Intensified rainstorms predicted for many parts of the United States as a result of warming climate may have a modest silver lining: they could more efficiently water some major crops, and this would at least partially offset the far larger projected yield declines caused by the rising heat itself. The conclusion, which goes against some accepted wisdom, is contained in a new study published this week in the journal Nature Climate Change.
Numerous studies have projected that rising growing-season temperatures will drastically decrease yields of some major U.S.crops, absent adaptive measures. The damage will come from both steadily heightened evaporation of soil moisture due to higher background temperatures, and sudden desiccation of crops during heat waves. Some studies say that corn, which currently yields about 13 billion bushels a year and plays a major role in the U.S. economy, could nosedive 10 to 30 percent by the mid- to late century. Soy–the United States is the world’s leading producer–could decline as much as 15 percent.
Since warmer air can hold more moisture, it is also projected that rainfall will in the future come more often in big bursts, rather than gentle downpours–a phenomenon that is already being observed in many areas. Many scientists have assumed that more extreme rains might further batter crops, but the new study found that this will probably not be the case. The reason: most of the projected heavier downpours will fall within a range that benefits crops, rather than passing the threshold at which they hurt them.
Read more at Columbia University
Photo: Farmland in eastern Oklahoma, part of the study area. CREDIT: Kevin Krajick/Columbia University