Farming and climate warming have cut insect populations in half

The effects of climate change and agriculture are severely impacting insects all over the world. A new report from University College London has revealed that the combination of these stressors has reduced insect populations by up to 49 percent.

The study is the first to confirm that rising temperatures and land use changes are responsible for widespread insect losses.

“Many insects appear to be very vulnerable to human pressures, which is concerning as climate change worsens and agricultural areas continue to expand,” said study lead author Dr. Charlie Outhwaite.

“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.

“Our 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.”

For the investigation, the researchers analyzed 750,000 records of insect abundance for nearly 20,000 species. The experts considered how species richness may have been affected by agriculture and climate warming in various regions. 

The analysis showed that in areas with the most intensive agriculture and climate warming, insect abundance was 49 percent lower compared to habitats that were less impacted. 

The researchers noted that insect declines due to human influences may be even greater than their findings suggest, as many areas with long histories of human impacts would have already seen biodiversity losses before the start of the study period.

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

“We have previously found that insect pollinators are particularly vulnerable to agricultural expansion, as they appear to be more than 70% less abundant in high-intensity croplands compared to wild sites.”

According to Dr. Newbold, the careful management of agricultural areas – such as preserving natural habitats near farmland – is needed to help protect insects. 

“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,” said study co-author Peter McCann.

The study is published in the journal Nature.

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By Chrissy Sexton, Earth.com Staff Writer