This paper estimates carbon emissions from agricultural production in China’s Hunan Province during the period from 1998 to 2012. It also analyzes trends in the development of agricultural carbon emissions and the decoupling relationship between carbon emissions and the agricultural output of Hunan. In this study, emissions from two key segments of the agricultural sector were quantified: (1) crop production and (2) livestock and poultry production (singular). A combined method of principal component analysis (PCA), multiple regression analysis, and decoupling analysis was employed to assess the drivers of agricultural carbon emissions. This showed that there was a weak and unstable decoupling relationship between agricultural carbon emissions and their output value during the period of study. The PCA revealed that two main factors—urbanization rate and nitrogen fertilization per acre—explained 92.51 % of the variation in the 11 factors that affected carbon emissions from crops. Also, two main factors (i.e., agriculture per capita GDP and the ratio of beef production to total livestock production) explained 86.27 % of the variation in nine factors that affected carbon emissions from the livestock and poultry industry. Using the PCA scores as independent variables, a multiple regression analysis of carbon emissions from the crop industry and the livestock and poultry industry showed the following patterns. (1) Theoretically, given a 10 % reduction in nitrogen fertilization per acre, crop carbon emissions would decrease by 519 units. If the rate of urbanization were to increase by 1 %, crop carbon emissions would increase by 83 units;(2) similarly, a 1 % reduction in the beef: total livestock and poultry production ratio would reduce carbon emissions from that industry by 329 units, and with “agricultural per capita GDP”growth of 1 unit, those emissions would increase by 0.354 units. The results of this study contribute to evaluating the sustainability of agricultural production in the region, and they provide a foundation of knowledge for future development of related agricultural mitigation policy and low-carbon agricultural technology. ©2015, Springer-Verlag Berlin Heidelberg.