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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. Despite being 'new' to science, these plants and animals were already part of our planet's biodiversity and so cannot compensate for the loss of species we already know about. 

It has been estimated that unidentified species could account for around 80% of species. We are currently thought to only know about 1.6 million species, with around 18,000 previously unidentified ones being added to our catalogue of life annually.

There is evidence, however, that some species are becoming extinct before they are even discovered, which could mean estimates of global extinction rates are likely to be too low. Species are already being lost at an unprecedented rate due to human activities that are causing land and coastal use change, pollution, over-exploitation, introduction of foreign species and climate change. In 2019, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services warned that about 1 million species of plants and animals are now threatened with extinction. 

The loss of a species from a habitat also has wider implications. Species rely upon each other in interconnected webs known as ecosystems. When one species dies out, it can have a knock-on effect on the others within the same ecosystem. This can be as simple as meaning a loss of an important food source or result in the loss of more complex interactions that are important for a habitat. The loss of a keystone species like a large herbivore from forest or woodland, for example, can change the dynamics of a forest. Diminishing numbers of insects can leave habitats with fewer important pollinators and reduce the recycling of nutrients. 

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.

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  • 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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