Climate change threatens food supplies if extreme weather conditions affect more than one grain-producing region at a time, scientists have warned.

Time is a key variable, and usually crop losses in one region are offset by that in another, which is aided by short-term storage and trading systems.

However, it is now "doubtful whether the current system is resilient to more extreme climatic conditions," a report published in the journal Nature Climate Change said.

A team from Austria-based International Institute for Applied Systems Analysis (IIASA) said climate change has not only led to higher temperatures but also led to more severe climate events such as drought, heat and floods.

“Climatic shocks to agricultural production contribute to food price spikes and famine, with the potential to trigger other systemic risks, including political unrest and migration,” IIASA lead author Franziska Gaupp said.

The IIASA study states that climate and yield data from 1967 to 2012 show "a significant increase in the probability of multiple global breadbasket failures for particularly wheat, maize, and soybeans."

One of the largest losses in soybean production was 7.2 million tonnes in 1988-89, the study noted, adding that if all major regions of cultivation of this crop were affected, the loss would be "at least 12.55 million tonnes. "

Separately, a study by the Economist Intelligence Unit of 113 countries on its Global Food Security Index (GFSI) showed that food prices are rising globally.

Singapore is ranked number one in global food security, followed by Ireland and the United States in a report that "highlights (the) need for innovation and investment in food systems to adapt to climate threats,” the EIU said.