Since the middle of the 20th Century, the human population has grown dramatically from around 2.6 billion to reach 7.8 billion in 2021. Housing and feeding so many people has accelerated the destruction of natural habitats, while higher levels of consumption, particularly in some richer parts of the world, have also increased the exploitation of natural resources and led to growing levels of pollution.
Perhaps the greatest threat to biodiversity from a growing population is from the rapidly increasing per capita consumption. There has been an unprecedented increase in consumption, with about 10% of the world's population in the G7 countries consuming 40% of the Earth's biological productivity. Increasing levels of meat consumption, for example, have required more land for livestock while burgeoning water use has increased the risk of drought in some regions. Similar patterns can be seen in the demand for other natural resources.
As human populations have grown, habitat destruction such as deforestation also increases to make way for agricultural land. Between 1962 and 2017, it is estimated that 340 million hectares of new croplands were created globally and 470 million hectares – around half the area of China - of natural ecosystem were converted into pastures.
Urban sprawl, along with the associated transport infrastructure, can radically transform habitats, increase pollution, raise ambient temperatures and increase the risk of non-native species being introduced by human movements.
While the International Union for Conservation of Nature predicts that the numbers of threatened species is likely to increase rapidly in regions where human population growth rates are high, the demands of consumers also impact biodiversity in areas far away. International trade is reported to be responsible for 30% of global species threats and one study found that 17% of total biodiversity loss occurs due to the commodities that are produced for export to other parts of the world – largely the rich, industrialised nations.
With global population expected to reach 10.9 billion by the end of the century, the impact that humans have on biodiversity is expected to accelerate unless steps are taken to reduce consumption and modify our current global food system. In particular the people of the poorer lower and middle income countries will also wish to increase their consumption over the coming decades in order to raise their standards of living. The richer industrialised countries will need to take steps to reduce their high levels of consumption to compensate for this.
To find out more; Consumption patterns and biodiversity | Royal Society; Demographic trends and policy options | Royal Society