Global Warming Reducing Temperature Stress on Chinese Rice

Published December 22, 2011

Global warming is benefiting rice production in China, the world’s leading rice producer, Chinese scientists report in the peer-reviewed journal Agricultural and Forest Meteorology. The study by scientists at Nanjing Agricultural University and the Chinese Academy of Sciences found global warming is causing no increase in high-temperature stress on rice plants and is reducing the frequency and severity of low-temperature stress.

Critical Food Crop
“Rice is the most important food in the diets of Asians, Africans and Latin Americans; in fact, it serves as a basic staple for more than half of the world’s population,” the scientists stated in the study. Chinese rice production is particularly important, the scientists noted, because China accounts for 29 percent of global rice production.

Warmer Temps, Less Stress
The scientists examined temperature records and temperature-related stress on rice plants from 1961 to 2008. “China has experienced significant global warming over the last five decades,” they reported. “The annual mean air temperature has increased by 1.2 degrees C[elsius] since 1960.”

As temperatures warmed, “Our results suggest that global warming over the period 1961-2008 did not increase high-temperature stress but did reduce low-temperature stress in irrigated rice across China,” the study stated.

Production Benefits
Rice plants directly benefited from this reduction in temperature-related stress as the planet warmed. “Extreme temperatures are destructive to rice growth and, hence, critical to development of rice productivity,” the study observed.

“Temperature is a principal factor affecting rice growth, development and grain yield production. Warming tends to shift rice phenology and to extend the length of the growing season, allowing for earlier planting and later harvesting,” the scientists observed.

Chinese and global rice production have reached record levels in recent years. “Our results suggest that the indices of low- or high-temperature stress can be used to explain the year-to-year changes in rice yield,” the scientists concluded.

James M. Taylor ([email protected]) is managing editor of Environment & Climate News.

Internet Info:

“The Effect of a Half-Century of Warming on China’s Irrigated Rice,” NIPCC Report, http://www.nipccreport.org/articles/2011/nov/9nov2011a4.html

“Global warming over the period 1961-2008 did not increase high-temperature stress but did reduce low-temperature stress in irrigated rice across China,” Agricultural and Forest Meteorology, http://www.sciencedirect.com/science/article/pii/S0168192311001225