Insect populations plummet to half — and that’s bad news for humans

Scientists have found that climate change and intensive agricultural land use have almost halved insect populations in some parts of the world.

According to a new study, a warming world and intensive agriculture are responsible for a 49 per cent reduction in the number of insects in the most impacted parts of the world.

The new study published in Nature, a global science and environment journal, is the first to identify that an interaction between rising temperatures and land use changes is driving widespread losses in numerous insect groups across the globe, with researchers explaining that insect populations are being harmed.

According to Dr Charlie Outhwaite,  the lead author, and University College London Centre for Biodiversity and Environment Research, many insects appear to be very vulnerable to human pressures, which is alarming as climate change worsens and agricultural areas continue to expand.

“Our findings highlight the urgency of actions to preserve natural habitats, slow the expansion of high-intensity agriculture, and cut emissions to mitigate climate change.”

“Losing insect populations could be harmful not only to the natural environment, where insects often play key roles in local ecosystems, but it could also harm human health and food security, particularly with losses of pollinators,” the expert highlighted.

20,000 insect species

He further pointed out that their findings may only represent the tip of the iceberg as there is limited evidence in some areas, particularly in the tropics, “which we found have quite high reductions in insect biodiversity in the most impacted areas”.

The researchers analysed a large dataset of insect abundance and species richness from areas across the globe, including three-quarters of a million records for nearly 20,000 insect species and found that in areas with high-intensity agriculture and substantial climate warming, the number of insects was 49 per cent lower than in the most natural habitats with no recorded climate warming, while the number of different species was 29 per cent lower.

Tropical areas saw the biggest declines in insect biodiversity linked to land use and climate change.

Dr Tim Newbold, a senior author of the study, believes that the environmental harms of high-intensity agriculture present a tricky challenge as we try to keep up with food demands of a growing population.

“We have previously found that insect pollinators are particularly vulnerable to agricultural expansion as they appear to be more than 70 per cent less abundant in high-intensity croplands compared to wild sites. Careful management of agricultural areas such as preserving natural habitats near farmland may help to ensure that vital insects can still thrive."

Peter McCann,  joint first author, agrees with him.

"We need to acknowledge how important insects are for the environment as a whole, and for human health and wellbeing in order to address the threats we pose to them before many species are lost forever."

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