Climate change could stymie efforts to feed population

Climate change may hamper the ability of the world’s farmers to increase production enough to feed growing populations, according to new research from Cornell University in New York.

In a paper published in the journal Nature Climate Change, Ariel Ortiz-Bobea, a specialist in applied economics and policy, found that human-driven climate change has reduced agriculture’s potential. While average productivity has more than doubled since 1961, climate change has acted as a drag on this growth.

“Our baseline model indicates that ACC (anthropogenic or human-caused climate change) has reduced global agricultural TFP by about 21percent since 1961, a slowdown that is equivalent to losing the last seven years of productivity growth,” the researchers wrote.

TFP, or total factor productivity, is a measure that looks at total inputs and outputs. TFP statistics include outputs of crops and livestock, as well as inputs such as labour, land, capital and materials. The researchers used this measure since it is more comprehensive than usual yardsticks such as gross domestic product and yields of the major cereal crops. Cereals, for example, account for only 20 percent of global agriculture production.

When they added climate into the mix, the researchers found agricultural TFP was strongly linked, with warmer temperatures over the three-month “green season” detrimental to growth.

Warmer regions are hardest hit, with TFP reductions of 26 to 34 percent in Africa, Latin America, and the Caribbean.

“The large negative impacts for Africa seem particularly worrisome given the large portion of the population employed in agriculture,” the researchers wrote.

The problem also appears to be picking up pace. The researchers split their data into halves: 1962 to 1988 and 1989 to 2015. They found the TFP impacts were “noticeably steeper” for the more recent time period.

“This indicates that higher temperatures have become more damaging,” they wrote, and that global agriculture is becoming increasingly sensitive to climate change.

An often-cited figure from the Food and Agriculture Organization of the United Nations states that the world’s farmers will need to double production to keep everyone fed in the year 2050. A 2017 study led by Mitchell Hunter from Pennsylvania State University and published in the journal Bioscience disputes this. It suggests increasing production by 25 to 70 percent would be enough. But efforts to bring down agricultural greenhouse gas emissions are urgent and essential.