The Heat Is Online

Drought Could Imperil US Food Supply


ENS, Nov. 19, 1999

PRINCETON, New Jersey, November 19, 1999 (ENS) - Parts of the central U.S. may experience more frequent drought conditions because of increasing greenhouse gases, according to a computer model run by National Oceanic and Atmospheric Administration (NOAA) scientists.

Researchers at NOAA’s Geophysical Fluid Dynamics Laboratory (GFDL) in Princeton published their findings in the November issue of "Climatic Change." Computer models of Earth's climate, which simulate the interactions among the atmosphere, oceans, land surface and sea ice, are the primary tools in climate change studies. The scientists simulated climate change over the period 1765-2065 by incorporating the effect of increasing greenhouse gases and sulfate particles.

"The central U.S., which includes agricultural states such as Nebraska, Iowa, Kansas, Missouri, and Illinois, along with central Asia, and areas surrounding the Mediterranean Sea will likely experience substantial percentage reductions in soil moisture during the summer season by the middle of the next century. This means that these regions will be particularly vulnerable to more frequent drought conditions and associated reduction in crop yield," said Richard Wetherald, a meteorologist at GFDL and one of the study's authors.

Projected global temperature increases are consistent with real life observations, but Wetherald said that "corresponding increases in drought frequency are unlikely to be statistically confirmed in the near future. Our study suggests that because of the large natural variability inherent in hydrologic processes, such as precipitation, soil moisture, and runoff, confirmation of the projected decrease in soil moisture will be difficult to detect, at least during the first few decades of the twenty-first century."