University of Florida researchers have demonstrated for the first time that wheat production models that predict yields for the world's most valuable commercial crop begin to disagree under different climate change scenarios.
The discovery is vitally important to future world food production, say the scientists at UF's Institute of Food and Agricultural Sciences, because by knowing where wheat production models break down, they and their peers around the world will be better able to improve them.
The computerized models are used by commercial wheat producers to predict crop yields. Scientists use them to foresee which parts of the world might face the worst food shortages in the future, so that policymakers and others can increase efforts to improve food production in affected areas.
The IFAS researchers analyzed the effectiveness of 27 wheat production models created by top scientists from around the world under both normal and climate change conditions. The results were reported in the June issue of Nature Climate Change.
The key finding of the latest research is that when scientists begin to manipulate climate data based on predictions of how climate change will play out over the next 50 to 100 years, the models start to disagree more and more, said Senthold Asseng, lead author of the study and an associate professor in IFAS's agricultural and biological engineering department. "And they start to disagree particularly with increasing temperatures and carbon dioxide."
That discovery, Asseng said, "shows us that we do not yet fully understand how temperature and crop production actually [impact one another]. So one of the big challenges now is to better understand how crop production systems work in relation to temperature, carbon dioxide in the environment, and water supply."
In the future, Asseng said, climate change will have a significant impact on global food production. "And that's where good crop models come into play," he said. "They are very important tools for understanding the impact of climate change on food production, including wheat production."
Wheat, which is one of the world's three most important crops, along with corn and rice, accounts for 20 percent of the calories consumed globally. World trade in wheat is greater than all other crops combined.
Accurate, reliable models that can assess the impact of climate change on production are critical to the future ability to feed the world's growing population, Asseng said.
Such improved capability is also important to the world's policymakers so they can "get an understanding of where the hot spots in the world will be in the future.' he said. "They also must understand how climate change might impact global production and where there might be food shortages in the future. And we need better models to be able to predict those things and be prepared for the impact of climate change."
The ongoing research is being done as part of the Agricultural Model Intercomparison and Improvement Project (AgMIP), an international effort to assess crop models and better understand the impact of climate change in worldwide food production.
UF is one of three organizations, along with the NSAS Goddard Institute for Space Studies in New York and U.S. Department of Agriculture, leading the AgMIP initiative.
Asseng and his UF colleagues have been working with an international team of scientists that over the last four decades have developed the science of crop production models.
In June, 50 scientists from 15 countries met in Mexico City to discuss UF's most recent research findings and coordinate future planning.
Jim Jones, an emeritus distinguished professor in IFAS's agricultural and biological engineering department, served as a co-author of the new study with Asseng, who also coordinated the research with co-author Frank Ewert, a professor with the Institute of Crop Science and Resource Conservation at the University of Bonn in Germany.
"As agricultural scientists," Jones said, "we need to have an understanding of how are food systems are going to respond to the future challenges associated with climate change."
The new research is an important step in that process. But much work remains to be done.