Global crop varieties ‘can’t keep pace with climate change’

Crop yields around the world 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.

It takes anywhere between 10 and 30 years to breed a new crop variety and have it adopted by farmers.

However, global temperatures are rising faster than varieties can cope with and by the time these crops arrive in the field, they are being grown in much warmer temperatures than they were developed in.

See also: Global warming threat to wheat yields

The research, led by the University of Leeds and published on Tuesday (21 June) in the journal Nature Climate Change, focuses on maize in Africa, but the underlying processes affect crops across the tropics.

Scientists analysed the effects of rising temperatures on crop duration, which is the length of time between planting and harvesting.

They found higher temperatures meant shorter durations and therefore less time for crops to accumulate biomass that could result in lower yields.

The researchers found 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.

The research team, comprising experts in agriculture, climate and social science, looked at the options for ensuring that crops can be developed and delivered to the field more quickly.

These range from improved biochemical screening techniques to more socially centered measures such as improving government policies on breeding trials and farmers’ access to markets.

Invest in new seed technologies

“Investment in agricultural research to develop and disseminate new seed technologies is one of the best investments we can make for climate adaptation,” said Andy Jarvis, from the International Centre for Tropical Agriculture.

“Climate funds could be used to help the world’s farmers stay several steps ahead of climate change, with major benefits for global food security.”

The researchers have also proposed an alternative plan: use global climate models to determine future temperatures, then heat greenhouses to those temperatures and develop new crop varieties there.

Lead author Andy Challinor, from the Priestley International Centre for Climate at the University of Leeds, said: “The challenge here is in knowing what future emissions will be and ensuring climate models can produce accurate enough information on future temperatures based on those emissions.

“At the Priestley Centre, researchers are working on these challenges by improving climate models and targeting their use directly at solving such problems.”

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