Crop yields will fall within the next decade due to climate change unless immediate action is taken to speed up the introduction of new and improved varieties, experts have warned.
The research, led by the University of Leeds and published in the journal Nature Climate Change, focuses on maize in Africa but the underlying processes affect crops across the tropics.
Study lead author Professor Andy Challinor, from the Priestley International Centre for Climate at the University of Leeds, said: “In Africa, gradually rising temperatures and more droughts and heat waves caused by climate change will have an impact on maize.
“We looked in particular at the effect of temperature on crop durations, which is the length of time between planting and harvesting. Higher temperatures mean shorter durations and hence less time to accumulate biomass and yield.”
It takes anywhere between 10 and 30 years to breed a new crop variety and have it adopted by farmers. The rate at which temperatures are increasing across the tropics means that by the time the crop is in the field it is being grown in warmer temperatures than it was developed in.
By looking at a range of data on farming, regulatory policy, markets and technologies, the researchers developed average, best- and worst-case scenarios for current crop-breeding systems.
The researchers found that crop duration will become significantly shorter by as early as 2018 in some locations and by 2031 in the majority of maize-growing regions in Africa. Only the most optimistic assessment — in which farming, policy, markets and technology all combine to make new varieties in 10 years — showed crops staying matched to temperatures between now and 2050.