for the not-yet-defined “biodiversity”) is both a matter of insurance and investment to keep open future options. (IUCN 1980: section 3)

It is informative to trace this insurance and investment duality in the pre-history of “biodiversity”. Roush (1977) listed four reasons for preserving “natural diversity”. In addition to the relational values concerning “human delight” and ethics, his reasons included not only the idea that “diversity increases the possibility of future benefits” but also that diversity supports stability of the “life support system”.

Holdren and Ehrlich (1974) argued that loss of a species or loss of genetic diversity can mean loss of potential uses (medicines, foods etc.), but also referred to the maintenance of the “public service” functions of natural ecosystems. Ehrenfeld (1970) similarly distinguished between the within ecosystem functioning/stability argument and the potential uses or option value argument. Ehrlich and Ehrlich (1981), in their book Extinction discussed the insurance value of the Earth’s “biological diversity” through the analogy of popping rivets off an airplane wing—we strive to keep all the rivets, because we do not know how many could be lost before the wing no longer functions.

This pre-history of “biodiversity” thus considered multiple values for humanity from living variation itself, building on the even-longer history of basic awareness that there lots of kinds of things (e.g., species; for review, see Oksanen 2004). This argumentation also added to discussions that had considered attribution of “intrinsic value” to variety of life (see the supplement on biodiversity preservation in the entry on environmental ethics, for discussion of intrinsic value.

2. Later Work on Variety, Its Value, and the Question of Normativity

The new term “biodiversity”, post-1985, marked fresh perspectives about what variety or “diversity” might mean, and what the benefits and values of biodiversity might be. There also was a continuation and further development of the core perspectives on value established during the pre-history. Wilson (1985) made the case for a “biological diversity crisis” by arguing that this means the loss of potential uses, yet to be discovered. Wilson also echoed Myers and Ayensu (1983) and others arguing for the importance of systematics and the need for discovery of species to address knowledge gaps. Later, Wilson (1988) brought these arguments together, arguing that the new term “biodiversity” reflects our lack of knowledge about the components of life’s variation and their importance to humankind.

The pre-history perspectives, in the writings of Myers and others, influenced the Brundtland Report, a landmark United Nations report on sustainable development (WCED 1987). This report contains the much-quoted definition:

Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

This is followed by a key requirement:

The loss of plant and animal species can greatly limit the options of future generations; so sustainable development requires the conservation of plant and animal species.

The report’s call for governments to form a “species convention” helped catalyse the creation of the Convention on Biological Diversity (CBD; see below).

These perspectives foreshadow later discussion themes, including: further exploration of biodiversity option value (including the question of normativity); analysis of what we mean by “variety” and how we measure it; and further exploration of the “insurance” aspect of biodiversity value (setting the stage for a multitude of ecological interpretations of “biodiversity”).

Post 1985, the new term “biodiversity” was central to perspectives on the value of living variation. McNeely (1988) and Reid and Miller (1989) highlighted option values of biodiversity (see also Norton 1986). Later, a landmark global report, the Millennium Ecosystem Assessment (2005: 32), summarised twenty-plus years of “biodiversity” conservation, concluding that

the value individuals place on keeping biodiversity for future generations—the option value—can be significant.

Another decade later, Gascon et al. (2015) reviewed the many, often surprising, benefits of species to argue for the importance of biodiversity option value. Gascon et al. also echoed the earlier proposals that “phylogenetic diversity”, a measure of biodiversity based on the tree of life, is a natural way to measure this option value (see section below).

Around that time, the Papal Encyclical Letter “On Care for Our Common Home” (Francis 2015) addressed the loss of biodiversity, arguing for the importance of not only intrinsic values of species but also the option values of biodiversity:

The loss of forests and woodlands entails the loss of species which may constitute extremely important resources in the future, not only for food but also for curing disease and other uses. Different species contain genes which could be key resources in years ahead for meeting human needs and regulating environmental problems. (2015: 32)

These arguments referring to surprising benefits from individual species sometimes have not make it clear whether such values are being considered for individual species (only), or for variety itself. The IPBES Conceptual Framework (Díaz et al. 2015: 14) refers to

the “option values of biodiversity”, that is, the value of maintaining living variation in order to provide possible future uses and benefits.

However, later IPBES discussions of “nature’s contributions to people” use related terms in a more general way. Here, Díaz et al. (2018: Table S1) describe “maintenance of options” as the “Capacity of ecosystems, habitats, species or genotypes to keep options open in order to support a good quality of life”. This broad statement seems to cover both individual elements and variety itself.

Bartkowski (2019) in his “Valuation of Biodiversity” review, notes that perspectives about economic values of “biodiversity” typically have focussed on individual elements, with the less-attention to the values of variety, including both option and insurance values. This concern echoes earlier debates that have examined whether option value applies to biodiversity-as-variety, and not just to specific elements. Consideration of the potential future benefits from individual species can be interpreted as implying a value for variety (Maclaurin & Sterelny 2008: 154):

The crucial point about option value is that it makes diversity valuable. As we do not know in advance which species will prove to be important, we should try to conserve as rich and representative a sample as possible.

Maier (2012), in his book, What’s So Good About Biodiversity? , criticised Maclaurin and Sterelny’s arguments for biodiversity’s option value. However, this critique may reflect simply a focus on individual elements rather than variety itself. Maier interpreted “option value” as applying, in accord with economics usage, to a given element, resource, or ecosystem service. Any quantification of value, Maier argued, would require estimates of reliability of stock, risk aversion, and willingness to pay—all missing in Maclaurin and Sterelny’s arguments. These views are partly reconciled by recognising that reference to “option value of biodiversity” is a current value of variety itself, and does not have to be interpreted to mean that the actual value of the future benefits is determined. This difference in perspectives also has played a role in debates about whether biodiversity option value has normative standing.

Biodiversity as variety provides option/investment and insurance benefits to humanity, but this leaves open the question as to the nature of the value of such benefits. Haskins (1974) had called for “an Ethic of Biotic Diversity”, in which variety’s benefit has ethical import because we care about the well-being of future generations. Similarly, when IUCN (1980: Section 3) reviewed the arguments for the conservation of biotic diversity, they linked this to moral principles:

The issue of moral principle relates particularly to species extinction, and may be stated as follows. Human beings have become a major evolutionary force. While lacking the knowledge to control the biosphere, we have the power to change it radically. We are morally obliged-to our descendants and to other creatures-to act prudently… We cannot predict what species may become useful to us. Indeed we may learn that many species that seem dispensable are capable of providing important products, such as pharmaceuticals, or are vital parts of life-support systems on which we depend. For reasons of ethics and self-interest, therefore, we should not knowingly cause the extinction of a species.

This early discussion, linking biodiversity’s option value to ethical/moral obligations to future generations, anticipated the rationale for the Convention on Biological Diversity (CBD). Schroeder and Pisupati (2010: 9) in “Ethics, Justice, and the Convention on Biological Diversity”, note that the CBD statements on conservation of biodiversity include consideration of intergenerational justice:

The first CBD objective, the conservation of biodiversity, is an urgent act of attaining intergenerational justice; an act that requires sustained, engaged international collaboration. To deplete the planet of essential resources and leave to future generations a world which severely limits their options, is unjust.

In this context, biodiversity is valued (now) because we care about the welfare of future generations; thus, we see a current benefit, and a link to justice, in biodiversity’s maintenance of options for future generations. This is seen as a kind of relational value, relating the present generation to future generations (Faith 2017: 76):

the best argument for what we call the option value of biodiversity is that we see many currently beneficial units, and maintaining a large number of units (biodiversity) for the future will help maintain a steady flow of such beneficial units… Biodiversity option value therefore links “variation” and “value”: providing a fundamental relational value of biodiversity reflecting our degree of concern about benefits for future generations

Intergenerational justice or equity is linked to both investment/options and insurance (Bartkowski 2017: 53):

…the two perspectives—insurance and options—are inherently interlinked; however, they depend on different types of uncertainty (supply vs. demand), which makes the differentiation sensible. The view of biodiversity as carrier of option value stems from the recognition that a biodiverse ecosystem, which contains many different species and genomes, can best accommodate unanticipated future desires (preferences). As in the case of insurance value, this can be coupled with considerations of intergenerational equity. In fact, in the case of option value, this notion is arguably more central: high levels of biodiversity now mean many different options for our descendants.

An important consideration in recognising an ethical/moral/justice imperative to conserve biodiversity is the recognition that biodiversity, as variety, has a current benefit/value because of that relational link between generations. However, other framings omit this idea of a current benefit from variety itself. For example, Binder and Polasky (2013), in the Encyclopedia of Biodiversity , list ways that biodiversity links to human well-being.

Biodiversity contributes to human well-being directly through provision of foods, fuels, and fibers, and indirectly through its role in enhancing ecosystem functions that lead to the provision of ecosystem services.

This might seem to capture biodiversity option value in referring to foods and other goods, but in fact leaves out the idea that society sees biodiversity and the prospect for discoveries for future generations as a current contribution to well-being. The well-being is not just that realised when the new product is discovered.

Such a restricted interpretation can mean that the maintenance of options provided by biodiversity fails to enter into assessments. For example, Brauman et al. (2020) set out to assess the current global status of nature’s contributions to people, but explicitly chose not to assess maintenance of options—arguing that this is a contribution to well-being only through its support of the well-being obtained from other contributions of nature. In contrast, the IPBES global assessment (IPBES 2019) did assess global status of maintenance of options, noting that, even when considering other specific nature contributions, such as medicinal resources, biodiversity’s maintenance of options is a current benefit in promising possible future medicinal benefits (see also “Phylogenetic diversity and IPBES” in Other Internet Resources).

Absence of recognition of the current benefit of biodiversity’s maintenance of options has other implications. Maier’s (2018) arguments that biodiversity option value has no normative standing are based on an assessment of variety as a future, not current, benefit. An alternative argument, supporting normative standing, focuses on biodiversity-as-variety as a current benefit, because this variety is recognised as maintaining options for future generations. This current value links to normativity—we ought to act to conserve biodiversity and its maintenance of options because it is the right thing to do, given that we care about, and have some relational moral obligation to future generations (Faith 2018a). These discussions highlight the idea that both “current benefit” and “future benefit” are relevant to biodiversity option value. Biodiversity is a benefit currently because it offers unanticipated future benefits, and given the relational sense of obligation to future generations is a basis for normativity.

Another entry in the Encyclopedia of Biodiversity , Chan and Satterfield’s (2013) “Justice, Equity and Biodiversity”, supports this idea, in linking biodiversity conservation to justice for future generations. However, “biodiversity” is left undefined, and seen as something that exists within ecosystems that maintains ecosystems services for future generations. The focus on ecosystem services (where “biodiversity” often has ecological interpretations; see section below) means that the value of variety itself is left unstated by the authors.

Some perspectives give less emphasis to the idea of variety and its benefit/value, and in these, the arguments for a normative status for “biodiversity” appear to be weaker. For example, Koricheva and Siipi (2004: 46) see only intrinsic value as a pathway for moral obligation to (overall) biodiversity:

If biodiversity is found to be intrinsically valuable, we have strong moral reasons to conserve all aspects of biodiversity, regardless of their potential utilitarian and instrumental values. If, conversely, biodiversity is found to be only instrumentally valuable, then on moral grounds we can demand conservation only of those parts which (directly or indirectly) enhance (or will in the future enhance) the well-being or quality of some other valuable entity or state of affairs.

Given this perspective, they conclude that: “conservationists are burdened with the need to find or create instrumental values for each biodiversity element”. Similarly, in “The Moral Value of Biodiversity”, Oksanen (1997) concludes that “It is not the thing ‘biodiversity’ that is of ultimate moral value, but its various constituents”. Thus, this argumentation seems to be disconnected from the idea that, collectively, all of the “elements” or “constituents”—the variety—delivers biodiversity option value and justice for future generations.

Significantly, the popular instrumental-versus-intrinsic argumentation has sometimes meant a neglect of biodiversity option value. [ 1 ] Commonly, the instrumental value of biodiversity is characterised as all about supporting of functions/resilience within ecosystems, not global option values. Some literature suggests that relational values importantly move beyond the standard instrumental-versus-intrinsic framework (e.g., Himes & Muraca 2018). In the context of biodiversity option value, greater appreciation of relational values in fact restores a link to biodiversity value that has been obscured by the popular instrumental-versus-intrinsic argumentation.

The link to variety, as compared to individual elements and/or other ecosystem/ecological aspects, is an issue in other discussions. Eser et al. (2014) acknowledge a normative content for biodiversity, and consider it as arising from the politics at that time (“the making of the term ‘biodiversity’ indicates that the concept is morally impregnated”, 2014: 38). They argue that

the Convention on Biological Diversity, not only addresses issues of conservation, but also sustainable use and fair sharing of benefits. This triad of objectives reflects the three dimensions of sustainable development: ecology, economy and society. (2014: 38)

This equation may imply that the justice/normativity link is to be interpreted as depending on the “fair sharing of benefits”. This fair sharing of benefits often is played out locally, while the conservation of biodiversity is more a global CBD issue. Thus, there does not seem to be a tight fit between Eser et al.’s historical perspective, tied to the origins of the term “biodiversity”, and the deeper historical perspective of ethical arguments for the conservation of biotic diversity. Indeed, Eser et al. do not provide any explicit analysis of the benefits and value of biodiversity-as-variety. Instead, they see the wide range of notions of “biodiversity” as quite useful in providing a “boundary” object that can embrace lots of meanings and perspectives about value. A similar perspective is found in a proposed “weak deflationism” for biodiversity (see below), where what is regarded as “biodiversity” is the outcome of “normative discussion of what merits conservation”.

Eser et al.’s arguments nevertheless are compatible with the early ideas, going back to Haskins and others, of a normative reason to protect biodiversity-as-variety for future generations. Significantly, Eser et al. (2014: 94) argue that:

consideration of the needs of future generations does not count as “nice to have” but is considered a “must”. Finding the appropriate balance between obligations to current and future generations is one of the main challenges of global change ethics.

Eser et al. conclude (2014: 95)

the moral belief that our dealing with the needs of future generations is a matter of Justice is so widespread that it can almost count as a truism. To substantiate biodiversity strategies with the rights of future generations therefore is a promising strategy because it meets the intuitions of so many people.

During the pre-history of “biodiversity”, the species extinction crisis provided motivation to consider the value of living variation, covering not only species richness but also genetic variation and the variety of ecosystems. The new term “biodiversity” introduced fresh considerations, particularly reflecting ecology and ecosystems perspectives. The CBD definition of “biodiversity” used two terms, “variability” and “diversity”, that have invited multiple interpretations:

… the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.

The definition of “biodiversity” in the IPBES Glossary (see the link in Other Internet Resources ) partly follows that of the CBD:

The variability among living organisms from all sources including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part. This includes variation in genetic, phenotypic, phylogenetic, and functional attributes, as well as changes in abundance and distribution over time and space within and among species, biological communities and ecosystems.

The vague open-ended term “diversity”, in the CBD definition, can be interpreted as any of a number of ecological diversity indices (see below). In contrast, IPBES reflects pre-history in shifting to the word, “variation”. Naturally, this word has provided its own interpretation challenges, including how to characterise it consistently across different levels of variation. Weitzman (1992) presented an influential general framework for biodiversity as variation, based on the idea of objects, and measures of difference between objects. Biodiversity (amount of variation) then depends not only on the number of objects, but also the degree of differences among them. In the book Philosophy and Biodiversity , the link between “biodiversity” and investment and insurance value is described as depending on: “The higher the number and the degree of difference between biological elements” (Koricheva & Siipi 2004: 39). Weikard (2002) argued that any operational concept of biodiversity must have some measure of difference between objects (see also Maclaurin & Sterelny 2008; Morgan 2009).

This strategy assumes that we can define meaningful differences among the initial objects, and also sort out the trade-off between having more objects versus bigger differences. One difficulty is that there are many ways to define “differences”. Morgan (2009) concluded that, even if one has some agreed natural measure of differences, we do not know how to trade off more objects for less differences (or vice versa) to assess biodiversity.

An alternative general framework, proposed by Faith (1994), avoids weaknesses of the objects-differences strategy. The framework side-steps the idea of differences and instead uses the inferred relative number of biodiversity “units” among any given set of “objects”. If “biodiversity” is variation or variety in the sense of units (such as species) that we ideally count-up, then what are those units or elements that make-up biodiversity? The units of interest logically cover more than just the species level (and even the core idea of “species” may consider alternative classifications, such as those in folk cultures; Oksanen 2004). Maclaurin and Sterelny’s argument (2008: 154) that option value “links variation and value” considered option value for units across all levels of biodiversity.

A common assessment of biodiversity-as-variety evaluates a set of protected areas and asks “how many different species are represented by that set of areas?” In the general framework, this converts to a more general biodiversity question: “how many different units are represented by that set of objects?” Thus, “species” corresponds to just one kind of “unit” of variation (with different species as different “units”), and areas are just one kind of “objects”. Biodiversity assessment considers a wide range of these possible objects for decision-making—not just areas, but also species, populations, and other entities. Biodiversity therefore can be quantified in general as a count of the number of different units represented by a given set of objects. Examples of other objects/units combinations include species/traits (or features) and species’ populations/genetic variants.

A strength of the framework is that it addresses the fact that many of the “units” are unknown, and so, cannot simply be counted-up. Many species are still unknown to science; many features of species are undescribed. We may directly observe some objects (say, species) and want to quantify the relative number of un-observed units (say, features) that are represented by those objects. The relative number of units for any object or set of objects therefore has to be estimated through the use of an inferential model or a surrogate of some kind.

A model that successfully reflects the underlying processes that determine the distribution of units among objects (a pattern—process model) may tell us enough about the relationships among the objects to enable inference of relative numbers of units represented by any set of those objects. This is the rationale for a general framework for using pattern to quantify diversity at a level below that of the original objects.

Thus, relationships among different objects ) informs us about what is of interest: the amount of biodiversity, expressed as the number of units represented by those objects. This “counting-up” of the lower-level units means that we can compare different sets of objects by the count of the number of different units represented, and look at useful information such as gains and losses as the set changes.

Suppose, for example, that the units of interest are features of species (a feature might be some morphological characteristic). These features in general have unknown future benefits; feature diversity provides another example of biodiversity option value. If we apply the rationale that all these features should be treated as units of equal value, then some species (those that are phylogenetically distinctive; see below) will make larger contributions to the overall feature diversity represented by a set of species. Thus, equal value at the fine scale among features leads to differential values at the coarse scale among species.

Feature diversity raises measurement challenges. Not only do we not know, in general, the future value of different features, but also we cannot even list the features for most species. Phylogenetic pattern provides one way to estimate and quantify variation at the feature level. The predicted total feature diversity of a set of species is referred to as its “phylogenetic diversity” (PD). The amount of PD, and the estimated relative feature diversity, of a set of species is calculated as the minimum total length of all the phylogenetic branches required to connect all the species in that set on the phylogenetic tree (Faith 1992). This definition follows from an evolutionary model in which branch lengths reflect evolutionary changes (new features), and shared ancestry accounts for shared features among species. Note that a set of three species may have lower PD (lower feature diversity) than a set of two species (see figure below).

The phylogenetic diversity measure illustrates how the pattern—process framework differs from the objects and differences approach. For PD, the objects are species (or other taxa) and the units that we would like to count-up are features (or characters). The use of phylogeny (the “tree of life”) to make inferences about the relative feature diversity of different sets of species is a way to overcome our lack of knowledge about all the features of different species. Maclaurin and Sterelny (2008: 20) incorrectly interpreted PD as an application of the objects and differences approach, with species as objects and differences given by “genealogical depth”. Instead, a pattern (phylogeny) among the species is used. This pattern allows inferences about the biodiversity units of interest—here, features or characters of species.

Figure. A general biodiversity model linking relationships among objects to measures of biodiversity based on the indirect counting-up of units. In each case, relationships among the three objects represented by solid dots provides information about their representation, as a set, of underlying units. The ovals highlight the idea that their degree of similarity within the pattern indicates degree of shared units.

for phylogenetic diversity, the objects are species, the units are evolutionary features and the phylogenetic/feature diversity of the 3 (solid dots) species is indicated by the summed lengths of the blue branches on the phylogenetic tree. Note that this set of 3 species has greater phylogenetic diversity / feature diversity than the set of two hollow-dot species (red branches). [An extended description of figure (a) is in the supplement.]

another kind of pattern for species-as-objects is a Euclidean space representing key environmental gradients. The inferred biodiversity may be functional trait diversity. [An extended description of figure (b) is in the supplement.]

Sarkar’s (2014: 3) consideration of “units” other than species appears compatible with the general pattern–process framework. However, Sarkar’s proposal differs in integrating other additional calculations into the quantification of biodiversity. For example, Sarkar proposed that biodiversity must include a number of aspects beyond richness. At the species-level, Sarkar (2014: 3) argued that a measure of biodiversity should reflect complementarity, rarity, endemism and also “equitability” (reflecting relative abundances). Another aspect to be included was “disparity” reflecting taxonomic distance between species. Sarkar’s consideration of a taxonomic measure of difference between species as part of “biodiversity” echoes the popular objects and differences strategy.

Possible proposals to include aspects beyond richness (counting units) seem limitless. This problem highlights the advantages of a simpler framework where “biodiversity” focuses on the number of units, while recognising that the same units can be part of numerous other calculations that include standard ecological indices. Thus, complementarity, endemism, and dissimilarities and many traditional ecological “diversity” measures all can be calculated, but they are not measures of “biodiversity”.

The framework based on counting-up units contrasts with other proposals for general frameworks for biodiversity, including those proposals that have attempted to include a variety of calculations—endemism, dissimilarity, rarity, etc.—within the definition of biodiversity (see below). The framework based on counting-up units implies not only that biodiversity as variety is that total count, but also that we can carry out lots of other important, associated, calculations that will be useful for decision-making and policy—notably looking at gains and losses. This idea of a biodiversity “calculus” contrasts with the ecologically oriented perspective that there are many different indices called “biodiversity”.

One important companion calculation is called “complementarity” (Kirkpatrick 1983)—the gains and losses in biodiversity as objects are gained or lost. While biodiversity is quantified by an inferred count of number of different units, decision-making about biodiversity uses various calculations based on those units. Complementarity usefully indicates marginal changes—the number of units lost, or the increase in the number represented by an added protected area. Faith (1994) focussed on complementarity as an example of useful calculations (referred to as “components of biodiversity”) based on inferred counts of units:

The problem of prioritising areas illustrates how pattern (specifically environmental pattern) can be used as a surrogate for biodiversity, in predicting the same components of biodiversity that would be used at the species level directly, notably complementarity.

The approach using environmental pattern for such calculations can be generalised to cover other patterns to make inferences about underlying units. For PD, the pattern is phylogeny and a species’ complementarity reflects the relative number of additional features contributed by that species. PD decision-making sometimes uses calculations that are integrated with species’ estimated extinction probabilities—extending the idea of complementarity to “expected” loss. Priorities for conservation efforts for endangered species then can respond both to degree of threat and to amount of potential loss of PD. One such conservation program is the EDGE of Existence program (“evolutionarily distinct and globally endangered”; see the link in Other Internet Resources ).

By recognising other calculations as useful, but not equated with “biodiversity”, and by side-stepping the weaknesses of the objects-differences framework, we can focus on counting-up different units, and focus on the value of having many different units. Thus, the idea of a useful calculus further reinforces the role of biodiversity-as-variety in providing option and insurance values.

This perspective is relevant to the second part of the IPBES definition of biodiversity (above), where “biodiversity” is to include various measures of “change” in distribution, abundance etc. This perhaps reflects the ecology perspectives in which “biodiversity” is equated with various ecological indices and calculations, such as dissimilarity or relative abundance. Sometimes it is not at all clear how the key idea of “biodiversity loss”—complementarity—applies in such cases. This issue is addressed further in the section below on ecology and ecosystems framings.

The IPBES definition illustrates the trend to include many other biotic/ecological aspects in the definition. Popular encyclopedia entries on “biodiversity” and major reviews illustrate how this trend has contributed to definitional chaos. In the Encyclopedia of Biodiversity , Swingland argues “An unequivocal, precise, and generally accepted definition of biodiversity does not exist”. in the Routledge Handbook of the Philosophy of Biodiversity , nearly every chapter discusses the “biodiversity” definition problem. The SEP entry supplement biodiversity preservation under environmental ethics laments “A persistent complication is that there continues to be no single agreed measure of biodiversity”.

Koricheva and Siipi (2004) observe that

biodiversity still lacks a universally agreed upon definition and is often redefined depending on the context and the author’s purpose.

They suggest that:

Such great terminological variation is understandable, since concerns for biodiversity relate to several realms of human practice, including conservation, management, economics, and ethics, and thus give rise to different “discourses”. (2004: 28)

The common measure, species richness, illustrates the different perspectives. The pre-history of biodiversity, reflecting the species extinction crisis and the values of variety, provides a core rationale for a definition that includes counting-up species. In contrast, Koricheva and Siipi (2004) argue that popularity of species richness (as a measure) continues simply because it is understandable, measurable, and it uses available information (see also Sarkar 2019). A section below (“the Conservation Biology framing”) returns to this issue, in considering a perspective that assumes that the “biodiversity” concept arose as part of the new discipline of conservation biology in the mid-1980s.

The pre-history of “biodiversity” also highlighted the idea that the value of variety itself should be considered along-side the recognised benefits (and dis-benefits) of individual species (“biospecifics”), and all these benefits/values can enter into trade-offs and synergies that support decision-making. Some current perspectives or framings about biodiversity and its value can be understood as again blurring that distinction between biodiversity and “biospecifics”. One such framing equates “biodiversity” with all of nature. A focus on “biodiversity” as the collection of individual units/elements suggests that “biodiversity” covers so many individual elements that it more or less can be equated with biotic “nature”. An ecological/ecosystem framing of biodiversity expands this further—“biodiversity” may be interpreted as including not only the many individual elements but also all their ecological interactions, and associated processes. These expanded perspectives, focused on elements and their interactions, create a risk that we may miss the opportunity to properly consider both values of nature/ecology and the values associated with biodiversity-as-variety.

Several factors may help to explain the current wide range of perspectives about biodiversity’s definition and values. One is the idea that the term “biodiversity” was intended to capture everything we wish to conserve within the discipline of conservation biology. Another is the idea that “biodiversity” only gains meaning and importance to humanity in supporting ecosystem functions and services. Both of these framings are supported by particular interpretations of the history of the concept. More recently, another emerging perspective is a call for a re-casting of the term “biodiversity” to make it more holistic in reflecting socio-ecological thinking. The themes outlined above roughly correspond to three kinds of re-framings of “biodiversity”, defining the next three sections below: §4 the ecology/ecosystem services framings , §5 the conservation biology framing , and §6 socio-ecological framings .

4. The Ecology/Ecosystem Services Framings

“Ecosystem services” are all the benefits that humanity derives from ecosystems (Daily 1997). While that term is probably younger than the term, “biodiversity”, it not only has its own pre-history (as “natural services” from nature; see, e.g., Holdren & Ehrlich 1974), but also shares a pre-history with “biodiversity”. This history reveals early ideas about how aspects of biotic diversity are important to maintaining the ecological functions that support ecosystem services. These discussions drew upon the long tradition in ecology to use various ecological indices—broadly referred to as “diversity” indices—and so inviting equation with the new term “biodiversity”. Exploring this connection between biotic diversity, ecological functions, and services has become a massive research venture over the past 25 years (for review, see, e.g., Gómez Baggethun et al. 2010). The name of the international platform for biodiversity, “Intergovernmental Platform on Biodiversity and Ecosystem Services” (IPBES), reflects this active, high-profile, connection.

The ecosystem services framing of “biodiversity” interprets the many aspects of “diversity” that link to functions and services as part of a “biodiversity” narrative. This narrative is interpreted as the basis for a rationale for conserving biodiversity, because it is claimed to link biodiversity, for the first time, to benefits for humanity.

The insurance and options benefits from living variation recognised in the pre-history, also appear in later work, using the new term “biodiversity” (e.g., Bartkowski 2017). Post 1985, such discussions continued to follow the pre-history in considering the value of variety itself for insurance. However, alternative perspectives focussed more on the early discussions pointing to a broader ecological/ecosystem interpretation of insurance and related ideas such as “ecological integrity”.

IUCN (1980) described “ecological integrity” as:

Maintaining the diversity and quality of ecosystems and enhancing their capacity to adapt to change and provide for the needs of future generations.

Sometimes this more ecological rationale has been discussed as part of a new “biodiversity” framing, so setting the stage for ecological definitions of “biodiversity”.

For example, Ehrlich and Wilson (1991) listed three basic reasons why we should care about biodiversity. The first was most closely linked to intrinsic value: a “moral responsibility to protect what are our only known living companions in the universe”. Their second reason reflected the option value of biodiversity—the idea that

humanity has already obtained foods, medicines, and industrial products and other benefits from biodiversity, and has the potential for many more.

Their third reason was an insurance type argument, based on the recognised ecosystem services provided by natural ecosystems. Here, they made a link to biodiversity in arguing that “diverse species are the key working parts” within such ecosystems.

“Working parts” could mean variety, or it could refer to the ecology of lots of parts in an ecosystem. In earlier work (Ehrlich & Ehrlich 1981) “insurance” was linked to the loss of biological diversity and so linked to variety. Ehrlich and Ehrlich’s (1992: 219) later arguments for biodiversity conservation referred both to option value (from variety expressed as nature’s “genetic library”), and to insurance value—expressed less as variety and more as a consideration of ecological aspects. Thus, “insurance” sometimes joins “ecological integrity”, and similar terms as part of a storyline about many relevant aspects of ecosystems.

Similarly, the Millennium Ecosystem Assessment (2005) described the multiple values of biodiversity in a way that reinforced the duality of insurance and option values from variety, but also linked “biodiversity” to ecological aspects, including resilience and integrity.

The ecosystem services framing builds on the important idea that ecosystems provide many, often under-appreciated, benefits to people (clean water, useful resources, etc). It is natural to consider that these benefits provide a case for conservation of “biodiversity”. The ecosystems framing adopts the perspective that it is “biodiversity”—typically, interpreted broadly as ecological “diversity”—that is the basis for these important functions and services. This framing reduces the focus on variety of species or other elements (in the sense of counting-up). Perhaps because of the natural within-ecosystems focus, this also has amounted to lesser emphasis on global scale option value from such variety. The ecosystems framing reflects this perspective in the range of “biodiversity” definitions considered. The idea that “biodiversity” is important for ecosystem services is given support by defining “biodiversity” in terms of those ecological factors that are important for ecosystem services.

Noss (1990) regarded biodiversity as including composition, structure, and function, reflecting the range of “diversity” measures in ecology (ecological diversity indices are reviewed in Koricheva & Siipi 2004). The CBD’s use of the general term, “diversity” (see above) has provided a broad canvas for interpretation of “biodiversity” in a framing focussed on ecosystems. The now popular ecological definitions of “biodiversity” are exemplified in the Routledge Handbook of Ecosystem Services :

Biodiversity broadly encompasses the number, abundances, functional variety, spatial distribution, and interactions of genotypes, species, populations, communities, and ecosystems. (Balvanera et al. 2016: 46)

Díaz et al. (2009: 55) describe “biodiversity” as

the number, abundance, composition, spatial distribution, and interactions of genotypes, populations, species, functional types and traits, and landscape units in a given system.

Mace, Norris, and Fitter (2012) argued that the definition of “biodiversity” “embraces many alternative diversity measures” (see also Hillebrand et al. 2018), and highlighted “biodiversity” as species composition: “the composition of biological communities in the soil” is an example of how “biodiversity is a factor controlling the ecosystem processes that underpin ecosystem services” (2012: 22).

This broad use of diversity measures recalls early work linking various ecological diversity indices to “stability” and other desirable aspects of ecosystems (for review, see the SEP ecology entry). In the ecosystems framing, “biodiversity services” are defined in terms of ecological processes:

Biodiversity is structured by a range of ecological processes ….These processes—which can be termed “biodiversity services”—underpin and determine the stability, resilience, magnitude and efficiency of the functions and properties of ecosystems. (Seddon et al. 2016: 7)

This characterisation neglects the previous use of this same term to refer to global biodiversity option value (see Faith 2018b). Similarly, Norton (2001) pointed to increased emphasis on processes that under-pin ecological “health” or “integrity”, and de-emphasis of a conventional elements-oriented perspective for biodiversity.

These ecological definitions of “biodiversity” have influenced some perspectives about biodiversity values. The Encyclopedia of Biodiversity chapter on “The Value of Biodiversity” (Dasgupta, Kinzig, & Perrings 2013: 168), reflects the ecosystems framing in claiming that:

The value of biodiversity derives from the value of the final goods and services it produces. To estimate this value, one needs to understand the “production functions” that link biodiversity, ecosystem functions, ecosystem services, and the goods and services that enter into final demand.

“Option value” is mentioned in the chapter, but is linked to a “resource”, not to variety itself.

This framing is reflected also in the 2019 review, “The Economic Value of Biodiversity”, by Hanley and Perrings. It focuses on ecosystem services, and does not mention the investment value of biodiversity-as-variety. Similarly, in the Encyclopedia of Biodiversity chapter on “Sustainability and Biodiversity” (Cavender-Bares et al. 2013: 73), the value of biodiversity is based on its relationship to ecosystem functions, and their value of in terms of human well-being. Thus, the ecosystems framing tends to focus on within-ecosystem values and tends to ignore global values including option value.

A core perspective in this framing is that “biodiversity” is about critical ecological elements:

A major criticism of the valuation approach to conserving biodiversity is that current understanding of the mechanistic links between species and the functioning and resilience of ecosystems is far from complete…. Without this, we may fail to protect those elements of diversity crucial for ecosystem integrity. (Seddon et al. 2016)

A within-ecosystems focus, and typical neglect of global biodiversity option value, sometimes has been supported by an accounting in which “biodiversity” historically had been recognised as all about intrinsic value, until the ecosystem services framing forged links for the first time to anthropocentric values (for discussion, see Faith 2018b).

The rationale for the ecosystem services framing presents two principal approaches to conservation:

Caricaturing slightly, the first is focused on biodiversity conservation for its own sake, independent of human needs or desires. The second is focused on safeguarding ecosystem services for humanity’s sake: for the provision of goods, basic life-support services, and human enjoyment of nature. (Balvanera et al. 2001: 2047)

The ecosystems framing sees the ongoing loss of biodiversity as a values failure that calls for a shift to ecosystem services values:

Despite appeals about the intrinsic value of nature and important gains in some areas, the dominant flow of human activity has continued moving in directions detrimental to biodiversity conservation … In response, some within the conservation community have attempted to broaden the base of support for biodiversity conservation by adopting the concept of ecosystem services and by arguing that the conservation of biodiversity matters not only because of its intrinsic value but because it is essential for human well-being. (Reyers et al. 2012: 503)

Thus, in this historical accounting the ecosystems framing forged the first links from “biodiversity” to anthropocentric values.

A popular history of ecosystem services (Gómez Baggethun et al. 2010) similarly presents the original motivation for considering ecosystem services as helping biodiversity conservation:

It starts with the utilitarian framing of beneficial ecosystem functions as services in order to increase public interest in biodiversity conservation (Westman 1977…). (Gómez-Baggethun et al. 2010: 1209)

In reality, Westman did not refer to biodiversity (nor “biotic diversity”). Instead, Westman linked functions to various aspects of ecology, including “how components of the system interact” (1977: 961) and “the flow of materials and energy” (1977: 963).

Customised narratives in the ecosystem framing are apparent also in Peterson et al.’s (2018: 1) reference to:

the notion of the “maintenance of options” type of nature’s contributions to people (NCP 18; Díaz et al. 2018), enhancing “the capacity of ecosystems to keep options open in order to support a good quality of life” (Díaz et al. 2018: SM).

This would seem to make a strong case for a focus on ecosystems, but Peterson et al. misquote this foundational paper on NCP. “Maintenance of options” in fact is described (Díaz et al. 2018: Table S1) as the “Capacity of ecosystems, habitats, species or genotypes to keep options open in order to support a good quality of life”. The misrepresentation gives the impression that the maintenance of options is only about how ecosystems support human-well-being.

The shift by IPBES away from an ecosystem services framing in favour of a broader “nature’s contributions to people” (NCP; for discussion, see Díaz et al. 2018, 2019; Faith 2018b) reflected, in part, the need to better address global/regional biodiversity values:

It has to be recognized that the concept of “nature’s contributions to people” has evolved in a context where challenges related to the loss of biodiversity are addressed and assessed on global and regional levels. The implications of this widening from the ecosystem service framework … is largely an issue that remains to be explored. (IPBES 2018a)

The IPBES regional and global assessments (IPBES 2018b,c, 2019) advanced this wider conceptual framework through the use of a measure of biodiversity-as-variety, phylogenetic diversity, as an indicator of the global status of the maintenance of options (see link to “Phylogenetic diversity and IPBES” in Other Internet Resources).

5. The Conservation Biology Framing

Sarkar (2017: 43) summarises the basis for what might be called the conservation biology framing of “biodiversity”:

the term “biodiversity” and the associated concept(s) were introduced in the context of the institutional establishment of conservation biology as an academic discipline….

The SEP conservation biology entry describes the motivation for a biodiversity framing tied to this historical link: “in the 1980s, conservation biologists united and argued that biodiversity should be the focus of the discipline” which “rests on the value assumption that biodiversity is good and ought to be conserved”. This rationale, however, was not linked to any clear idea of what “biodiversity” means:

conservation biology as a discipline has expended a great deal of intellectual effort in articulating exactly what is its object of study and has settled on biodiversity as the answer. However, there is a debate concerning what biodiversity is….

Here, the stated rationale is that “biodiversity” is normative and is the focus of the discipline, but there is no reference to the pre-history discussions of a normatively relevant definition of biodiversity as variety.

The review of the development of the conservation biology, by Meine, Soule, and Noss. (2006), does trace some historical foundations. It documents the idea of a shift in thinking from individual species losses to loss of the diversity of life. This shift is described nicely in comparing two editions (1959 and 1987) of the same book (Matthiessen 1987)—where the 1987 version introduces new emphasis on the loss of “the diversity of life”. [ 2 ]

Sarkar (2017) notes that ecological diversity indices were largely ignored in the early history of conservation biology. In contrast, Meine, Soule, and Noss. (2006) frequently used the term “diversity”, This perhaps reflected co-author Noss’s (1990) much-cited paper characterising biodiversity as including composition, structure, and function, which echoes the range of “diversity” measures in ecology. The unlimited possibilities of such diversity measures may have contributed to the difficulty in finding agreement on a single definition of “biodiversity”. The conservation biology framing thus gains justification in embracing the prospect of “working-backwards”, with the challenge to define “biodiversity” to capture those aspects of biological/conservation normative value.

How then is “biodiversity” to be defined under these assumptions? The next two sections review the important discussions about the definition of biodiversity, and the later arguments that the definitional problems mean that the term “biodiversity” is counter-productive and should be abandoned.

“Biodiversity deflationism” emphasises the role of the biodiversity concept in conservation practice. Deflationists consider biodiversity as “what is conserved by the practice of conservation biology” (Sarkar 2002: 132). Unlike other framings of biodiversity, biodiversity is operationally defined, there is no semantic definition, just an output from the practice of conservation.

The practice of conservation biology should, within this view, be systematic conservation planning (Sarkar & Margules 2002). What is being conceptualised as biodiversity is revealed by this activity. This decision procedure involves using algorithms to identify a conservation area network; a conservation area that best optimises the interests of local stakeholders. Local stakeholders, people with an interest in that land, decide what features they want to prioritise. While stakeholder can have a wide range of interests in this land, they must include “biodiversity constituents” or “true surrogates” (Sarkar 2005, 2012). These describe the biotic features that the procedure maximises. “Biodiversity constituents” might appear to largely overlap with “biodiversity” in the sense of variety: a list of items, or measures of variety that describe biological items, which we aim to preserve. However, these items are not necessarily measuring biotic variety, as Sarkar includes sacred groves or the Monarch Butterfly Migration route as constituents of biodiversity. Sarkar stipulates that biodiversity constituents must satisfy the following conditions: they must be biological, variability of biotic features must be represented, taxonomic spread should be represented, these biotic features should not just be those of material use (Sarkar 2005; 2012). As such, there are adequacy conditions which guide what the procedure optimises and, as a result, conserves.

For proponents of biodiversity deflationism, there is no fact of the matter about what biodiversity is. Biodiversity is irrevocable local and tied to local values and interests in the natural environment. We can only infer backwards from what is preserved in the act of conservation to what convention tends to be described as biodiversity (Sarkar 2019). Therefore, biodiversity cannot play any role as a concept outside of the context of local conservation practice. This has an odd implication. Across biology biodiversity is used as concept within the science, both for conservation but for other sciences. Deflationists tend to dismiss biodiversity eliminativists, who want to ban the use of “biodiversity”, as too impractical as it is a common term in conservation (Sarkar 2019: 378). They, however, limit “biodiversity” to only conservation practice, claiming that scientific concepts of biodiversity are irrelevant (Sarkar 2019: 381). Biodiversity does not exist for the use of scientists in research. Thus, biodiversity conventionalists eliminate biodiversity from the context of scientific research and claim such research does not indicate what features we should preserve (see also the section on operationalizing biodiversity in the entry on conservation biology ).

While biodiversity has been accepted as a core goal of modern conservation science, there is some scepticism in the philosophical literature toward the utility of this concept. A series of philosophers have argued that the biodiversity concept is detrimental to environmental efforts (Maier 2012; Santana 2014, 2018; Morar, Toadvine, & Bohannan 2015). These arguments tend to coalesce around several points: that the biodiversity concept not operationalizable, biodiversity is not desirable, and that the concept obscures many of the values people have towards nature. The argument is that, either the concept cannot be used, or it may be used, but with recognition that it does not represent our ethical interest in the environment.

The belief that biodiversity cannot be adequately operationalized has appeared numerous times through the literature. Some argue that operationalizing biodiversity requires a “diversity” measure, or set of measures, both represent the concept of biodiversity and not be contradictory in its recommendations about what to conserve. Bryan Norton early on suggested that

strong arguments show that an index that captures all that is legitimately included as biodiversity is not possible. Biodiversity cannot be made a measurable quantity. (Norton 2008: 373)

This is because many of the different scientific measures for biodiversity are incommensurable, clashing with each other. For example: an area of possessing populations that are highly functionally distinct may be quite species poor. Some take the apparent incommensurability of biodiversity measures to show that measures should be used in context sensitive instances either relative to the development of conservation science or to the local interests of stakeholders (Koricheva & Siipi 2004; Sarkar 2005; Maclaurin & Sterelny 2008). An alternative considered is that we should narrow down the list of measures to that are most important according to some desiderata (Maclaurin & Sterelny 2008; Lean 2017; Meinard, Coq, & Schmid 2019).

Even if “biodiversity” was made to be tractable (in the sense used above), eliminativists are suspicious of biological diversity being regarded as valuable. Diversity across different biological arrangements is even argued to be undesirable. Maier points to diversity of parasites and diseases being undesirable (Maier 2012). Diversity sometimes reduces the value of taxa as the rarity of a species tends to increase its value (Santana 2014). Morar, Toadvine, and Bohannan (2015) explain this is because it is “not life’s variety but rather life itself” (2015: 24) that is valuable (without making reference to insurance and options values of variety). The perception of a mismatch between ethical interests in the environment and diversity is emphasised by all eliminativists.

Eliminativists believe “biodiversity” has mislead conservation, as the concept and term was designed to be exhaustive of human interests in the environment—and it cannot succeed in this task. The idea that biodiversity was designed to represent all human values of the environment appears in Maier’s work as “the biodiversity project”, Santana argues that biodiversity is just an intermediary for “ecological value”, and Morar, Toadvine, and Bohannan argue that biodiversity “does not exhaust what we value in the natural world” (2015: 24). Santana (2014) provides a clear presentation of this belief and uses it to argue that biodiversity is a misleading and unnecessary step in conservation planning. Biodiversity acts in conservation as an intermediary between all the ways we value the environment and the implementation of surrogate measures for these values, which are then used in conservation planning. Santana suggests we should remove the step of considering biodiversity and directly represent our values in the environment without considering diversity (see also SEP conservation biology entry)

This perspective differs from other frameworks for understanding biodiversity (including the focus on variety, originating in the pre-history of the term), which consider biodiversity as just one of several different conservation values which may trade off against each other (Faith 1995; Norton 2015; Lean 2017). One may choose to prioritise wilderness, or ecosystem services, over biodiversity and decision theoretic measures will be used to weight such considerations.

It is argued by some that biodiversity not only doesn’t represent all the ways the public values nature, it may also hinder the public’s engagement in nature. As a scientific “proxy” for natures value it is viewed as a dangerous case of scientism (Morar, Toadvine, & Bohannan 2015; Sarkar 2019). By having the “veneer of objectivity” it masks the normative dimension of conservation. The argument is that this can lead to an attitude of leave it to the scientists and shift the responsibility away from the policymakers and the public (Morar, Toadvine, & Bohannan 2015). This is interpreted as representing a dangerous impediment to the democratic dimension of conservation. This is regarded as an interesting question for the interface between conservation theory and public policy.

Eliminativism proposes that there are tensions in the use of the “biodiversity” concept, posing the idea that there is a mismatch between the scientific measures of biodiversity and the normative role it plays in conservation science. This perspective therefore contrasts strongly with the historical “variety” framing (above), where the scientific measure of biodiversity as variety, and its recognised value to humanity, is the source of normativity claims. [ 3 ] Eliminativists argue that, while it would be hard to remove “biodiversity” from use in conservation, this is necessary to allow for a clearer connection between humanities interests in the environment and conservation practice (also see the section on eliminating biodiversity in the entry on conservation biology ).

Sarkar (2019: 375) claims that “the term ”biodiversity“ and the associated concept(s)” arose along with the discipline of conservation biology. This accords with the deflationist and eliminativist perspectives that the “biodiversity story” began around 1985, with conservation biology guiding the conceptual development of “biodiversity”, including its definition and values. This narrative does not address the earlier conceptual history that had articulated normative value of living variation, and so it raises the need for comparisons with that “variationist” framing.

The SEP entry conservation biology provides some basis for comparisons, in exploring the idea that conservation biology is all about a still-undefined concept of “biodiversity”. In the entry’s section what is biodiversity? there are no citations of the early discussions from the 1970s, and so there is perhaps an under-appreciation of the early ideas of variety as a possible guide to resolving questions of definition. This relates to the interesting issues raised in this section about how the concept/definition of “biodiversity” is supposed to cope with the dis-benefits of some individual species. The challenge remains to recognise the possible useful distinction between biodiversity/variety and biospecifics (individual elements).

Consideration of the pre-history of “biodiversity” suggests that the conservation biology framing has adopted a story-line that is a disservice to systematics/taxonomy. As noted above, Sarkar (2017, 2019) follows his claim that the “biodiversity” term (and concept) were introduced in the context of the establishment of conservation biology, with the claim that

Subsequently, the term and the concept were embraced by other disciplines particularly by taxonomists…. as a conduit for funding that taxonomists wanted to exploit….

The pre-history, in contrast, reveals how the concept in fact arose through the work of systematists (e.g., Iltis 1972; Anonymous 1974), and was followed by calls by Wilson (1985) and others (see above) for more systematic efforts, in order to fill knowledge gaps (see also Lean, 2017).

The conservation biology framing highlights individual elements that are valuable, with less emphasis on variety. For example, Sarkar argues that conservation logically will focus on “those aspects of biotic variety that should be conserved. That does not necessarily include all of natural variety” (Sarkar 2019: 17). Sarkar’s example is revealing:

The human skin hosts thousands of microbial species though interpersonal variability is not as high as in the gut which hosts millions… Should we feel an imperative to conserve all the microbial diversity on the human skin or gut?

This sounds like a powerful example—who likes germs? The question in reality reveals an absence of consideration of the established benefits and values of variety itself. The gut microbial context is particularly revealing—over the past decade or so, reductions in an individuals’ variety of gut microbes (e.g., as measured using the PD biodiversity measure) is now associated with more than a dozen different human diseases. This biodiversity possibly provides a kind of insurance benefit in healthy individuals (see the link to “Phylogenetic Diversity and Human Health”, in Other Internet Resources ; for other philosophical issues related to microbial biodiversity, see Malaterre 2017).

A related conceptual disconnect is apparent also in Sarkar’s (2017) claim,

for a concept of biodiversity that can be used in practice for instance in the selection of conservation areas, richness was shown to be inadequate in the 1980s.

In contrast, variety or “richness” clearly is the desirable property of the set of conservation areas, and we use parts of the biodiversity “calculus” (see above), such as the complementarity of individual areas, in order to maximise this property of a nominated set. According to “variationists”, the concept of biodiversity as variety/richness is exactly what is needed to address the biodiversity crisis (Faith 2017).

Absence of recognition of the historical link between variety and normativity also suggests contrasts. The idea that “biodiversity” is the business of conservation biology, and that biodiversity is good, implies that,

if there is no adequate normative basis for biodiversity conservation, conservation biology becomes a dubious enterprise because its explicit purpose is the conservation of biodiversity.

The storyline is that conservation biology is normatively oriented, and so we have to find a definition of “biodiversity” that matches that normativity. In contrast, variationists would suggest the opposite: that “biodiversity” is normatively oriented, and then we have to find a “conservation biology” that addresses that normativity. Sarkar concludes that

how “biodiversity” is defined, that is, what the “constituents” of biodiversity are, depends on cultural choices about which natural values to endorse for conservation.

As noted above, the constituents of interest can include things like sacred groves, and processes like annual migration of Monarch butterflies (Sarkar 2019). Thus, this framing does not recognise biodiversity-as-variety, and its current benefit and normativity; instead, it looks for the elements that may be conserved with some normativity, and calls that “biodiversity”.

There seems to have been a logical development of arguments in the conservation framing—conservation biology was regarded as normatively all about “biodiversity”—a term interpreted as having no clear definition, and so to be defined by whatever conservation might normatively focus on—then arguments asserted that conservation focuses in practice on lots of things, and that this was a burden too great for the term. Not yet considered, in the development of philosophical arguments for the conservation biology framing, is the possibility that a miss-step was made right at the beginning—ignoring the preceding long history of “biodiversity” interpreted as variety, with current benefit to humanity, and normative import.

Eliminativists want to get rid of the term “biodiversity”, with the claim that this would allow for a clearer connection between humanity’s interests in the environment and conservation practice. But this is just one of at least three proposed fates for the problematic term “biodiversity”. Those advocating core biodiversity definitions and values based on variety (call them “variationists”, see also Burch-Brown and Archer 2017), might advocate adoption of this basic definition, with the claim that it not only accords best with the extinction crisis and core anthropocentric values (including insurance and investment), but also effectively allows trade-offs and synergies with humanity’s other interests.

A third pathway is discussed in the next section—where the fate of the problematic term “biodiversity” is not to be eliminativism, nor back-to-basics variationism, but is to be a kind of “holism”—“biodiversity” expanded in meaning to cover the whole range of “socio-ecological” or human-nature links.

The conservation biology framing interprets “biodiversity” as a term that is to capture everything we want to conserve. An emerging socio-ecological framing of biodiversity requires that the term take on a broader scope—it is to be made operational, not just for conservation, but more broadly for sustainability, encompassing the many ways that society and nature are inter-linked. While conservation biology has interpreted “biodiversity” as, from the start, all about society’s conservation values, the socio-ecological framing of biodiversity adopts a different narrative. Here, the claim is that, the term “biodiversity” started out with a too-narrow, strictly biological, interpretation, and now should be re-cast to better reflect, in different contexts, what society values about nature. The term “biodiversity” in fact appears to wear two different hats in the rationale for a socio-ecological framing: one of expectation and the other of disappointment. The expectation is that “biodiversity” is obliged to capture society’s various values and relationships with nature; the disappointment is based on the claim that in reality “biodiversity” has been too biotic and creates a human-nature dichotomy.

The roots of this framing are found in the idea that biodiversity must reflect society’s various environmental concerns. For example, the book, Defending Biodiversity (Newman, Varner, & Linquist 2017) focusses on philosophical issues about the value of “biodiversity”, because this is seen as the way to “throw a sufficiently large net over these many different flavours of environmentalism” (2017: 15). Similarly, Lele et al. (2018b) take as a starting point the idea that

The concept of biodiversity currently captures the core of naturalists’ concerns for the environment, subsuming earlier formulations such as wilderness or wildlife. (2018b: 7)

Two recent books summarise these perspectives ( Seeds of Change: Provocations for a New Research Agenda , Wyborn, Kalas, & Rust 2019 and Rethinking Environmentalism: Linking Justice, Sustainability, and Diversity , Lele et al. 2018a). In the first, Díaz (2019: 62) outlines an historical argument that “biodiversity” has been purely biological in focus, and therefore needs to be broadened to reflect human links:

The notion of biological diversity existed as a purely biological concept well before the word “biodiversity” emerged“ and ”Faced with the new challenge and desire to be useful to society,…. It is now clear that whilst “biodiversity” is about the biological realm, its crisis and potential solutions pertain to the social, cultural, economic and political realm….Broadening the concept of biodiversity—from a property of measurable biological systems to a socio-ecological boundary object.

Here, “biodiversity” history is presented as involving a post-1985 new-found desire to be useful to society, where, in response,

biological diversity scientists mustered the best tools they had: mathematical and statistical models and indices, which required a single and simple “currency”—the number of species…. (Díaz 2019; see also Sarkar 2019)

This claimed new awareness then sets up the call for a re-casting of “biodiversity”:

It is now clear that whilst “biodiversity” is about the biological realm, its crisis and potential solutions pertain to the social, cultural, economic and political realms. Therefore, diverse perspectives are needed in reframing biodiversity more broadly. Very few would contest this general statement…. (Díaz 2019: 62)

This claimed incontestability of the need for a biodiversity reframing is given support by an historical accounting that omits the rich history that had forged links to all those “realms” (see previous sections); anthropocentric insurance and investment values of biotic diversity (typically the number of species) were recognised in the context of the extinction crisis, and integrated in policy along with other needs of society. In contrast, the socio-ecological framing adopts a new historical accounting, where counting the number of species was simply a matter of mathematical and statistical models and indices, which then are found inadequate.

This new historical accounting omits the earlier history that justifies why biodiversity’s definition logically focusses on variety (or counting units). This omission props up the claim that even while “biodiversity” is largely biological, it is, at the same time, ill-defined and confusing. Redford and Mace (2018: 37) argue

The lack of clarity over the term simply adds another layer of confusion to what is already a complicated and interacting set of issues.

Mace (2019: 105) concludes

Looking back over the past 25 years—roughly the period that the Convention on Biological Diversity (CBD) has been in place and the term “biodiversity” has been in use—I conclude that it has become a confusing term… [ 4 ]

In the book, Rethinking Environmentalism: Linking Justice, Sustainability, and Diversity , Redford and Mace (2018) reinforce this interpretation of “biodiversity” as having only a recent history, with confusing definitions, and with little link to human concerns. This is seen as calling for the alternative socio-ecological framing, in which biodiversity conservation is seen as “inextricably linked to a living political discourse” so that a re-cast “biodiversity” can be defined “as including human beings” (2018: 33). Similar arguments are found in Koricheva and Siipi’s (2004) discussion of biodiversity as “a social and political construct”, compared to a purely scientific concept (see also the advocacy, by Meinard, Coq, & Schmid 2019, of “biodiversity practices” rather than “biodiversity”).

Pascual (2019) describes this framing as an “integrated socio-ecological” perspective where “biodiversity” is variously socially constructed. In this framing,

The ways we perceive and relate to biodiversity and make sense of it are influenced by collectively constructed and socially shared cognitive frameworks. (2019: 129)

Arguments for such a biodiversity re-casting have used the “people and nature” narrative (Díaz 2019). Mace (2014: 1559) describes the “people and nature” perspective as requiring

metrics that link nature to human well-being, explicitly identifying benefits needed and received by people … the science has moved fully away from a focus on species and protected areas and into a shared human nature environment, where the form, function, adaptability, and resilience provided by nature are valued most highly.

The rationale for rejecting the idea of “biodiversity” as a counting up of species (or other units) employs an argument that

biodiversity science can become quite reductionist and focussed on describing, defining, measuring and counting certain units of life. (Mace 2019: 105)

Mace concludes that

This aspect of biodiversity science to do with metrics has been important and influential, but curiously often somewhat disconnected from the global change and sustainability agenda. Important as it is this is, surely it is too narrow a focus for a biodiversity science that will support sustainability. (2019: 106)

This claim again highlights how the narrative in this socio-ecological framing sees “biodiversity” not only as obliged to capture sustainability, but also, in its present biological form, a disappointment in not being connected to humans.

Martin, McGuire, and Sullivan (2013: 125) similarly characterises “biodiversity” as problematical in being “distinct from other environmental phenomena, as well as from human activity”. They argue that such separation

may engender profoundly “unecological” thinking, by disassembling life’s entities both from each other and from the complex environmental contexts necessary for sustenance at all scales.

This dissatisfaction with counting-up units or items is echoed also in philosopher Elliot’s (2019) argument that “biodiversity” has failed to convince people to address environmental problems. He argues that that we need to “develop new conceptual schemes that link humans with their environments”, by

focusing less on specific items in the natural world that we want to maintain and more on developing resilient and sustainable systems that facilitate the myriad relationships between humans and nature. (2019: 68)

These perspectives within the socio-ecological framing suggest overlaps with the ideas of the conservation biology framing (though there appears to be little cross-citation). Significantly, both portray “biodiversity” as in need of some kind of re-casting, and both see the different ways in which society values nature as providing guidance about how we should interpret “biodiversity” in any given context. At the same time, core differences in the two framings remain: in one, “biodiversity” has a working biological definition, but is not connected to society’s values; in the other, “biodiversity” is connected to society’s (conservation) values, but we have no working definition.

A survey of the different perspectives about biodiversity’s definition and its values suggests new challenges for a coherent philosophy of biodiversity. For example, there has been little work recognising and reconciling two contrasting perspectives. In the “variationist” perspective, biodiversity-as-variety, is justifiably “biological”, and is normatively relevant; it enters broader sustainability practice through trade-offs and synergies with other needs of society. In the “socio-ecological” perspective, “biodiversity” is too “biological”, with no normativity, and it fails us if it is not re-cast to capture as a term all of the things that concern society within the global change and sustainability agenda.

There has been little cross-fertilisation among the three framings (variationist, conservation biology, and socio-ecological). The challenge ahead is to reconcile some strikingly different perspectives:

• “biodiversity” as biological (variation), and the benefit of variety as having normative importance,
• what is conserved as having normative importance, and the meaning of “biodiversity” obliged to capture all that,
• “biodiversity” as purely biological, and so needing a re-casting to gain normative status.

Challenges along the way will relate to the need to clarify distinctions between “biodiversity” as a property of a set, and “biodiversity” as a reference to that collection of units, where values of “biodiversity” then might refer to values of individual units or elements. For example, Pascual (2019: 129) used “nature” and “biodiversity” interchangeably, and this seems to have reflected a core interest in society’s values for “aspects” of biodiversity (not variety itself):

Valuation should therefore be about recognising and learning how to bridge distinct values of different people for different aspects of biodiversity.

When we start listing valued “aspects”, it is not surprising that this can be considered to be all-of-nature. However, we must ask: does this miss the opportunity to consider both the (often global) value of variety itself, and the (often local) value of favourite “aspects”?

A sense of history (and pre-history) may provide an important lens for synthesis across different perspectives. The IPBES (2019) Global Assessment reported that one million species may be at risk of extinction. Compare that to a report 40 years earlier, headlined, “The Threat to One Million Species” (Norman 1981). Significantly, both reports highlighted how the threat of extinctions is a potential loss of variety and future options for humanity. However, in the more recent reporting, this message is just one of many storylines in a complex, overwhelming, “biodiversity” narrative. This tangle of different storylines suggests that we now also face a “second biodiversity crisis” (Faith 2019), in which “biodiversity” has become a malleable term that is shaped and re-shaped to serve various scientific and policy agendas. The fate of “biodiversity” (the term) may have a lot to say about the fate of “biodiversity” (the variety of life).

A philosophy of “biodiversity” therefore still faces challenges at the most basic levels of definitions, values, and history. This calls out for synthesis of ideas, with equal attention to the fashionable new ideas and the (sometimes) unfashionable older ideas.

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• –––, 2006 [2016], “Ecology”, The Stanford Encyclopedia of Philosophy (Winter 2016 Edition), Edward N. Zalta (ed.), URL = < https://plato.stanford.edu/archives/win2016/entries/ecology/ >.
• –––, 2017, Approaches to Biodiversity , in Garson, Plutynski, and Sarkar 2017: ch. 3.
• –––, 2019, “What Should ‘Biodiversity’ Be?”, in Casetta, da Silva, and Vecchi 2019: 375–399. doi:10.1007/978-3-030-10991-2_18
• Sarkar, Sahotra and Chris Margules, 2002, “Operationalizing Biodiversity for Conservation Planning”, Journal of Biosciences , 27(4): 299–308. doi:10.1007/BF02704961
• Schroeder Doris and Balakrishna Pisupati, 2010, “Ethics, Justice and the Convention on Biological Diversity”, United Nations Environmental Program (UNEP). [ Schroeder and Pisupati 2010 available online ]
• Seddon, Nathalie, Georgina M. Mace, Shahid Naeem, Joseph A. Tobias, Alex L. Pigot, Rachel Cavanagh, David Mouillot, James Vause, and Matt Walpole, 2016, “Biodiversity in the Anthropocene: Prospects and Policy”, Proceedings of the Royal Society B: Biological Sciences , 283(1844): 20162094. doi:10.1098/rspb.2016.2094
• Swingland, Ian R., 2013, “Biodiversity, Definition Of”, in Levin 2013: vol. 1, pp. 399–410. doi:10.1016/B978-0-12-384719-5.00009-5
• WCED (World Commission on Environment and Development), 1987, Our Common Future , Oxford: Oxford University Press.
• Weikard, Hans-Peter, 2002, “Diversity Functions and the Value of Biodiversity”, Land Economics , 78(1): 20–27. doi:10.2307/3146920
• Weitzman, Martin L., 1992, “On Diversity”, The Quarterly Journal of Economics , 107(2): 363–405. doi:10.2307/2118476
• Westman, Walter E., 1977, “How Much Are Nature’s Services Worth?”, Science , 197(4307): 960–964. doi:10.1126/science.197.4307.960
• Wilson, Edward O., 1984, “Million-Year Histories: Species Diversity as an Ethical Goal”, Wilderness , 47 (Summer): 12–17.
• –––, 1985, “The Biological Diversity Crisis”, BioScience , 35(11): 700–706. doi:10.2307/1310051
• ––– (ed.), 1988, Biodiversity , Washington, DC: National Academies Press. doi:10.17226/989
• Wyborn, Carina, Nicole Kalas, and Niki A. Rust, 2019, Seeds of Change: Provocations for a New Research Agenda , Biodiversity Revisited Symposium Conference Proceedings, 11–13 September 2019, Vienna, Austria. doi:10.13140/RG.2.2.22170.59848/3

How to cite this entry . Preview the PDF version of this entry at the Friends of the SEP Society . Look up topics and thinkers related to this entry at the Internet Philosophy Ontology Project (InPhO). Enhanced bibliography for this entry at PhilPapers , with links to its database.

• Biodiversity , definition in the Glossary at the U.N./IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services).
• EDGE of Existence , program at the Zoological Society of London.
• Phylogenetic diversity and IPBES by Dan Faith.
• Phylogenetic Diversity and Human Health , by Dan Faith.

conservation biology | ecology | ethics: environmental

Acknowledgments

I thank Christopher Hunter Lean (Philosophy Department, University of Sydney) who provided discussions about key themes, draft text for the sections on deflationism and elimatativism, and a list of suggested references.

Copyright © 2021 by Daniel P. Faith < danfaith9 @ yahoo . com . au >

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• Biology Article
• Biodiversity

Biodiversity and its Types

Table of Contents

Types of Biodiversity

Importance of Biodiversity

Biodiversity in india, biodiversity definition.

“Biodiversity is the variation among living organisms from different sources including terrestrial, marine and desert ecosystems, and the ecological complexes of which they are a part.”

What is Biodiversity?

Biodiversity describes the richness and variety of life on earth. It is the most complex and important feature of our planet. Without biodiversity, life would not sustain.

The term biodiversity was coined in 1985. It is important in natural as well as artificial ecosystems. It deals with nature’s variety, the biosphere. It refers to variabilities among plants, animals and microorganism species.

Biodiversity includes the number of different organisms and their relative frequencies in an ecosystem. It also reflects the organization of organisms at different levels.

Biodiversity holds ecological and economic significance. It provides us with nourishment, housing, fuel, clothing and several other resources. It also extracts monetary benefits through tourism. Therefore, it is very important to have a good knowledge of biodiversity for a sustainable livelihood.

Also Read:  Flagship Species

There are the following three different types of biodiversity:

• Genetic Biodiversity
• Species Biodiversity
• Ecological Biodiversity

Species diversity  

Species diversity refers to the variety of different types of species found in a particular area. It is the biodiversity at the most basic level. It includes all the species ranging from plants to different microorganisms.

No two individuals of the same species are exactly similar. For example, humans show a lot of diversity among themselves. 

Genetic diversity

It refers to the variations among the genetic resources of the organisms. Every individual of a particular species differs from each other in their genetic constitution. That is why every human looks different from each other. Similarly, there are different varieties in the same species of rice, wheat, maize, barley, etc.

Ecological diversity  

An ecosystem is a collection of living and non-living organisms and their interaction with each other. Ecological biodiversity refers to the variations in the plant and animal species living together and connected by food chains and food webs.

It is the diversity observed among the different  ecosystems in a region. Diversity in different ecosystems like deserts, rainforests, mangroves, etc., include ecological diversity.

Also Read:  Biodiversity in Plants and Animals

Biodiversity and its maintenance are very important for sustaining life on earth. A few of the reasons explaining the importance of biodiversity are:

Ecological Stability

Every species has a specific role in an ecosystem. They capture and store energy and also produce and decompose organic matter. The ecosystem supports the services without which humans cannot survive. A diverse ecosystem is more productive and can withstand environmental stress.

Economic Importance

Biodiversity is a reservoir of resources for the manufacture of food, cosmetic products and pharmaceuticals.

Crops livestock, fishery, and forests are a rich sources of food.

Wild plants such as Cinchona and Foxglove plant are used for medicinal purposes.

Wood, fibres, perfumes, lubricants, rubber, resins, poison and cork are all derived from different plant species.

The national parks and sanctuaries are a source of tourism. They are a source of beauty and joy for many people.

Ethical Importance

All species have a right to exist. Humans should not cause their voluntary extinction. Biodiversity preserves different cultures and spiritual heritage. Therefore, it is very important to conserve biodiversity.

India is one of the most diverse nations in the world. It ranks ninth in terms of plant species richness. Two of the world’s 25 biodiversity hotspots are found in India. It is the origin of important crop species such as pigeon pea, eggplant, cucumber, cotton and sesame. India is also a centre of various domesticated species such as millets, cereals, legumes, vegetables, medicinal and aromatic crops, etc.

India is equally diverse in its faunal wealth. There are about 91000 animal species found here.

However, diversity is depleting at a drastic rate and various programmes on biodiversity conservation are being launched to conserve nature.

Also read: Ecology

Frequently Asked Questions

What is biodiversity, what are the different types of biodiversity.

The three types of biodiversity are:

• Species Diversity
• Genetic Diversity
• Ecological Diversity

What is ecological diversity?

What is the role of biodiversity in maintaining environmental balance, what is the importance of biodiversity.

• Maintaining the balance of the ecosystem: Recycling and storage of nutrients, combating pollution, stabilizing climate, protecting water resources, forming and protecting soil and maintaining eco-balance
• Provision of biological resources: Provision of medicines and pharmaceuticals, food for the human population and animals, ornamental plants, wood products, breeding stock and diversity of species, ecosystems and genes.
• Social benefits: Recreation and tourism, cultural value and education and research.

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Biodiversity and Its Conservation: Importance, Threats, Strategies

• Editor Desk
• June 15, 2023
• Biodiversity

Biodiversity , the variety of life on Earth, encompasses all forms of living organisms, including plants, animals, and microorganisms. It is the result of billions of years of evolution and plays a vital role in maintaining the health and balance of ecosystems. However, due to various human activities, biodiversity is facing unprecedented threats, making its conservation crucial for the survival of species and the sustainability of our planet. In this article, we will explore the significance of biodiversity, the current threats it faces, and the strategies and approaches employed in its conservation.

I. Importance of Biodiversity

Biodiversity is essential for the functioning of ecosystems and provides numerous benefits to humanity. It ensures ecological balance by regulating various ecological processes, such as nutrient cycling, water purification, and pollination. Biodiversity also contributes to the production of food, medicines, and raw materials, and supports cultural and aesthetic values. Furthermore, it enhances resilience to environmental changes and helps mitigate the impacts of climate change .

II. Threats to Biodiversity

• Habitat Loss: The destruction, fragmentation, and degradation of habitats due to deforestation, urbanization, and land conversion for agriculture and infrastructure development.
• Climate Change: Rising temperatures, changing precipitation patterns, and extreme weather events disrupt ecosystems, altering species’ distribution and abundance.
• Invasive Species: Non-native species introduced to new environments can outcompete native species, leading to their decline or extinction.
• Pollution: Pollution from various sources, such as industrial activities and agricultural runoff, can contaminate ecosystems, affecting biodiversity.
• Overexploitation: Unsustainable hunting, fishing, and harvesting practices can deplete populations of species, driving them towards extinction.

III. Conservation Strategies

• Protected Areas: Establishing and effectively managing protected areas, such as national parks and wildlife reserves, to safeguard habitats and species.
• Habitat Restoration: Rehabilitating degraded ecosystems by reforesting, wetland restoration, and implementing sustainable land management practices.
• Species Conservation: Implementing measures like captive breeding, habitat protection, and anti-poaching efforts to safeguard endangered species.
• Sustainable Practices: Encouraging sustainable agriculture, fisheries, forestry, and promoting responsible consumption to minimize negative impacts on biodiversity.
• Awareness and Education: Raising public awareness about the value of biodiversity and the need for its conservation through education and outreach programs.

Key Takeaways:

Conserving biodiversity is vital for sustaining life on Earth and ensuring a healthy and prosperous future. By understanding the importance of biodiversity, identifying the threats it faces, and implementing effective conservation strategies, we can work towards preserving our natural heritage and creating a more sustainable planet. It requires collective efforts from individuals, communities, governments, and international organizations to protect and restore biodiversity for the benefit of current and future generations. Let us embrace our responsibility as custodians of Earth’s biodiversity and take action to secure a thriving and diverse planet.

FAQs about Biodiversity and its Conservation:

What is biodiversity.

Biodiversity refers to the variety of life on Earth, including all living organisms, from plants and animals to microorganisms. It encompasses genetic, species, and ecosystem diversity.

Why is biodiversity important?

Biodiversity is crucial for the health and balance of ecosystems. It provides various ecosystem services like nutrient cycling, pollination, and water purification. Biodiversity also contributes to food production , medicine development, and supports cultural and aesthetic values.

What are the main threats to biodiversity?

The main threats to biodiversity include habitat loss due to deforestation and land conversion, climate change, invasive species, pollution, and overexploitation of natural resources.

What are protected areas?

Protected areas are designated regions, such as national parks, wildlife reserves, and marine sanctuaries, created to conserve biodiversity and preserve natural habitats. They often have legal protections to limit human activities that could harm the environment .

What is habitat restoration?

Habitat restoration involves the process of rehabilitating degraded ecosystems by restoring their natural features and functions. It may include activities like reforestation, wetland restoration, and implementing sustainable land management practices.

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EU’s Ambitious Goal: Restoring 20% of Lands and Waters by 2030

• November 18, 2023

Biosphere Reserve: Preserving South India’s Rich Biodiversity

• November 17, 2023

E. O. Wilson and Biodiversity

Everyone talks about biodiversity these days, but an entomologist just might be its fiercest advocate.

Biodiversity has become a leading area of concern in many fields pertaining to the environment, including conservation, ecology, and environmental policy, particularly under climate change. Threats to biodiversity are abundant, and as the world warms, there is an increasing need to protect species and their habitats.

The rise of the term “biodiversity” to prominence can be attributed to the entomologist E. O. Wilson, who was one of the first scientists to describe the biodiversity crisis in the 1980s and work to find solutions to it. He explored the meaning of the word in a 1996 interview with The American Biology Teacher :

Biologists define biodiversity in the broadest sense as meaning all of the variety of life-from the different genes at the same chromosome position within populations, up through different species of organisms, on up to different aggregations of species in ecosystems…It is very important to study each one in turn and to understand fully how they are related to each other: the genes, the species and the ecosystems.

A taxonomist and naturalist by training, Wilson became a scientific generalist, unlike most scientists, who specialize narrowly. His work unites biology, evolution, and ecology. He believes that the biodiversity crisis requires advocacy as well as research, and he spends time educating the public on the nature of the problem.

The rate of extinction today is estimated to be a thousand times what it should be under natural selection. If this continues, Wilson has predicted , one-fifth of all plant and animal species will be either extinct or endangered by 2030.

Wilson’s germinal research on ant communities has focused on finding new species and detailing how they interact with one another and their environment. His approach to community biology has led to the development of the field of sociobiology, the study of species interactions, which continues to influence how species are studied and protected today. Wilson’s theories on population interactions are used across biology, evolution, and even psychology.

Wilson is also known for his ideas to protect biodiversity . He has written extensively about the half-earth strategy , a plan to protect half of the Earth’s ecosystems.

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Wilson not only advocates protecting species now, he also is a leading proponent of the impacts that biodiversity loss could have in the future. As he explains in the interview with Neil Campbell, “The reason we should study and maintain biodiversity is the great benefit that it can provide. Once lost, the species and its library of genetic information, with potential importance to the ecosystem, is gone forever and cannot be retrieved.”

But ever a naturalist at heart, his passion extends beyond research. He concludes in his article, “To know this world is to gain a proprietary attachment to it. To know it well is to love and take responsibility for it .”

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biodiversity

Definition of biodiversity

Did you know.

Biodiversity may become the rallying call for the next decade, wrote David Wake in the journal Science in 1989. Indeed, biodiversity is a word you're likely to encounter in writing about ecology and the environment today. But when Wake used it, "biodiversity" was still a relatively new addition to the English language, having first appeared in writing in the mid-1980s. Of course, the roots of biodiversity are much older. It evolved from a commingling of the descendants of the Greek noun bios, which means "mode of life," and the Latin verb divertere, which means "to turn aside" or "to go different ways."

Examples of biodiversity in a Sentence

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'biodiversity.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

bio- + diversity

1985, in the meaning defined above

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Dictionary Entries Near biodiversity

biodigester

Cite this Entry

“Biodiversity.” Merriam-Webster.com Dictionary , Merriam-Webster, https://www.merriam-webster.com/dictionary/biodiversity. Accessed 9 Apr. 2024.

Kids Definition

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Essay on Conservation of Biodiversity for Students and Children

500+ words essay on conservation of biodiversity.

Conservation of biodiversity is vital for maintaining the Earth’s environment and sustaining life on the planet. There are a number of ways in which the richness of biodiversity helps in maintaining the ecological system. Conservation of biodiversity is important for the survival of living beings on Earth. Hence, a lot of emphases is being given on the conservation of biodiversity these days.

The Extinction in Biodiversity

Due to human activities, numerous varieties of animals go extinct each year. Western Black Rhinoceros, Dodo, Tasmanian tiger, Golden Toad, Woolly Mammoth, Caribbean Monk Seal, Ivory-billed Woodpecker, and Japanese Sea Lion are some of the species of animals that have gone extinct.

Lemur, Mountain Gorilla, Vaquita, Sea Turtles, Amur Leopard, and Tiger are some of the species that are on the verge of extinction. Apart from these many species of plants and trees including Lepidodendron, Araucaria Mirabilis, Wood Cycad and Kokia Cookie have gone extinct and many species are endangered.

Need to Conserve Biodiversity

Earth is a beautiful planet which has given us many things which occur naturally. Natural resources, rivers, valleys , oceans, different species of animals and beautiful varieties of plants and trees are among some of these.

In today’s world, we are busy developing our surroundings and spoiling our beautiful environment. Today, we have exploited most of the things that were available abundantly in nature. Thus, there arises a need to conserve these natural things. Among other things, there is a serious need for the conservation of biodiversity.

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Importance of Conservation of Biodiversity

Conservation of biodiversity is important for many reasons. Here are some of the main reasons to conserve biodiversity:

• Process of Food Chain: Different species of animals and plants serve as the source of food for other animals and living organisms. Thus, conserving biodiversity help to keep the food chain among the living organisms.
• Nutritional Needs: The decline in the variety of plants and animals would mean the decline in the variety of food we eat. So, this is likely to result in nutritional deficiencies.
• Cleaner Air: Plants and trees have a greater ability to purify the air and keep the atmosphere clean. As there is a decrease in the number and types of trees and plants, it impacts the quality of air in a negative way.
• Better Cultivation of Crops:   Fertility of soil is maintained by many insects, organisms and microorganisms work on different levels. So we have to maintain the level of microorganism which is better for the cultivation of crops.
• For Medical Reason s: For making different medicines many species of trees and plants are used so as to cure various diseases.

Methods to Conserve Biodiversity

Methods that can help in the conservation of biodiversity are

• Control Population: The greater the population the higher the needs which would result in further exploitation of flora and fauna and decline in biodiversity. For the conservation of biodiversity, we have to control the human population and allow other species of plants and animals to replenish on our planet.
• Control Pollution: The changing climate, deteriorating air quality and the growing amount of pollution on land and water bodies are leading to different types of diseases in many. It is essential to reduce the activities leading to pollution so as to conserve biodiversity.
• Reduce Deforestation: Due to deforestation, there is the loss of habitat. Due to this reason, wild animals are unable to survive in the new environment and die.
• Avoid Wastage: We need to understand that natural resources are not only essential for us but are also vital for the survival of other species. We must thus utilize only as much as we require them so that these remain available in abundance in nature for future use.
• Spread Awareness: Apart from this, one of the best methods to conserve biodiversity is by spreading awareness. The government can do so at a bigger level. While we can spread awareness by word of mouth and through social media.

Conservation of biodiversity is of utmost importance. We must all make efforts to conserve biodiversity rather than contributing towards its declination. Thus, the richness of biodiversity is essential for the survival of living beings on Earth.

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John Barth, innovative postmodernist novelist, dies at 93

The Associated Press

ANNAPOLIS, Md. — John Barth, the playfully erudite author whose darkly comic and complicated novels revolved around the art of literature and launched countless debates over the art of fiction, died Tuesday. He was 93.

Johns Hopkins University, where Barth was an emeritus professor of English and creative writing, confirmed his death in a statement.

Along with William Gass , Stanley Elkin and other peers, Barth was part of a wave of writers in the 1960s who challenged standards of language and plot. The author of 20 books including "Giles Goat-Boy" and "The Sot-Weed Factor," Barth was a college writing instructor who advocated for postmodernism to literature, saying old forms were used up and new approaches were needed.

Barth's passion for literary theory and his innovative but complicated novels made him a writer's writer. Barth said he felt like Scheherazade in "The Thousand and One Nights," desperately trying to survive by creating literature.

He created a best-seller in 1966 with "Giles Goat-Boy," which turned a college campus into a microcosm of a world threatened by the Cold War, and made a hero of a character who is part goat.

The following year, he wrote a postmodern manifesto, "The Literature of Exhaustion," which argued that the traditional novel suffered from a "used-upness of certain forms." The influential Atlantic Monthly essay described the postmodern writer as one who "confronts an intellectual dead end and employs it against itself to accomplish new human work."

He clarified in another essay 13 years later, "The Literature of Replenishment," that he didn't mean the novel was dead — just sorely in need of a new approach.

Book News & Features

The enduring life of lit mags: we'll always have (the) paris (review).

"I like to remind misreaders of my earlier essay that written literature is in fact about 4,500 years old (give or take a few centuries depending on one's definition of literature), but that we have no way of knowing whether 4,500 years constitutes senility, maturity, youth, or mere infancy," Barth wrote.

Barth frequently explored the relationship between storyteller and audience in parodies and satire. He said he was inspired by "The Thousand and One Nights," which he discovered while working in the classics library of Johns Hopkins University.

"It is a quixotic high-wire act to hope, at this late hour of the century, to write literary material and contend with declining readership and a publishing world where businesses are owned by other businesses," Barth told The Associated Press in 1991.

Barth pursued jazz at the Juilliard School of Music in New York, but found he didn't have a great talent for music, and so turned to creative writing, a craft he taught at Penn State University, SUNY Buffalo, Boston University and Johns Hopkins.

His first novel, "The Floating Opera," was nominated for a National Book Award. He was nominated again for a 1968 short story collection, "Lost in the Funhouse," and won in 1973 for "Chimera," three short novels focused on myth.

His breakthrough work was 1960's "The Sot-Weed Factor," a parody of historical fiction with a multitude of plot twists and ribald hijinks. The sprawling, picaresque story uses 18th-century literary conventions to chronicle the adventures of Ebenezer Cooke, who takes possession of a tobacco farm in Maryland.

Here's how to set your reading goals and read more books in 2024

Barth was born on Maryland's Eastern Shore and set many of his works there. Both his 1982 "Sabbatical: A Romance" and his 1987 "The Tidewater Tales" feature couples sailing on the Chesapeake Bay.

Barth also challenged literary conventions in his 1979 epistolary novel "Letters," in which characters from his first six novels wrote to each other, and he inserted himself as a character as well.

"My ideal postmodernist author neither merely repudiates nor merely imitates either his twentieth-century modernist parents or his nineteenth-century premodernist grandparents. He has the first half of our century under his belt, but not on his back."

Barth kept writing in the 21st century.

In 2008, he published "The Development," a collection of short stories about retirees in a gated community. "Final Fridays," published in 2012, was his third collection of non-fiction essays.

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Guest Essay

I’m an Economist. Don’t Worry. Be Happy.

By Justin Wolfers

Dr. Wolfers is a professor of economics and public policy at the University of Michigan and a host of the “Think Like an Economist” podcast.

I, too, know that flash of resentment when grocery store prices feel as if they don’t make sense. I hate the fact that a small treat feels less like an earned indulgence and more like financial folly. And I’m concerned about my kids now that house prices look like telephone numbers.

But I breathe through it. And I remind myself of the useful perspective that my training as an economist should bring. Sometimes it helps, so I want to share it with you.

Simple economic logic suggests that neither your well-being nor mine depends on the absolute magnitude of the numbers on a price sticker.

To see this, imagine falling asleep and waking up years later to discover that every price tag has an extra zero on it. A gumball costs $2.50 instead of a quarter; the dollar store is the $10 store; and a coffee is $50. The $10 bill in your wallet is now $100; and your bank statement has transformed $800 of savings into $8,000.

Importantly, the price that matters most to you — your hourly pay rate — is also 10 times as high.

What has actually changed in this new world of inflated price tags? The world has a lot more zeros in it, but nothing has really changed.

That’s because the currency that really matters is how many hours you have to work to afford your groceries, a small treat or a home, and none of these real trade-offs have changed.

This fairy tale — with some poetic license — is roughly the story of our recent inflation. The pandemic-fueled inflationary impulse didn’t add an extra zero to every price tag, but it did something similar.

The same inflationary forces that pushed these prices higher have also pushed wages to be 22 percent higher than on the eve of the pandemic. Official statistics show that the stuff that a typical American buys now costs 20 percent more over the same period. Some prices rose a little more, some a little less, but they all roughly rose in parallel.

It follows that the typical worker can now afford 2 percent more stuff. That doesn’t sound like a lot, but it’s a faster rate of improvement than the average rate of real wage growth over the past few decades .

Of course, those are population averages, and they may not reflect your reality. Some folks really are struggling. But in my experience, many folks feel that they’re falling behind, even when a careful analysis of the numbers suggests they’re not.

That’s because real people — and yes, even professional economists — tend to process the parallel rise of prices and wages in quite different ways. In brief, researchers have found that we tend to internalize the gains caused by inflation and externalize the losses. Those different processes yield different emotional responses.

Let’s start with higher prices. Sticker shock hurts. Even as someone who closely studies the inflation statistics, I’m still often surprised by higher prices. They feel unfair. They undermine my spending power, and my sense of control and order.

But in reality, higher prices are only the first act of the inflationary play. It’s a play that economists have seen before. In episode after episode, surges in prices have led to — or been preceded by — a proportional surge in wages.

Even though wages tend to rise hand in hand with prices, we tell ourselves a different story, in which the wage increases we get have nothing to do with price increases that cause them.

I know that when I ripped open my annual review letter and learned that I had gotten a larger raise than normal, it felt good. For a moment, I believed that my boss had really seen me and finally valued my contribution.

But then my economist brain took over, and slowly it sunk in that my raise wasn’t a reward for hard work, but rather a cost-of-living adjustment.

Internalizing the gain and externalizing the cost of inflation protects you from this deflating realization. But it also distorts your sense of reality.

The reason so many Americans feel that inflation is stealing their purchasing power is that they give themselves unearned credit for the offsetting wage increases that actually restore it.

Those who remember the Great Inflation of the ’60s, ’70s and early ’80s have lived through many cycles of prices rising and wages following. They understand the deal: Inflation makes life more difficult for a bit, but you’re only ever one cost-of-living adjustment away from catching up.

But younger folks — anyone under 60 — never experienced sustained inflation rates greater than 5 percent in their adult lives. And I think this explains why they’re so angry about today’s inflation.

They haven’t seen this play before, and so they don’t know that when Act I involves higher prices, Act II usually sees wages rising to catch up. If you didn’t know there was an Act II coming, you might leave the theater at intermission thinking you just saw a show about big corporations exploiting a pandemic to take your slice of the economic pie.

By this telling, decades of low inflation have left several generations ill equipped to deal with its return.

While older Americans understand that the pain of inflation is transitory, younger folks aren’t so sure. Inflation is a lot scarier when you fear that today’s price rises will permanently undermine your ability to make ends meet.

Perhaps this explains why the recent moderate burst of inflation has created seemingly more anxiety than previous inflationary episodes.

More generally, being an economist makes me an optimist. Social media is awash with (false) claims that we’re in a “ silent depression ,” and those who want to make America great again are certain it was once so much better.

But in reality, our economy this year is larger, more productive and will yield higher average incomes than in any prior year on record in American history. And because the United States is the world’s richest major economy, we can now say that we are almost certainly part of the richest large society in its richest year in the history of humanity.

The income of the average American will double approximately every 39 years. And so when my kids are my age, average income will be roughly double what it is today. Far from being fearful for my kids, I’m envious of the extraordinary riches their generation will enjoy.

Psychologists describe anxiety disorders as occurring when the panic you feel is out of proportion to the danger you face. By this definition, we’re in the midst of a macroeconomic anxiety attack.

And so the advice I give as an economist mirrors what I would give were I your therapist: Breathe through that anxiety, and remember that this, too, shall pass.

Justin Wolfers is a professor of economics and public policy at the University of Michigan and a host of the “Think Like an Economist” podcast.

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