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Reversing biodiversity loss

Find answers to 16 key questions about biodiversity

  • Introduction

    At its simplest, biodiversity describes life on Earth – the different genes, species and ecosystems that comprise the biosphere and the varying habitats, landscapes and regions in which they exist. We've answered some of your most popular questions about biodiversity.

    Find out more

  • What is biodiversity?

    Biodiversity is all the living things on our planet – from the smallest bacteria to the largest plants and animals. So far, we have identified around 1.6 million species but that is probably only a small fraction of the forms of life on Earth.

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  • Why is biodiversity important?

    Biodiversity is essential for the processes that support all life on Earth, including humans. Without a wide range of animals, plants and microorganisms, we cannot have healthy ecosystems.

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  • How do we measure biodiversity?

    There is still much we do not know about the complexity of biodiversity on Earth. There are a number of ways that we measure it, with counting species the most common approach.

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  • What is the scale of biodiversity loss?

    The list of known recent extinctions is still a small fraction of all species on the planet but it is far above prehuman levels and the evidence suggests it is rising fast.

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  • We regularly hear of new species being discovered - does that not offset the loss of existing species?

    Every year thousands of previously unknown species are discovered, described and named.

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  • Where is most biodiversity loss happening and why?

    Biodiversity loss has been most pronounced on islands and in specific locations around the tropics.

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  • Is the rate of biodiversity loss increasing or decreasing?

    Compared to the 1.6 million species known about on Earth, the number of recorded extinctions can seem very low.

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  • What is the state of biodiversity in the UK?

    The UK boasts more than 70,000 known species of animals, plants, fungi and microorganisms.

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  • How do humans affect biodiversity?

    Humanity impacts the planet's biodiversity in multiple ways, both deliberate and accidental.

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  • How does the growing global population and increasing consumption affect biodiversity?

    Since the middle of the 20th century, the human population has grown dramatically.

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  • How does climate change affect biodiversity?

    The environmental changes being driven by climate change are disturbing natural habitats and species in ways that are still only becoming clear.

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  • How does deforestation affect biodiversity?

    Forests contain some of the richest concentrations of biodiversity on the planet. But between 1990 and 2020, around 420 million hectares of mainly tropical forest has been lost.

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  • What can we do to protect biodiversity?

    Loss of natural habitats has been taking place over thousands of years, but scientists are confident that we have ways to help biodiversity recover.

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  • What can I do as an individual to protect biodiversity?

    While large scale changes in behaviour, policies and measures will be essential, individuals have a vital part to play.

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  • Can we allow nature to regenerate without intervention?

    Biodiversity loss is a complex issue involving many overlapping processes. While nature can recover when left to do so, it requires dramatic changes in our behaviour for this to happen.

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  • How do we decide what is worth saving or putting our efforts into protecting?

    The value of the natural world can be interpreted in many ways, from their raw economic value to the inherent social, cultural and emotional benefits they provide.

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Watch Sir David Attenborough on why we need nature

At its simplest, biodiversity describes life on Earth – the different genes, species and ecosystems that comprise the biosphere and the varying habitats, landscapes and regions in which they exist. The Earth is losing biodiversity at rates not seen in human history. Following the success of the Royal Society’s Climate Change: Evidence and Causes and GM Plants: questions and answers, the Society decided to produce a similar document on biodiverstiy, identifying questions from the public and then answering them as accurately and as dispassionately as possible.

To identify the questions, we looked at the most popular questions asked online and questions asked by members of the public at the Society’s You and the Planet event on biodiversity.

The answers to the questions were written by a group of experts who have endeavoured to ensure the answers are factual, as much as possible, and not associated with any value judgement. The aim was not to present comprehensive reviews with scientific details, but instead to provide succinct accounts that will be accessible to non-scientists.

The Royal Society has also published a statement, Biodiversity – evidence for action (PDF), that sets out an overarching strategy and vision for biodiversity and has also commissioned a series of essays from global experts in fields as diverse as conservation, ecology, environmental change, economics and population. They are intended to stimulate discussion on the problems and potential solutions to halt and reverse the decline in biodiversity.

The questions and answers given here are intended to provide a resource to those who are interested in what biodiversity is, the threats it is facing to give some insight into what we can do to tackle biodiversity loss.


The main authors were:

  • Yadvinder Malhi CBE FRS, Professor of Ecosystem Science at the University of Oxford and Chair of the Royal Society Steering Group on Biodiversity
  • Andrew Balmford FRS, Professor of Conservation Science, University of Cambridge and member of the Royal Society Steering Group on Biodiversity
  • Sir Ian Boyd FRS, Professor, School of Biology, University of St Andrews and member of the Royal Society Steering Group on Biodiversity
  • Sandra Díaz ForMemRS, Professor of Community and Ecosystems Ecology, National University of Córdoba and CONICET, Argentina and member of the Royal Society Steering Group on Biodiversity

We would also like to thank the following for their contribution in reviewing the answers:

  • Alex Burch, Director of Public Programmes, Natural History Museum and member of Royal Society Public Engagement Committee
  • Diane Coyle, Bennett Professor of Public Policy, University of Cambridge 
  • Carlos Frenk CBE FRS, Ogden Professor of Fundamental Physics, Durham University and Chair of the Royal Society Public Engagement Committee
  • Dilys Roe, Principal researcher and team leader (biodiversity), Natural Resources Group, International Institute for Environment and Development
  • Hannah Taylor Lewis, Science Media Centre

Further reading

Scientific essays about biodiversity

  • The economics of biodiversity: The Dasgupta review

    By Partha Dasgupta

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  • Plural valuation of nature matters for environmental sustainability and justice

    By Berta Martín-López

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  • Why efforts to address climate change through nature-based solutions must support both biodiversity and people

    By Nathalie Seddon

    Read the essay

  • Past and future decline and extinction of species

    By Christopher N. Johnson

    Read the essay

  • Amazonia’s future: Eden or degraded landscapes?

    By Thomas E Lovejoy

    Read the essay

  • Behaviours for conserving biodiversity

    By R M Cowling

    Read the essay

  • Consumption patterns and biodiversity

    By Jianguo Liu

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  • Demographic trends and policy options

    By John Bongaarts

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  • Emergent and vanishing biodiversity, and evolutionary suicide

    By Simon A Levin

    Read the essay

  • Preserving global biodiversity requires rapid agricultural improvements

    By David Tilman and David R. Williams

    Read the essay

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