Explained: What does biodiversity mean?
Drawing on the most highly searched questions on the internet, we explain in simple terms the ins and outs of our planet’s loss of wildlife.
Thousands of people ask every day: What is biodiversity? Why is biodiversity loss bad?
Biodiversity loss is one of the biggest threats facing human and planetary health, yet it remains a largely undiscussed and unknown issue. Questions pile up in their thousands about what exactly biodiversity means and why biodiversity loss is such a big problem.
‘Biodiversity’ means the variety and abundance of the world’s plants and animals. We refer to biodiversity on a global scale – for example when we talk about the one million species at risk of extinction – and at local level: a rainforest harbours tens of thousands of different species, making it rich in biodiversity, whereas a palm oil plantation often has only one type of tree and supports very few other species, meaning that it lacks biodiversity.
Biodiversity loss refers to the decline in the number and abundance of plant and animal species worldwide. It reflects the increasing worldwide extinction of species. Biodiversity is declining faster than at any time in recorded history: the current rate of global biodiversity loss is estimated to be 100 to 1,000 times higher than typical natural extinction rates seen in planetary history.
Every species plays a role that is important for the survival of other species. Collectively, these mutually dependent life forms make up an ecosystem. An ecosystem: an ecosystem is a community of living things that all interact with one another. This is the web of life. Removing any part of this web will have a knock-on effect on the rest of it.
Here’s a popular example: when wolves were hunted out of Yellowstone National Park, the numbers of their main prey – elk – vastly increased. The growing population of elk ate more of the young willow and aspen trees. Shortly after, songbirds started to decline and the beavers – who relied on willow trees to survive in the winter – built fewer dams, in turn affecting freshwater fish. And the chain reaction went on.
As species go extinct, the complex and fragile connections within ecosystems are broken, causing a domino effect that threatens the survival of other species.
When wolves were hunted out of Yellowstone National Park in the 1920’s, it caused profound changes to the ecosystem. Credit: Adobe
Everything we rely on – food, water, shelter, clothing, the air that we breathe – is dependent on the health of nature. The fruits and vegetables we eat rely on bats and insects for pollination. Cotton plants need healthy soil and fresh water to grow. Even the water we drink is the product of a natural cycle.
If biodiversity continues to decline, it will also lead to the breakdown of ecosystems, from forests to the ocean, that are crucial for storing carbon from the atmosphere, worsening the impacts of climate change.
The World Bank estimates that the global economy could lose as much as $2.7 trillion every year by 2030 if the rate of biodiversity loss and ecosystem collapse continue. This is because of the impact it will have on economic activities including fisheries, farming and forestry.
The primary causes of biodiversity loss stem from human activity. Climate change, pollution and habitat destruction are some of the main reasons that species are going extinct. Here are some examples of the most problematic human activities causing biodiversity loss:
Agriculture: Forests are cleared and wetlands are drained to make way for crops, plantations and livestock. Harmful pesticides used on crops are driving down insect populations, and the run-off is polluting rivers, threatening freshwater species.
Overfishing: Overfishing means fish are being harvested from the ocean at a rate too high for stocks to replenish themselves. This is driving fish populations to dangerously low levels.
Deforestation: Cutting down trees is driven by land clearance for farming, roads, housing developments and the timber industry. In 2021, the world’s lost forest area was greater than the size of the UK. Globally, forests are home to more than 80% of the world’s land-based plants and animal species.
Forests hold over 80% of the world’s land-based species, yet they are being cleared at alarming rates worldwide. Credit: © Ruben Banuelo Bons/FFI
According to the latest WWF Living Planet Report, Latin America and the Caribbean has suffered the largest declines in biodiversity anywhere in the world, with a 94% decrease between 1970 and 2018. The main cause of this dramatic decline is likely to be the destruction of the Amazon rainforest, which is seeing record-high rates of deforestation. Declines in this region are most severe in freshwater fish, amphibians and reptiles.
Reptiles, freshwater fish and amphibians are seeing the sharpest species declines. Credit: Jeremy Holden/FFI
If we want others to take action, we have to start the conversation. Engage your friends, co-workers and stubborn in-laws by following these easy-to-understand talking points.