When the temperature rises, it is not too late to reduce the yield of wheat and cultivate new varieties.

If no adaptive measures are taken, global wheat production could be reduced by 6 per cent for every one degree Celsius rise in the future, which will reduce global production by 42 million tons, equivalent to one pound of the current global wheat trade volume.

Wheat plays an important role in feeding the global population. However, global climate change will threaten the bumper wheat harvest. If adaptive measures are not taken, total global wheat production is expected to decrease as temperatures rise.

The study, published in the high-impact journal Nature-Climate change, was carried out by an international research team and contributed significantly to the work of the Finnish Institute of Natural Resources.

Food production in most parts of the world is expected to decline as global climate temperatures rise, the study found. In 2012, global wheat production was 701 million tons, and every degree increase in temperature means that 4200 tons of wheat will be lost worldwide.

"in 2013, global wheat trading volume was 147 million tons, which, on the other hand, is equivalent to 1/4 of global wheat trading volume. In addition, the reduction in wheat production caused by climate change is higher than previously expected." Reimund R? a professor at the Finnish Institute of Natural Resources. "it should have been predicted earlier," Dr. tter said. "it should start when the temperature rises slightly."

When deciding how to take measures to deal with climate change, it is critical to understand how different climate factors interact and affect food production.

The researchers conducted field experiments and systematically tested 30 different wheat crop growth models. During the growing season, the temperature in the area where the experiment was carried out was between 15 and 26 degrees Celsius. Under the condition of field experiment, the effect of temperature on production reduction is very different. In addition, in some areas, crops increase in years with higher temperatures, while crop yields decrease in years with lower temperatures, which also increases year-on-year uncertainty.

"from the experience of recent years, it can be seen that from an economic point of view, the variability of yield is very important, which can affect the stability of regional and global wheat supply and food security, and amplify market and price fluctuations." Reimund R? Professor tter said.

The fifth assessment report released by the Intergovernmental Panel on Climate change predicts that the global average temperature will rise by 5 degrees Celsius by the end of the century.

"timely and appropriate responses, such as the cultivation of more heat-tolerant wheat varieties, may greatly reduce the risk of yield reduction caused by climate change." Reimund R? Tter emphasized.

Researchers from different countries participated in the collaborative study because of the Agricultural Model comparison and improvement Project (AgMIP). The Agricultural Model comparison and improvement Project is coordinated by Columbia University, National Aeronautics and Space Administration and the University of Florida. In addition to Finnish scientists, scientists from Germany, France, Denmark, the Netherlands, Spain, Britain, Colombia, Mexico, India, China, Australia, Canada and the United States are also involved in this global study.

In the study setting, the researchers first compared the experimental data of the simulated wheat crop growth model, including artificial heating and simulated multi-region field experiments. The researchers found changes between observations and simulations of individual growth models, and this deviation increased with the increase of temperature in the growing season.

The prediction results were calculated through the integration of multi-models, and based on the monitoring results, the scientists then applied the multi-models to calculate the wheat yield in the main growing areas of the world under the condition of rising temperature.