Impacts of Climate Change on Maize Production in China and the U.S. and Possible Risk Mitigation Strategies

by Xiang Li

Institution: University of Tokyo
Year: 2013
Keywords: climate change, maize production, interrelationship, climate and socioeconomic inputs, risk, mitigation
Record ID: 1236509
Full text PDF: http://hdl.handle.net/2261/55465


It has become increasingly clear among scientists that a continuous increase in atmospheric greenhouse emission is changing the climate of earth. Among various climate change sensitive ecosystem, agriculture is a key sector to support the sustainable economic development of our society in this century. Given the backdrop of the fact that the share of maize production in China and the U.S. is over 50% of total maize production amount in the world, this thesis analyzed the interrelationship between climate change and maize production in China and the U.S. with a multidisciplinary approach, predicted the potential effects of climate change on maize production, and proposed alternative risk mitigation strategies to reduce the whole-country risk of maize reduction. This thesis did three case studies in China and the U.S., where climate inputs, socioeconomic inputs, and technology improvement (with and without) were taken into the consideration. While the first study analyzed the maize production in the Midwestern United States and Middle China with a semi-optimized supply function, the following two studies separately analyzed maize production responses in the North and the South of two countries with a regression function (Cobb-Douglas production function) and converted supply functions. The major finding of the first case study is that climate change will not universally cause negative impacts of maize yields in the United States and China. The results of a simulation of climate change on maize yields over the period 2008–2030 showed that variation in regional climatic and economic conditions could make the impacts of climatic change on maize yields substantially different in different regions. Even with significant changes in climate conditions that alter the maize crop‟s growing environment and affect crop yields, a decrease in maize supply due to a decrease in maize yields would lead to an increase in the maize price, which in turn would induce farmers to add more investments in production inputs to raise yields. Thus, the decrease in actual yields may not be as dramatic as predicted in cases where only climate factor are considered. The second study indicates that the impacts on maize production will likely be the opposite in the Northeast and the Southwest of China. The results indicate that a higher flexibility of production timing in the Southwest region allows farmers to better adapt to climate change than the Northeast region. Moreover, the gains in the Southeast may outweigh the potential reduction of maize production in the Northeast region. When a further reduction of agricultural labor population occurs, maize production decreases more in the Southwest region, even the substitution of more machinery for human labor is allowed. This result reflects that terraced, sloped lands in the Southwest region limit the effective use of machinery. The third case study indicates that under the same climate change South region tends to respond oppositely relative to the North Central region in the U.S., implying that one…