An agrarian crisis is brewing because of climate change that could jeopardise global food supplies and increase the risk of hunger for a billion poorest of the poor, scientists are warning.

South Asia and Africa would be hardest hit by the crisis, which would shift the world’s priorities away from boosting food output year after year to bolstering the resilience of crops to cope with warm weather, they said.

Rice, the staple for billions of people, is most vulnerable to global warming, said Dyno Keatinge, deputy director general of research at the International Crops Research Institute for the Semi-Arid Tropics.

“It is the world’s most consumed crop and it makes everything else pale in comparison,” Keatinge told reporters in Hyderabad, southern India, where the research institute has organised a conference on the impact of climate change on farming.

The rice yield could fall “very quickly in a warmer world” unless researchers find alternative varieties or ways to shift the time of rice flowering, he added, demanding governments allocate more money to research.

“We have the opportunity to grow other crops that are more resistant to higher temperatures such as sorgum and millet, but changing people’s food habits is very difficult”, he said.