For every degree Celsius that average temperatures increase, the world stands to lose 6 percent of its wheat crop.

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These are the findings of a new global study published last month in scientific journal Nature Climate Change. Senthold Asseng, a professor of Agricultural and Biological Engineering at the University of Florida, said the projected drop is equal to a quarter of the annual global wheat trade, which reached 147 million tons in 2013.

Prof Asseng used computer modelling to assess the impact of temperature increases on world wheat production. Asseng led a group of 50 scientists from 15 countries in pooling expertise to make incredibly accurate predictions.

"We started this with wheat, as wheat is one of the world's most important food crops," The professor said. "The simulations with the multi-crop models showed that warming is already slowing yield gains… at a majority of wheat-growing locations across the globe… despite observed yield increases in the past."

Worldwide, wheat accounts for 20 percent of the calories we consume. It is one of a very small number of staple crops that, together, make up more than 50 percent of the calorific intake of the world's population. Prof Asseng said his team's findings suggest that rising temperatures will massively frustrate efforts to produce enough food to feed an anticipated population of more than 9 billion people.

The professor added that, for 20 years, scientists have been trying to estimate the effects of temperature increase and climate change on various crops, including on wheat production. However, different research groups have come up with different results. The University of Florida scientist said that, by pooling various computer models used, he and his colleagues could predict changes more accurately.

The group of scientists worked with 30 wheat crop models and tested them against field experiments. In those experiments, average season temperatures ranged from 15 to 32 degrees Celsius.

Over the past 100 years, global temperatures have risen by more than 0.6 degrees and are projected to increase by 2 to 4 degrees Celsius by the end of the century, according to the International Panel on Climate Change (IPCC).

Prof Asseng said that models such as the one developed by his team will be necessary for informing choices on how to react to climate change. He said more heat tolerant cultivars and better management practices will be needed to avoid the declines anticipated in his work.