A new study predicts that warming temperatures will lead pests to eat significantly more crops around the world, according to BBC News. Warming both fuels the growth of insect populations, and leads them to burn more energy and consume more food, which means they may eat as much as 10 to 25 percent more wheat, rice, and corn per degree Celsius of temperature increase.
The study was authored by a group of US-based researchers, and was published in the journal Science on Friday.
“Insect pests currently consume the equivalent of one out of every 12 loaves of bread (before they ever get made). By the end of this century, if climate change continues unabated, insects will be eating more than two loaves of every 12 that could have been made,” said University of Washington researcher Curtis Deutsch, speaking to BBC News.
The research focused on 38 species of insects and on the three crops, which combined account for 42 percent of all calories consumed globally. A mathematical model was used to estimate the insect’s energy use, growth response, and the effect on crops.
As a direct result of rising temperatures themselves, crop yields are already expected to decline about 5 percent per degree of temperature increase. According to the authors of the new study, the damage will be increased about 50 percent due to pests.
The impact would be most severe in temperate zones such as Europe, the US, and China, while in tropical areas, higher temperatures could actually reduce insect populations, resulting in reduced crop loss.
Models have already shown that global temperatures may be expected to rise between 2 and 5 degrees by the end of the century. Deutsch notes that “by the time we get to a 2-degree warming by mid-century we would be able to detect the kind of change in insect pest damage that we’re anticipating.”
Plant pathogens carried by insects, altered rainfall patterns, and increased carbon dioxide in the atmosphere could all exacerbate the crop problems even further, according to the researchers.
The researchers suggest adaptations may be necessary to avoid the outcomes, including changes to the planting schedule, rotating crops more often, and planting more resilient crops. With pests better able to adapt to pesticides, we may need new “biological means of controlling pests,” such as ladybirds, according to University of Southampton Ecology Professor Guy Poppy.
Yet, as with all climate change risks, the best path to mitigation is to minimize temperature increases by cutting carbon emissions.