Climate Change Increases Risk of Crop Growth Slowdown in Next 20 Years

Climate change may impact ecosystems, but it also may impact the world's supply of food. Scientists found that the planet faces a small but substantially increased risk over the next two decades of a major slowdown in the growth of global crop yields due to changing weather patterns.

"Climate change has substantially increased the prospect that crop production will fail to keep up with rising demand in the next 20 years," said Claudia Tebaldi, co-author of the new study, in a news release.

In order to better understand how climate change might influence world food supplies, the researchers used computer models of global climate, as well as data about weather and crops. They then calculated the chances that climatic trends would have a negative effect of 10 percent on yields of corn and wheat in the next 20 years. This would have a major impact on food supply.

The researchers quantified the extent to which warming temperatures would correlate with reduced yields. For example, an increase of 1.8 degrees Fahrenheit would slow corn yields by 7 percent and what yields by 6 percent.

So what did they find? The scientists discovered that the likelihood that natural climate would cause such a slowdown over the next 20 years is only 1 in 200. Yet when the researchers accounted for human-induced global warming, they found that the odds jumped to 1 in 10 for corn and 1 in 20 for wheat.

"I'm often asked whether climate change will threaten food supply, as if it's a simply yes or no answer," said David Lobell, one of the researchers, in a news release. "The truth is that over a 10- or 20-year period, it depends largely on how fast Earth warms, and we can't predict the pace of warming very precisely. So the best we can do is try to determine the odds."

The findings reveal that yields could certainly slow in the coming years and that the odds that they will slow are much higher than expected.

"We can't predict whether a major slowdown in crop growth will actually happen, and the odds are still fairly low, but climate change has increased the odds to the point that organizations concerned with food security or global stability need to be aware of this risk," said Tebaldi in a news release.

The findings are published in the journal Environmental Research Letters.