We’re not using our lands optimally: that is the message of a new study that shows where the world’s major food crops should be grown to maximise yield and minimise climate impacts. If fully incorporated, such a plan could theoretically cut the carbon impact of global crops by 71%, reversing 20 years’ worth of CO2 emissions.
So, how could changing the location of a crop change its environmental impact?
Under the imagined scenario, large new farming areas would be established around the US corn-belt and below the Sahara Desert, while huge areas of farmland in Europe and India would be restored to natural habitat.
The redesign would eliminate the need for irrigation by locating crops in places where rainfall provides the full complement of water needed to grow. Given agriculture is responsible for around 70% of the world’s freshwater use, this could drastically improve global drinking-water shortages.
Moreover, many areas of cropland used to be highly biodiverse ecosystems that could store masses of carbon in thick vegetation and rich soils.
“In many places, cropland has replaced natural habitat that contained a lot of carbon and biodiversity – and crops don’t even grow very well there,” explains study author Robert Beyer, formerly a researcher at the University of Cambridge’s Department of Zoology and now based at the Potsdam Institute for Climate Impact Research (PIK) in Germany. “If we let these places regenerate, and moved production to better suited areas, we would see environmental benefits very quickly.”
Of course, it’s not practical to literally relocate all the world’s crops, but the map does provide us with a vision of a more efficient and environmental way to use land. And even under its more conservative scenario of only relocating the worst-offending 25% of croplands within national borders, such efforts would still theoretically reverse around 10 years’ worth of emissions.
“It’s currently not realistic to implement this whole redesign,” says Beyer. “But even if we only relocated a fraction of the world’s cropland, focusing on the places that are least efficient for growing crops, the environmental benefits would be tremendous.”
By modelling climate impacts on landscape, the researchers found that the ideal locations for croplands will change very little until the end of the century, even as the climate changes.
“Optimal cropping locations are no moving target,” says senior author Andrea Manica, of the University of Cambridge. “Areas where environmental footprints would be low, and crop yields high, for the current climate will largely remain optimal in the future.”
But while this might seem an idealistic vision, how do you go about relocating croplands without disadvantaging farmers and causing economic upheaval?
One example the researchers cite is ‘set-aside’ schemes, in which farmers are paid to retire part of their land for environmental benefit.
It’s hard to imagine a world in which policymakers would opt for such a complex upheaval that alters the lives of millions; but as warming inches closer to 1.5°C, we may need all the inventive ideas we can get.
The research is published in Nature Communications Earth & Environment.