Scientists have identified systematic meanders in the globe-circling northern jet stream that have caused simultaneous crop-damaging heat waves in widely separated breadbasket regions–a previously unquantified threat to global food production that, they say, could worsen with global warming.
Scientists have identified systematic meanders in the globe-circling northern jet stream that have caused simultaneous crop-damaging heat waves in widely separated breadbasket regions–a previously unquantified threat to global food production that, they say, could worsen with global warming. The research shows that certain kinds of waves in the atmospheric circulation can become amplified and then lock in place for extended periods, triggering the concurrent heat waves. Affected parts of North America, Europe and Asia together produce a quarter of the world food supply. The study appears this week in the journal Nature Climate Change.
“We found a 20-fold increase in the risk of simultaneous heat waves in major crop-producing regions when these global-scale wind patterns are in place,” said lead author Kai Kornhuber, a postdoctoral researcher at Columbia University’s Earth Institute. “Until now, this was an underexplored vulnerability in the food system. During these events there actually is a global structure in the otherwise quite chaotic circulation. The bell can ring in multiple regions at once.”
Kornhuber warned that the heat waves will almost certainly become worse in coming decades, as the world continues to warm. The meanders that cause them could also potentially become more pronounced, though this is less certain. Because food commodities are increasingly traded on a global scale, either effect could lead to food shortages even in regions far from those directly affected by heat waves.
Read more at Earth Institute at Columbia University
Image: Farmland in eastern Oklahoma, one of the farflung regions that researchers have found are susceptible to simultaneous heat waves. (Credit: Kevin Krajick/Earth Institute)
