Climate change threatens humanity like few other things in the world. In a new study, researchers have estimated how a growing insect population in a warmer Earth will affect crop yields, and the answer is not good at all.
In Europe alone, scientists estimate that 16 million tons of wheat, maize, and rice per year are likely to be lost to pests by 2050. Eleven European countries will see rates of wheat loss increase by 75 percent or higher. In America and Asia, the situation is equally worrying.
Insect-induced maize losses could increase by almost 40 percent in the US, the world’s largest corn producer. For China, 27 million tons of rice could be lost to insects. As reported in Science, for every 2°C rise in temperature, their model predicts worldwide losses of 31 percent for corn, 19 percent for rice, and 46 percent for wheat. This will correspond to a total crop loss worldwide of approximately 213 million tons for the three grains.
"On average, the impacts from insects add up to about a 2.5 percent reduction in crop yield for every degree Celsius increase in temperature," co-lead author Professor Joshua Tewksbury, from CU Boulder, said in a statement. "For context, this is about half the estimated direct impact of temperature change on crop yields, but in north temperate areas, the impact of increases insect damage will likely be greater than the direct impact of climate on crop yields."
The higher temperature will positively affect pests in temperate regions. Insects have an optimal temperature at which their populations grow best. It needs to be just right – not too hot or too cold. In the tropics, insects are already close to optimal temperature, but that's not the case in temperate regions. This is why those countries will be particularly affected.
"We expect to see increasing crop losses due to insect activity for two basic reasons," co-lead Professor Curtis Deutsch, from the University of Washington, stated. "First, warmer temperatures increase insect metabolic rates exponentially. Second, with the exception of the tropics, warmer temperatures will increase the reproductive rates of insects. You have more insects, and they're eating more."
It may be possible to lessen the impact by breeding insect-resistant crops, or perhaps politicians could stop diddling and tackle the clear and present danger that climate change poses before it’s too late.