Climate change is on track to reduce by 11 percent in 2100 the yields that today provide two-thirds of humanity’s calories from crops, even taking into account adaptation to a warming world, scientists said Wednesday.
As soon as 2050, this “moderate” scenario in which greenhouse gas emissions peak around 2040 and slowly taper off — a trajectory aligned with current trends — would see global losses of nearly eight percent.
And if carbon pollution worsens, the loss of calories across the same six staples — corn, wheat, rice, soybeans, sorghum and cassava — rises to nearly a quarter by century’s end, the researchers reported in Nature.
More generally, every additional degree Celsius of warming reduces the world’s ability to produce food from these crops by 120 calories per person per day, or nearly five percent of current daily consumption, they calculated.
“If the climate warms by three degrees, that’s basically like everyone on the planet giving up breakfast,” said co-author Solomon Hsiang, a professor at the Stanford Doerr School of Sustainability in California.
The steepest losses will occur at the extremes of the agricultural economy: in modern, Big Ag breadbaskets that currently enjoy some of the world’s best growing conditions, and in subsistence farming communities that typically rely of small cassava harvests.
North America would be hit hardest, losing a fifth of yields by 2100 in the moderate carbon pollution scenario, and two-fifths if emissions from burning fossil fuels continue apace.
Working with more than a dozen scientists, Hsiang and co-leader Andrew Hultgren, an assistant professor at the University of Urbana-Champaign, sifted through data from more than 12,000 regions in 55 countries.