RACHEL MARTIN, HOST:
More than a century ago, American explorer John Wesley Powell described a divide through the middle of the country. To the west, it was arid. To the east, more humid. Powell predicted this would profoundly influence where and how people live and farm. Joe Wertz of StateImpact Oklahoma brings us this story. It's the latest in our series on the impacts of a warming climate.
JOE WERTZ, BYLINE: Rancher Benji White pulls into a field at his family's ranch in western Oklahoma, which is framed by low hills and a shady, tree-lined gully.
(SOUNDBITE OF HORN HONKING)
WERTZ: And before the shifter hits park and the doors close behind him and his wife, Lori, the silver Ford pickup is surrounded.
(SOUNDBITE OF CATTLE LOWING)
LORI WHITE: The Red Angus breed - the main thing they're known for kind of is the docility of them is great, the temperament.
WERTZ: Red Angus pack on weight quickly and make well-marbled meat. The family breeds and sells the cattle to customers across the country. The Whites used to grow wheat and other grains but ran into trouble with drought and an erratic market. So they left crops to focus on raising cattle.
BENJI WHITE: Farming is kind of a one-shot deal. And if you don't get rain, where we're completely dry land, then you lose everything. Crop insurance doesn't really pay for all the expenses.
WERTZ: The change was one family's decision. But scientists say this shift, turning cropland into range land, could happen a lot more often. The arid American West appears to be moving east.
RICHARD SEAGER: It's just a steady progression over the last 30-something years.
WERTZ: Richard Seager is a climate scientist and professor at Columbia University. And he's the lead author of new research on the climate boundary that divides the country. For a century, that boundary, which separates arid western states with more humid ones in the east, has been located near the 100th meridian, which runs north from Mexico right through western Oklahoma. Seager says climate change is pushing that boundary to the east.
SEAGER: That's partly because of rising temperature, which increases the amount of moisture the atmosphere can take out of the surface. But it's also part because of projections of declining winter precipitation in the Southwest.
WERTZ: Seager says this climate boundary has likely moved 140 miles so far, closer to the 98th meridian. Jerry Hatfield runs the National Laboratory for Agriculture and the Environment in Ames, Iowa. He says, if climate trends continue...
JERRY HATFIELD: There will be areas of the United States that were typically called the Corn Belt that may not be reliable as the Corn Belt.
WERTZ: Hatfield says the weather is already less reliable in the Midwest, which has long enjoyed steady precipitation and temperatures. Now, he does not think the Corn Belt is going to turn into a dustbowl anytime soon. But Hatfield says even small changes can hurt crop yields.
HATFIELD: I mean, all we need is, you know, maybe 2 or 3 inches less than the annual rainfall.
WERTZ: He says farmers could still see great yields in some seasons, and they're always tweaking crop varieties and soil management practices to adjust to changing conditions. But some farmers might not be able to afford to adapt.
Benji White can't imagine trying to grow crops with less rain and moisture in his fields. He knows a lot of farmers who left the business after the drought that devastated Oklahoma in 2011.
B. WHITE: Cost of equipment, fertilizer, lack of rain - it's just hard to make it pencil out when you're trying to do it to make a profit.
(SOUNDBITE OF TONE CHIMING)
WERTZ: The White family is betting that Red Angus can carry their business through the climate shift. The animals are hardy and sweet, and their red hide means they'll stay cool and grow big when the next drought comes.
For NPR News, I'm Joe Wertz in Oklahoma City.
(SOUNDBITE OF TRAMPIQUE'S "EARTH") Transcript provided by NPR, Copyright NPR.