The dramatic decline in global biodiversity is attributed principally to habitat loss, invasive alien species, over-exploitation of natural resources and pollution. Humanity is to blame for each of these causes of biodiversity loss.

The main culprit is land degradation, the destruction of natural habitat to accommodate urbanisation, industrial development, aquaculture and the expansion of agriculture, including feed for biofuels. The UN’s Global Biodiversity Outlook 2014 estimates that “drivers linked to agriculture account for 70 per cent of the projected loss of terrestrial biodiversity.” More than one third of the planet’s land surface is utilised for crops and grazing of livestock.

The introduction of alien species has caused untold damage to native plants and animals. Some of this invasive interaction dates back centuries and has been accidental, for example through the inadvertent transport of rats, cats, and even jellyfish.

Inability to control the global fishing industry provides the most obvious example of unsustainable use of natural resources. According to the UN Food and Agriculture Organization, 28.8% of marine fisheries were over-exploited in 2011. The FAO has further warned that, without radical measures, commercial fishing may not survive beyond 2050.

Many of the world’s rivers have been rendered inert by dumping or careless use of industrial and agricultural chemicals. Nitrogen run-off from fertilizers encourages algae blooms which starve aquatic life of oxygen through eutrophication. On land, there is currently great alarm at the apparent link between the neonicotinoid range of insecticides and the plunging population of bumblebees.

In varying degree, each of these direct causes of biodiversity loss is a servant to humanity’s insatiable demand for food, water, energy and consumer goods. In turn these demands are inflated by indirect factors such as world population growth and increasing per capita incomes.

For example, the UN’s World Population Prospects estimates that cities in developing countries must expand in anticipation of doubling their populations by 2050. Most of these cities are located in biodiversity-rich tropical regions.

Dr Thomas Elmqvist, scientific editor of Cities and Biodiversity Outlook discusses the threat to biodiversity from rapid urbanisation forecast for coming decades
from Stockholm Resilience Centre

A further indirect cause of biodiversity loss is the dysfunctional performance of contemporary market economics. Inappropriate price signals are the inevitable consequence of attributing zero value to environmental assets.

This failing is compounded by political mismanagement of key global economic instruments. For example, even the highly developed economies of Europe and US have proved incapable of removing subsidies which are complicit in unsustainable farming practices. Global monopolies in agribusiness are permitted to flourish, narrowing the diversity of crops that feed the world.

The rules of international trade and investment also contribute to biodiversity loss by lowering the barriers to acquisition of natural resources. As these are mostly located in countries lacking in economic muscle, their rich biodiversity is exposed to exploitation. An Australian research paper published in Nature in June 2012 concludes: “developing countries find themselves degrading habitat and threatening biodiversity for the sake of producing exports.”

A feature by The Economist considers how the causes of biodiversity loss relate to economic development


more Biodiversity briefings (updated May 2018)
The Anthropocene
Importance of Biodiversity
Biodiversity Loss and Planetary Boundaries
Climate Change and Biodiversity
Conservation of Biodiversity
Solutions to Biodiversity Loss
Sustainable Development Goals for Biodiversity
Biodiversity Finance and Economics
Biodiversity Access and Benefit-Sharing
Source Material and Useful Links