New research from the University of Colorado Boulder suggests rising global temperatures will have a greater impacts on crop yields than previously predicted. The reason: Bug populations are going to be bigger and hungrier.
The study, published in the journal Science, found temperate climates like those in North America and Europe will see the greatest impact. Europe’s breadbasket, the most productive region for wheat in the world, could be the hardest hit.
Here’s how the bug explosion could happen: As summers get longer, bug populations will have more time to breed. The rise in temperature will allow them to move into new ecosystems and make their gestation time faster. Worst of all, it will boost their metabolisms — and their appetites.
CU Boulder research professor and co-author Josh Tewksbury said until now, most studies examined how rising temperatures bring down crop yields. Those studies have found that for every one degree in temperature rise, crop yields drop by about five percent.
But these earlier models didn’t consider how losses would be impacted by insects.
“What we show is that in many temperate areas, we might be getting close to doubling that, because we’re adding in the impact of insects,” he said.
If the global temperature rises by two degrees, crops like corn, which are vital to U.S. agriculture, could see loses from insects rise by 40 percent. For wheat, it’s estimated to jump to 50 or even 100 percent. But Tewksbury said hungry bugs don’t discriminate.
“Our results are not specific to wheat and maize. They’re about agricultural pest increases full stop,” he said.
Tewksbury, who focuses on sustainability science, says the reality of a two-degree rise in global rise temperature isn’t far off – even if the world adheres to recommendations like the Paris Climate Agreement.
“If we continue as we are now, that’ll happen in the next 30 years,” he said.
The forecast is rather ominous, but the study lists a number of potential solutions, like using more pest and heat resistant crops. Tewksbury hopes future farmers will find more creative solutions than simply applying more pesticides. He notes that as pest populations increase, so too will the populations of wasps and other bugs who eat them.
“Those are our allies in this fight because those organisms can be employed to stop the growth of the insects that wipe out our crops,” he said.