Emissions of non-CO2 greenhouse gases from livestock in China during 2000–2015: Magnitude, trends and spatiotemporal patterns

Livestock production, an important source for non-CO2 greenhouse gases (GHGs) including methane (CH4) and nitrous oxide (N2O) in China, has changed remarkably over the past decades due to economic development and demand for livestock product. However, the variation of non-CO2 GHGs from China's livestock have not received sufficient attention in existing literature. Here, we examine the spatiotemporal patterns of emissions of CH4 and N2O from main livestock in China as well as their long-term trends during the period 2000-2015. Results suggest that the livestock sourced emissions of non-CO2 GHGs in China experienced three phases: a rapid increase from 2000 to 2006, followed by a sharp drop in 2007 and then a slow increase at a lower level from 2008 to 2015. The 2007 drop reflects the impact of macro-control policies on livestock development and extensive measures taken on livestock to control the flu outbreak that year, and the slower increase from 2008 to 2015 with respect to the period 2000-2006 reflects the changes in livestock categories and a general improvement in production efficiency. Spatiotemporal patterns demonstrate that traditional livestock provinces including Henan, Sichuan, Inner Mongolia, Shandong, Yunnan and Hunan stood out as top six provinces in emission of non-CO2 GHGs in 2015. On the other hand, provinces like Jiangxi, Hubei, Hunan, Yunnan, Inner Mongolia, Liaoning and Xinjiang, identified as the emerging provinces, demonstrate the highest growth rates over the last decades. We find that different livestock categories dominated the difference in pattern of non-CO2 GHG emissions in both provinces with high emissions and those with high growth rates. Mitigation measures and policies suggestions should not only focus on high non-CO2 GHG emissions provinces, but also pay attention to the emerging new sources.