Global warming, grain production and its efficiency: Case study of major grain production region

摘要

Historical records and multiple researches have indicated that there is a close connection between carbon dioxide and surface temperature. Climate change and its impacts on agriculture, especially grain production, is one of the major challenges for food security and sustainable development. From the perspective of natural flow, climate change directly affects plant growth via water circulation, such as droughts and floods. Although the covariation of surface temperature and CO2 concentration will to some extent benefit crop photosynthesis, grain production may fluctuate according to the grain market, which is also affected by its erratic provisioning. We then determine how climate change affects grain production and efficiency using an input distance function and technical inefficiency model. First, we discover a significant relationship between surface temperature and grain production, although this impact is marginal; the coefficient is 0.0037 in the estimated model. Second, we find that surface temperature influences grain production not only through its photosynthesis but also its production efficiency in major grain production areas. And grain production efficiency is in a decreasing trend from 2000 to 2010, the average efficiency in 2010 is 0.75 on the whole. Third, there is a large gap in grain production efficiency among counties in Inner Mongolia, Hebei, Heilongjiang and Henan provinces, according to a distribution map of that efficiency.