Do climate fluctuations affect global crop yields?

A recent study has estimated the degree to which different modes of climate variability cause volatility in the global and regional production of corn, wheat, and soy.

The study was published in the journal of 'Science Advances'.

"Global agriculture counts on the strong likelihood that poor production in one part of the world will be made up by good production elsewhere," said Weston Anderson, the lead author of the study.

He and his co-authors decided to test this idea by looking at the impact that the El Nino-Southern Oscillation (ENSO), the Indian Ocean Dipole, and other well-understood climate patterns have had on global production of corn, soybeans, and wheat.

They analysed how these modes of climate variability influenced drought and heat in major growing regions.

"We found that ENSO can, and has, forced multiple breadbasket failures, including a significant one in 1983," said Anderson.

The authors found that, on a global level, corn is the most susceptible to such crop failures.

They found that 18 per cent of the year-to-year changes in corn production was the result of climate variability.

Soybeans and wheat were found to be less at risk for simultaneous failures, with climate variability accounting for 7 per cent and 6 per cent of the changes in global production, respectively.

"The bigger the uncertainty around climate drivers, the bigger the risk for those involved in the food systems," said co-author Liangzhi You, a senior research fellow at the International Food Policy Research Institute.

"The worst affected are poor farmers in developing countries whose livelihoods depend upon crop yields as they do not have an appetite for risks in the absence of formal insurance products or other coping mechanisms."

"ENSO may not be important in all years, but it is the only thing we know of that has forced simultaneous global-scale crop failures," said Anderson.