Climate boundary shifts 140 miles to east

A boundary that divides the humid eastern U.S. and the dry western Plains appears to have shifted 140 miles to the east over the past century due to global warming, new research suggests.

Scientists say it will almost certainly continue shifting in coming decades, expanding the arid climate of the western Plains into what we think of as the Midwest. The implications for farming could be huge.

The boundary line was first identified in 1878 by the American geologist and explorer John Wesley Powell. At that time, it was at 100 degrees west longitude, also known as the 100th meridian.

“Powell talked eloquently about the 100th meridian, and this concept of a boundary line has stayed with us down to the current day,” said Richard Seager, a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory and lead author of two new studies about the shifting climate boundary.

Running south to north, the 100th meridian cuts through Texas, Oklahoma, Kansas, Nebraska and the Dakotas. It’s considered the beginning of the Great Plains.

Both population and development are sparse west of the 100th meridian, where farms are larger and primarily depend on crops like wheat that do well in arid climates, the Yale School of Forestry & Environmental Studies said. To the more humid east, more people and infrastructure exist. A large portion of the harvest is moisture-loving corn.

The studies appeared in the journal Earth Interactions, a publication of the American Meteorological Society.