Extreme and volatile weather patterns are especially threatening to durum, which is more finicky than conventional wheat varieties. If too much rain falls at the wrong time, durum’s quality can be ruined. Too little rain isn’t good either. Because durum is trickier to grow, farmers require a price premium over what conventional wheat earns. Already, Opland and other farmers complain, grain companies have been shrinking these premiums to boost their own profit margins. As climate change intensifies and durum gets even harder to grow, how high will the price premium have to rise to entice farmers to take the risk? Opland wonders whether he will plant durum at all next year.

Nonspecialists sometimes suggest that agriculture can easily adapt to climate change by shifting crops to more climatically congenial locations. Last July, Rex Tillerson, the CEO of ExxonMobil, called climate change “an engineering problem [that] has engineering solutions,” one of which is to “move crop production areas around.”

But reality is not so simple. “If you eat most of what you grow, as is the case for many farmers in the world’s poorest countries, moving your farm is not an option,” IFPRI’s Nelson points out. Indeed, even a more prosperous farmer in North Dakota can’t just pick up and move to follow changing weather conditions.