APRIL 11, 2018
The divide cuts through eastern Mexico, Texas, Oklahoma, Kansas, Nebraska, the Dakotas, and the Canadian province of Manitoba. West of the 100thmeridian, population density declines and development is sparse, and farms are larger and primarily depend on arid-resistant crops like wheat. To the more humid east, more people and infrastructure exist. Farms are smaller and 70 percent of the harvested crop is moisture-loving corn.
Studying rainfall and temperature data since 1980, Seager and his colleagues found this climatic boundary has already shifted east about 140 miles so that it now sits closer to the 98th meridian. And it will continue to move east as warming global temperatures increase evaporation from the soil and change precipitation patterns, they concluded.