Alarm Bells Ring for Wheat

Climate change hits wheat production; each degree of temperature rise shrinks wheat trade by a quarter

We better check our appetite for these steaming rolls of bread, and check it fast! For, a study by researchers from the Kansas State University shows that unless urgent measures are taken, there will be radical drops in the production and trade of wheat because of rises in global air temperatures triggered by climate change and sudden extremes of heat or cold.

In the study published online in Nature Climate Change, researchers have calculated that a rise of just 1°C in global temperatures will result in a six-percent drop in production. Noting that world total for wheat production was 701 million tons in 2012, researchers say the six-percent drop translates into a production shortfall of 42 million tons. Suppose the national wheat harvest failed to meet the targeted figure. You can no longer say “Don’t panic folks; we can always import the amount we need with hard cash,” since these shortfalls in yield also curtail the wheat trade. The global trade volume for wheat has been 147 million tons in 2013. This means that a 42-million-ton shortfall for every 1°C rise in global temperatures will shrink world wheat trade by 25 percent.

Researchers arrived at these results after conducting field experiments with 30 different wheat models. The experiments were done under temperatures ranging from 15°C to 32°C. An important finding from the experiments is that high temperatures during the development of the wheat shortens the period for the plant to produce and fill the seeds through photosynthesis. The result is a flimsy head with a reduced number of seeds. Also measuring the effect of sudden heat waves during growth time in laboratory experiments, the team found that yield dropped to zero under 34°C.

According to researchers, the effect of temperatures on yields becomes more marked in low latitudes closer to the equator. The maps of yield projections in the study predict a 8-percent drop in production in the area where Turkey is located with a 2°C temperature increase, the loss growing to 12 percent with a 4°C rise.

Professor Vara Prasad, a co-author of the study, underlines the fact that the effect of climate change on wheat production had gone beyond what was predicted until now. “It’s pretty severe,” Prasad says. “The projected effect of climate change on wheat is more than what has been forecast. That’s challenging because the world will have to at least double our food supply in the next 30 years if we’re going to feed 9.6 billion people.” The researcher hopes the losses could be reduced through genetic studies and more advanced crop management techniques.