What Is Biodiversity?

Biodiversity — short for biological diversity — refers to the variety of life on Earth at all its levels: from genes and individual species, to ecosystems and entire biomes. It encompasses every organism, from the bacteria in a teaspoon of soil to blue whales and ancient rainforest trees.

We often think of biodiversity in terms of headline numbers: how many species of birds exist, or how many plant species are found in a given forest. But it also includes genetic diversity within species (which allows populations to adapt) and ecosystem diversity — the variety of different habitats, from wetlands and coral reefs to grasslands and tundra.

The Scale of the Crisis

Biodiversity is in serious decline. The scientific consensus, summarised by bodies including the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), is that species are being lost at a rate many times higher than the natural background extinction rate — driven overwhelmingly by human activity.

The main drivers of biodiversity loss include:

  • Habitat destruction and fragmentation – Particularly the conversion of forests, wetlands, and grasslands to agriculture or urban areas.
  • Overexploitation – Overfishing, hunting, and unsustainable harvesting of wild species.
  • Pollution – Pesticides, plastic, nutrient runoff, and chemical contamination affecting ecosystems.
  • Invasive species – Non-native species introduced by human activity that outcompete or prey upon native wildlife.
  • Climate change – Altering habitats, disrupting seasonal cycles, and pushing species beyond their thermal tolerances.

Why Biodiversity Matters to Us

It can be tempting to view species loss as a distant, abstract concern. In reality, biodiversity underpins the systems that human societies depend on completely:

Food Systems

Wild pollinators — bees, butterflies, hoverflies, moths — are essential for the reproduction of a large proportion of the world's food crops. Declining pollinator populations directly threaten food security. Soil biodiversity (bacteria, fungi, worms, invertebrates) drives the nutrient cycles that allow farmland to remain productive.

Clean Water and Air

Forests, wetlands, and other ecosystems filter freshwater, regulate rainfall patterns, and help maintain air quality. The loss of these ecosystems degrades the natural services they provide — services that are enormously expensive to replicate artificially.

Medicine

A significant proportion of modern pharmaceutical drugs are derived from or inspired by natural compounds found in plants, fungi, and animals. Many species that haven't yet been studied could hold cures or treatments for diseases — but species lost before they're discovered take their potential with them.

Climate Regulation

Forests, peatlands, and ocean ecosystems are major carbon stores. Their degradation releases stored carbon into the atmosphere, while their protection and restoration are among the most powerful natural tools available for climate mitigation.

What Individuals Can Do

While systemic change — in agriculture, land use policy, and international conservation commitments — is essential, individual actions also matter, particularly in shaping culture and markets:

  • Garden for wildlife – Native plants, reduced mowing, log piles, and water sources support local species significantly.
  • Reduce meat and dairy consumption – Livestock farming is a leading driver of habitat destruction. Shifting diets has measurable impact.
  • Buy sustainably sourced products – Look for credible certification schemes for wood, fish, palm oil, and other commodities linked to habitat loss.
  • Support conservation organisations – Land trusts, rewilding projects, and wildlife charities do critical on-the-ground work.
  • Engage politically – Biodiversity policy is shaped by governments and international agreements. Voting and advocacy matter.

Reasons for Hope

The picture is serious but not hopeless. Species can recover when given the chance. Rewilding projects across Europe, North America, and beyond have demonstrated that ecosystems can regenerate with remarkable speed when pressures are removed and key species are reintroduced. Protected area networks, when properly resourced and enforced, are genuinely effective. And public awareness of biodiversity loss is growing in ways that are beginning to translate into policy change.

Understanding the crisis is the first step to being part of the solution.