Background
The authors write that "rice is an essential component of the diet in more than half the world's population, and it is the most socially and economically important crop in China," where they say it "contributes 43.7% of total national grain production," citing the work of Yao et al. (2007).

What was done
Xiong et al. "assessed the effect of greenhouse gas-induced climate change, as well as the direct fertilization effect of CO2, on rice yields and production in China," by coupling "the regional climate model PRECIS (Providing Regional Climates for Impacts Studies) with the CERES (Crop Environment Resources Synthesis) rice crop model to simulate current (1961-1990) and future (2011-2100) rice yields and production under [the] A2 and B2 climate change scenarios" of the IPCC (Intergovernmental Panel on Climate Change).

What was learned
The four researchers report that with anticipated climate changes, "single rice cropping may expand further north in China, and double rice cropping may move to the northern portion of the Yangtze River basin." In addition, they say that "the national mean rice production is estimated to increase by 2.7 to 19.2% considering the combined effects of climate change, CO2 and shifting rice-producing areas."

What it means
Even considering the overly-inflated temperature increases predicted by the IPCC, the estimated net effect of global warming and concomitant growth in anthropogenic CO2 emissions ends up producing an increase in rice production in the world's most populated country, where it is the people's single most important food source. This is a blessing that simply cannot be ignored.

Reference
Yao, F.M., Xu, Y.L., Lin, E.D., Yokozawa, M. and Zhang, J.H. 2007. Assessing the impacts of climate change on rice yields in the main rice areas of China. Climatic Change 80: 395-409.