Beijing - Climate change and extreme weather events pose a grave challenge to the country's food supply, agricultural researchers have warned.

Gu Lianhong, a senior researcher with Oak Ridge National Laboratory in the US, said the lab's research had shown climate change will cause China's per capita grain output will dramatically drop after 2020, even taking technological progress into consideration.

The study suggests the projected geographical pattern of earth's surface temperature will dramatically increase in the late 21st century (2090-2099). This will cause more extreme weather and climate events to impact such industries as agriculture, Gu said.