Biodiversity
Explore the diversity of wildlife across the planet. What are species threatened with? What can we do to prevent biodiversity loss?
Most of our work on Our World in Data focuses on data and research on human well-being and prosperity.
But we are just one of many species on Earth, and our demand for resources – land, water, food, and shelter – shapes the environment for other wildlife too.
For millennia, humans have been reshaping ecosystems, directly through competition and hunting of other animals, and indirectly through deforestation and land use changes for agriculture.
You can find all our data, visualizations, and writing related to biodiversity on this page. It aims to provide context on how biodiversity has changed in the past; the state of wildlife today; and how we can use this knowledge to build a future path where humans and other species can thrive on our shared planet.
Key insights on Biodiversity
On average, there has been a large decline across tens of thousands of wildlife populations since 1970
One of the most widely-quoted, but misunderstood, metrics on biodiversity is the Living Planet Index.
The Living Planet Index tries to summarize the average change in population size of tens of thousands of studied animal populations. It distills this change into a single number.
It's important to note that this data is not globally representative: some regions have much more data available than others. Biodiversity data is much more limited in the tropics, for example.
What it reports is the average decline in animal population sizes since 1970. This does not tell us the:
- Number of species lost;
- Number of populations or individuals that have been lost;
- Number or percentage of species or populations that are declining;
- Number of extinctions.
Since 1970, then, the size of animal populations for which data is available have declined by 73%, on average. The decline for some populations is much larger; for some, it’s much smaller. And, in fact, many populations have been increasing in size. We cover this in the next key insight.
Living Planet Index: what does it really mean?
The Living Planet Index is the biodiversity metric that always claims the headlines. It’s often misinterpreted. How should we understand it?
What you should know about this data
- The Living Planet Project – which produces the Living Planet Index – is led by the Zoological Society of London (ZSL) and World Wildlife Fund (WWF)..1
- Every two years, a new Living Planet Index report is published. This presents the latest high-quality data we have on animal populations, but also increases in global coverage with every new release.
- The underlying data included in the Living Planet Index comes from a combination of published scientific articles, online databases, and government reports.
- The Living Planet Index aggregates observations on changes in population size, and similar metrics, across tens of thousands of animal populations. Its 2024 report included figures across 34,000 wildlife populations. This captures everything from frogs to elephant species, rhinos to owls, from every continent on Earth. But even 34,000 populations are only a small fraction of the world’s wildlife.
- This data is not globally representative: some regions have much more data available than others. Biodiversity data is much more limited in the tropics, for example.
- The Living Planet Index only includes figures on vertebrate species – mammals, birds, fish, reptiles, and amphibians. It does not include insects, corals, fungi, or plants.
- Its final index is the average change in population size across all of the included animal populations. This figure is not representative of every population and is sensitive to outliers.2
Not all animal populations are in decline; around half have increasing numbers
The Living Planet Index reports that there has been a large average decline across more than 34,000 animal populations.
But, reducing the state of global biodiversity into a single figure is a problem. It hides a huge diversity of changes in animal populations within the dataset.
The Living Planet Project also shows us what percentage of studied populations have increased, decreased, and remained stable since 1970.
Almost half of these animal populations have remained stable or increased. This is shown in the chart.
Understanding the broad range of changes in populations is crucial if we’re to stop biodiversity loss – we need to know that not all animal populations are declining. We need to also know which populations are doing well and why they’re doing well.
How the Living Planet project helps us understand changes in the world’s wildlife
Beneath the popular index, the Living Planet database helps us understand where and what animals are deeply threatened, and what animals are thriving.
What you should know about this data
- The Living Planet Project – which produces the Living Planet Index – is led by the Zoological Society of London (ZSL) and World Wildlife Fund (WWF)..1
- Every two years, a new Living Planet Index report is published. This presents the latest high-quality data we have on animal populations, but also increases in global coverage with every new release.
- The underlying data included in the Living Planet Index comes from a combination of published scientific articles, online databases, and government reports.
- The Living Planet Index aggregates observations on changes in population size, and similar metrics, across tens of thousands of animal populations. Its 2024 report included figures across 34,000 wildlife populations. This captures everything from frogs to elephant species, rhinos to owls, from every continent on Earth. But even 34,000 populations are only a small fraction of the world’s wildlife.
- This data is not globally representative: some regions have much more data available than others. Biodiversity data is much more limited in the tropics, for example.
- The Living Planet Index only includes figures on vertebrate species – mammals, birds, fish, reptiles, and amphibians. It does not include insects, corals, fungi, or plants.
- Its final index is the average change in population size across all of the included animal populations. This figure is not representative of every population and is sensitive to outliers.2
Wild mammals have declined by 85% since the rise of humans
A diverse range of mammals once roamed the planet. This changed quickly and dramatically with the rising number of humans over the course of the last 100,000 years.
Over this period, wild terrestrial mammal biomass has declined by an estimated 85%. This is shown in the chart.
This looks at the change in wild mammals on the basis of biomass. This means that each animal is measured in tonnes of carbon that it holds. This is a function of its body mass.
In an extended period between 50,000 to 10,000 years ago, hundreds of the world’s largest mammals were wiped out. This is called the Quaternary megafauna extinction event.
Humans were the main driver of this, killing off species through overhunting and changes to their habitats. What’s staggering is how few humans were alive at this time: fewer than 5 million people across the world.
Since then, wild mammals have continued to decline. A lot of this has been driven by the expansion of human agriculture into wild habitats.
But, the future can be very different. We have the opportunity to restore wild mammals by reducing hunting and poaching, and cutting the amount of land that we use for farming.
Wild mammals have declined by 85% since the rise of humans, but there is a possible future where they flourish
Wild mammal biomass has declined by 85% since the rise of humans. But we can turn things around by reducing the amount of land we use for agriculture.
What you should know about this data
- These estimates come from a combination of studies:
- Only terrestrial mammals are included in these estimates. Marine mammals, such as whales, are excluded.
- These estimates compare mammals on the basis of biomass. This means that each animal is measured in tonnes of carbon that it holds. This is a function of its body mass.
- To calculate the biomass of a taxonomic group, the researchers multiply the carbon stock for a single organism by the number of individuals in that group. In humans, for example, they would calculate the average carbon quantity of a person (about 15%) and multiply it by the human population.
- These figures are approximate and come with significant uncertainty, for two key reasons:
Wild mammals make up only a few percent of the world’s mammals
In the chart, we see the distribution of mammals on Earth.3 These estimates compare mammals on the basis of biomass. This means that each animal is measured in tonnes of carbon that it holds. This is a function of its body mass. Each rectangle represents one million tonnes of carbon.
Wild mammals make up just 4% of global mammal biomass. This includes marine and land-based mammals.
The other 96% is humans and our livestock.
The dominance of humans is clear. Alone, we account for around one-third of mammal biomass. Almost ten times greater than wild mammals.
Our livestock then accounts for almost two-thirds. Cattle weigh almost ten times as much as all wild mammals combined. The biomass of all of the world’s wild mammals is about the same as our sheep.
Poultry is not included here. But for birds, the distribution is similar: poultry biomass is more than twice that of wild birds.
Wild mammals make up only a few percent of the world’s mammals
Livestock make up 62% of the world’s mammal biomass; humans account for 34%; and wild mammals are just 4%.
What you should know about this data
- This data comes from the study of biomass distribution on Earth by researchers Yinon Bar-On, Rob Phillips, and Ron Milo, published in the Proceedings of the National Academy of Sciences.3
- These estimates compare mammals on the basis of biomass. This means that each animal is measured in tonnes of carbon that it holds. This is a function of its body mass.
- To calculate the biomass of a taxonomic group, the researchers multiplied the carbon stock for a single organism by the number of individuals in that group. In humans, for example, they calculate the average carbon quantity of a person and multiply by the human population. If you want to quickly estimate your carbon biomass: calculate 15% of your weight.
- These figures are approximate and come with significant uncertainty because the total number of wild mammals is highly uncertain.
Thanks to conservation efforts, some wild mammals are making a comeback
We have already seen that many animal populations have increased in the last decades.
Mammals in Europe are a prime example. Many of the region’s iconic mammal species – such as the Eurasian beaver, European bison, and brown bear – have been making a return.
In the chart, we see the average change in the population size of several mammal species in Europe. The studied time span differs from animal to animal, as the chart shows.
For example between 1960 and 2016, populations of brown bears increased by an average of 44%. Between 1977 and 2016, populations of Eurasian otters increased by an average of 300%.
Conservation efforts have played an important role in the return of these mammals, but it is not the only reason for this positive development. One important change is that the rise in agricultural productivity made it possible that agricultural land has declined across Europe, giving more habitat back to wildlife. Countries brought in hunting quotas or even complete bans on hunting. And some species – such as the European bison – were brought back through well-managed re-introduction programs.
Wild mammals are making a comeback in Europe thanks to conservation efforts
Hunting and habitat loss drove many large mammals in Europe close to extinction. New data shows us that many of the continent’s mammal populations are flourishing again.
What you should know about this data
- This data comes from the Wildlife Comeback Report 2022. This is published by a coalition of conservation organizations, including the Zoological Society of London; Birdlife International; and Rewilding Europe.4
- The dataset aggregates multiple studies of animal populations for each species. For example, 98 populations are included in the final figures for Eurasian beavers.
- Researchers calculate the averagerelative change in population size across all of the studied populations of a given species. The final figure does not tell us the total change in populations across Europe.
- Not every species in Europe is increasing in numbers. The underlying report focuses on a selection of mammal species that have made a comeback in recent decades. Many of those that are not shown might still be in decline, or only have stable population numbers.
Research & Writing
Wild mammals have declined by 85% since the rise of humans, but there is a possible future where they flourish
Wild mammal biomass has declined by 85% since the rise of humans. But we can turn things around by reducing the amount of land we use for agriculture.
Wild mammals are making a comeback in Europe thanks to conservation efforts
Hunting and habitat loss drove many large mammals in Europe close to extinction. New data shows us that many of the continent’s mammal populations are flourishing again.
Living Planet Index
The 2024 Living Planet Index reports a 73% average decline in wildlife populations — what’s changed since the last report?
Living Planet Index: what does it really mean?
How the Living Planet project helps us understand how the world’s wildlife is changing
How did the Living Planet Index change in different world regions?
FAQs on the Living Planet Index
Mammals
Extinctions
Other articles on Biodiversity
How much of the world’s food production is dependent on pollinators?
To protect the world’s wildlife we must improve crop yields – especially across Africa
Humans make up just 0.01% of Earth’s life – what’s the rest?
Oceans, land, and deep subsurface: how is life distributed across environments?
How many species are there?
All charts
Living Planet Index
Living Planet Index by region
Number of described species
Number of whales killed globally per decade
Red List Index
African elephant carcass ratio
Annual fish catch relative to mean catch
Annual fish catch relative to mean catch by region
Aquaculture production
Black rhino population
Capture fishery production
Change in bird populations in the EU
Changes in UK butterfly populations
Countries have a budget for invasive alien species management
Countries that are party to the Nagoya Protocol
Countries that have legislative measures reported to the Access and Benefit-Sharing Clearing-House
Countries with more than 25 species at risk of losing more than 25% of their habitat by 2050
Cumulative first records of alien species
Day of the year with peak cherry tree blossom in Kyoto, Japan
Drivers of recovery in European bird populations
Endemic amphibian species
Endemic bird species
Endemic freshwater crab species
Endemic mammal species
Endemic reef-forming coral species
Endemic shark and ray species
Fish and seafood production
Fish catch in the United Kingdom
Fish discards
Fish stocks and fishing intensity by group
Fish stocks and fishing intensity by region
Fishing intensity
Fishing intensity by region
Five centuries of cod catches in Eastern Canada
Global aquaculture production and wild fish used for animal feed
Global biomass vs. abundance of taxa
Global first records of non-native species
Global wildlife exports
Health of fish stocks by fish group
Health of fish stocks by region
Indian rhino population
Javan rhino population
Local animal breeds with conserved genetic material
Member countries of the International Treaty on Plant Genetic Resources for Food and Agriculture
Mountain Green Cover Index
National biodiversity strategy and action plan targets align with Aichi Biodiversity Target 9
National progress towards Aichi Biodiversity Target 2
Northern white rhino population
Number of African elephants
Number of Asian elephants
Number of animal species losing habitat due to cropland expansion by 2050
Number of coral bleaching events
Number of coral bleaching events by stage of the ENSO cycle
Number of parties in multilateral environmental agreements
Number of rhinos poached
Number of seized rhino horns and pieces
Number of severe coral bleaching events by stage of the ENSO cycle
Number of species evaluated for their level of extinction risk
Number of species that have gone extinct since 1500
Number of species threatened with extinction
Number of threatened endemic mammal species
Number of unique plant genetic samples in conservation facilities
Number of whales killed
Projected changes in cropland
Proportion of local livestock breeds at risk of extinction
Protected area coverage of marine key biodiversity areas
Protected area coverage of mountain key biodiversity areas
Seafood production: wild fish catch vs. aquacultureLine chart
Seafood production: wild fish catch vs. aquacultureStacked area chart
Share of Caribbean reefs with Acropora corals present or dominant
Share of described species that have been evaluated for their extinction risk
Share of fish stocks that are overexploited
Share of forest area within protected areas
Share of freshwater Key Biodiversity Areas that are protected
Share of land area that is protected
Share of land covered by forest
Share of marine territorial waters that are protected
Share of ocean area that is protected
Share of populations increasing, stable or declining in the Living Planet Index
Share of species that are traded
Share of species threatened with extinction
Share of terrestrial Key Biodiversity Areas that are protected
Share of traded species that are traded as pets
Share of traded species that are traded as products
Southern white rhino population
Species represented in the Living Planet Index
Status of membership in the International Whaling Commission
Status of the world's fish stocks
Sumatran rhino population
The decline of global whale biomass
The decline of global whale populations
Threatened bird species
Threatened endemic bird species
Threatened endemic reef-forming coral species
Threatened fish species
Threatened mammal species
Total amount donated for biodiversity conservation in developing countries
Total donations received for biodiversity conservation
Transboundary animal breeds with conserved genetic material
Weight of seized rhino horns
What is wild fish catch used for?
Which countries are members of the International Whaling Commission?
Wild fish catch by gear typeStacked area chart
Wild fish catch by gear typeLine chart
Wild fish catch from bottom trawling
Endnotes
WWF (2024) Living Planet Report 2024 – A System in Peril. WWF, Gland, Switzerland.
Leung, B., Hargreaves, A. L., Greenberg, D. A., McGill, B., Dornelas, M., & Freeman, R. (2020). Clustered versus catastrophic global vertebrate declines. Nature, 588(7837), 267-271.
Bar-On, Y. M., Phillips, R., & Milo, R. (2018). The biomass distribution on Earth. Proceedings of the National Academy of Sciences, 115(25), 6506-6511.
Ledger, S.E.H., Rutherford, C.A., Benham, C., Burfield, I.J., Deinet, S., Eaton, M., Freeman, R., Gray C., Herrando, S., Puleston, H., Scott-Gatty, K., Staneva, A. and McRae, L. (2022) Wildlife Comeback in Europe: Opportunities and challenges for species recovery. Final report to Rewilding Europe by the Zoological Society of London, BirdLife International and the European Bird Census Council.
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Our articles and data visualizations rely on work from many different people and organizations. When citing this topic page, please also cite the underlying data sources. This topic page can be cited as:
Hannah Ritchie, Fiona Spooner and Max Roser (2022) - “Biodiversity” Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/biodiversity' [Online Resource]BibTeX citation
@article{owid-biodiversity,
author = {Hannah Ritchie and Fiona Spooner and Max Roser},
title = {Biodiversity},
journal = {Our World in Data},
year = {2022},
note = {https://ourworldindata.org/biodiversity}
}
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