Department of Land Management, Zhejiang University , Hangzhou 310058, People's Republic of China.
Policy Simulation Laboratory, Zhejiang University , Hangzhou 310058, People's Republic of China.
Environ Sci Technol. 2017 Nov 7;51(21):12089-12096. doi: 10.1021/acs.est.7b02171. Epub 2017 Oct 19.
China is a global hotspot of atmospheric ammonia (NH) emissions and, as a consequence, very high nitrogen (N) deposition levels are documented. However, previous estimates of total NH emissions in China were much lower than inference from observed deposition values would suggest, highlighting the need for further investigation. Here, we reevaluated NH emissions based on a mass balance approach, validated by N deposition monitoring and satellite observations, for China for the period of 2000 to 2015. Total NH emissions in China increased from 12.1 ± 0.8 Tg N yr in 2000 to 15.6 ± 0.9 Tg N yr in 2015 at an annual rate of 1.9%, which is approximately 40% higher than existing studies suggested. This difference is mainly due to more emission sources now having been included and NH emission rates from mineral fertilizer application and livestock having been underestimated previously. Our estimated NH emission levels are consistent with the measured deposition of NH (including NH and NH) on land (11-14 Tg N yr) and the substantial increases in NH concentrations observed by satellite measurements over China. These findings substantially improve our understanding on NH emissions, implying that future air pollution control strategies have to consider the potentials of reducing NH emission in China.
中国是全球大气氨（NH）排放的热点地区，因此有大量文献记录了高氮（N）沉积水平。然而，先前对中国总 NH 排放量的估计远低于根据观测到的沉积值推断的结果，这突出表明需要进一步调查。在这里，我们根据质量平衡方法重新评估了 2000 年至 2015 年中国的 NH 排放情况，该方法通过氮沉积监测和卫星观测进行了验证。中国的总 NH 排放量从 2000 年的 12.1 ± 0.8 Tg N yr 增加到 2015 年的 15.6 ± 0.9 Tg N yr，年增长率为 1.9%，比现有研究表明的要高约 40%。这种差异主要是由于现在纳入了更多的排放源，并且以前低估了矿物肥料施用和畜牧业的 NH 排放率。我们估计的 NH 排放水平与 NH（包括 NH 和 NH）在陆地上的测量沉积量（11-14 Tg N yr）以及卫星观测到的中国 NH 浓度的大幅增加一致。这些发现大大提高了我们对 NH 排放的理解，这意味着未来的空气污染控制策略必须考虑到减少中国 NH 排放的潜力。
