More droughts on the horizon for Europe’s farmers

Side-effects of global climate change will include frequent heatwaves and prolonged droughts across Europe, as happened last summer, triggering possible crop failures. Understanding how staple crops respond to increased temperatures is a must if we are to mitigate looming threats of food shortages.

Enter an international team of scientists, who have published their findings in the journal Nature Communications based on their modelling of how various staple crops would do in the face of drought and heat stress brought on by climate change.

The researchers employed 10 different models to calculate how much either heat or drought would contribute to yield losses in two crops in the period up to 2050: maize and winter wheat. They then compared the model results with yield data during a quarter century between 1984 and 2009 in order to quantify how much these climatic factors contributed to the variations in yields in that period.

Their results are in: while maize would have lower yields, winter wheat would have higher ones. In other words, whereas some plants would benefit, others would lose out.

“Across Europe, on average heat stress does not increase for either crop in rainfed systems, while drought stress intensifies for maize only,” the researchers write. “In low-yielding years, drought stress persists as the main driver of losses for both crops, with elevated CO2 offering no yield benefit in these years.”

Such knowledge can be key in equipping farmers with the tools to mitigate the effects of climate change on their crops. By understanding whether heat or drought poses the greatest risk to specific types of crops, farmers and plant breeders can better select crop varieties and management systems to militate against the effects of changing weather conditions on their yields, the scientists say.

“Our results show that in Europe drought will be a bigger problem than heat, and that drought is a bigger problem for maize than wheat,” says Professor Jørgen E. Olesen from the Department of Agroecology at Aarhus University in Denmark. “This means that it will be less attractive than expected for Danish farmers to switch from wheat to maize as the climate warms up.”