Agriculture, Climate Change, Insect Predation

"Insects have consumed something like one out of every eight loaves of bread before it even gets made [by consuming large amounts of agricultural crops]."
"If we warmed four degrees which is what climate models typically predict for the end of this century, then that amounts to insects eating two of our eight loaves of bread instead of one."
"If we think about food supply as the pie we all get to eat, some us of get smaller slices than others. If the pie begins to shrink, we need to find ways to stop it from shrinking and to carve it up more evenly so people aren’t left without."
"If you want to solve a big problem with a million tendrils, you have to go to the root of it, otherwise, you're manufacturing a million Band-Aids."
Curtis Deutsch, professor of chemical oceanography, University of Washington, Seattle

"[Beneficial insects thriving alongside the destructive ones could end up] offering some suppression of the pests, so that the damage may not be as great as they [researchers] are suggesting."
Michael Hoffman, professor of entomology, Cornell Institute for Climate Smart Solutions

Grasshoppers are among the insects predicted to grow hungrier and more populous in a warming climate, devastating U.S. corn crops.  James P. Blair/National Geographic/Getty Images

At  the present time insect predation on food crops worldwide means that pest insects competing with humans for the agricultural produce we depend upon to feed the world's population misses out on one loaf of bread from every eight loaves produced. Those insects consume up to twenty percent of the crop plants that we grow for our tables. With global warming that percentage of 'wasted' grain eaten by insect populations is expected to increase substantially, according to a study published recently in the journal Science.

This leads to a situation where farmers, in defence of their crops, will take to using more pesticides, a vicious cycle leading to further environmental degradation.  The amount of wheat, corn and rice consumed by insects is set to increase by ten to 25 percent for every heightened temperature degree above the global historical average, the study emphasizes. Its effect on  temperate agricultural regions such as the United States and Western Europe will see agriculture production especially hard hit.

Insects become hungrier the higher the temperature which causes their metabolism to react and this affects their life cycle which becomes faster, in turn causing them to reproduce more frequently, a set of circumstances that is certain to diminish crop yields at the very time that human population growth is on the upswing, requiring more food to be made available to maintain hungry people. Yet the global food supply will be stressed beyond its capacity to provide that food for a growing global population.

Dr. Deutsch and  his research colleagues made use of statistical models simulating the effects of global warming on insect feeding and reproductive patterns to arrive at their calculated conclusion. Corn and rice crops were the major focus since they represent 42 percent of calories consumed by humans. On the other hand, as Dr. Hoffman points out, beneficial insects could conceivably balance out the equation on a more optimistic note for the future.

But there are other, related issues involved, as pointed out in a study published in the journal Nature Communications, last year which found that projected pressures from increased summer temperatures could lead, in any event, to a reduction in agricultural yields, resulting from higher temperatures and fewer rain events. These researchers are in general agreement that prevention practised to reduce the level of greenhouses gases may hold the only hope for a solution.

New research suggests the risk climate change poses to agriculture is higher than scientists realized because of the way insects respond to warmer temperatures. Credit: Paul J. Richards/Getty Images