Crop Production Pushes up Greenhouse Gases Emissions in China: Evidence from Carbon Footprint Analysis Based on National Statistics Data

The rapid growth of crop yield in China was maintained by more fossil fuel inputs in the past years, causing concern about the greenhouse gas (GHG) emissions related to crop production. Therefore, this study analyzed historical dynamics of carbon footprint (CF) of 11 major crops in China during 2000–2016 and estimated possible GHG emissions of the system in 2020 under different scenarios. Results indicated that the GHG emissions of the Chinese crop system increased by 20.07% from 2000 to 2016, in which the grain crops contributed to more than 80% of the total emissions. The GHG emissions from grain crops including maize, wheat, and rice as well as sugar crops including sugarcane and sugar beet were increased by 28.07% and 14.27% in the study period, respectively, making up the primary factor of increased GHG emissions of crop system in China. Moreover, if the cropping pattern and agricultural practices is not improved in the future, the GHG emissions from Chinese crop system are estimated to increase by 346.19 million tons in 2020. If advanced agricultural policies and practices are implemented, the GHGs emissions of crop system in China in 2020 are estimated to be 2.92–12.62% lower than that in 2016. Overall, this study illustrated that the crop system in China contributed to the growth of GHG emissions in China over the past decades. Improving utilization efficiency of fertilizers and crop structure in China are the most important ways to reduce GHG emissions from the Chinese crop system.