Global warming may cause greater wheat yields, steeper price spikes: study

BEIJING, Aug. 23 (Xinhua) -- What will a hotter Earth bring to wheat consumers and farmers? A new study predicts that global prices for the grain will exhibit steeper spikes at 2 degrees Celsius warming despite a slight increase in production.

Wheat is the world's major grain crop, providing 20 percent of the protein and calories for more than 3.5 billion people worldwide.

The Paris climate agreement aims to keep the global average rise in temperature below 2 degrees Celsius. Scientists believe that even if the target is fulfilled, global warming will alter wheat yields and prices in the coming years.

Unlike previous research on climate impacts on yields alone, the new study, published in the journal One Earth, has demonstrated a new climate-wheat-economic model system. It allows scientists to look at the impacts of both climate conditions and extreme events on wheat yields, price, and the global supply-demand chain.

Researchers from 13 worldwide institutes worked on the study, which finds that under 2 degrees Celsius warming, elevated carbon dioxide fertilization will compensate for the increased warming stresses, resulting in a 1.7 percent increase in global wheat yields.

However, the greater wheat yield will not result in a lower consumer price. According to the study, wheat yield is likely to increase at high latitudes and decrease at low latitudes. It will lead the grain prices to change unevenly, enhancing existing inequalities.

The model predicts that yields will increase in high latitude countries and regions, like the United States, Russia, and much of northern Europe. In countries like Egypt, India, and Venezuela, however, wheat yields are likely to drop in some areas by more than 15 percent.

"With this change in yields, the traditional trade position of the wheat market could deepen. This may cause the wheat-importing regions in low latitudes, such as Southern Asia and Northern Africa, to see more frequent and steeper wheat price spikes than wheat exporting countries," said lead researcher Zhang Tianyi with the Institute of Atmospheric Physics under the Chinese Academy of Sciences.

These changes further indicate that countries relying on wheat imports will pay more for a pivotal food crop in the future, and wheat prices on the global market will become more volatile and exacerbate existing inequalities.

They will also cause a wider income gap for farmers, lifting the income of wheat exporters but lowering that of importers, the study noted.

Zhang and his team hope that their predictions will prompt global action.

"Helping improve the grain food self-sufficiency in developing countries is crucial for global food security," he said. "This is worthy of discussion between countries in future international agricultural collaboration policy."