Shifts in the climate over the past three decades have been linked to a 5.5% decline in global wheat production, a study has suggested.
A team of US scientists assessed the impact of changes to rainfall and temperature on four major food crops: wheat, rice, corn and soybeans.
Climate trends in some countries were big enough to wipe out gains from other factors, such as technology, they said.
The findings have been published in the online edition of the journal Science.
“We focused on those four crops because they make up the bulk of calories consumed today,” said research leader David Lobell from Stanford University.
“There are already clear changes going on in most agricultural regions in terms of weather, and they have effects on food production that are sizeable,” he told the Science podcast.
“But in terms of temperature, we see that North America seems, oddly enough, to be exhibiting no real trend at all over the past 30 years.
“Whereas places like Europe, China and Brazil – pretty much the rest of the world, in terms of major agricultural production – have seen remarkable warming.”