State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing 100875, China.
Environ Sci Technol. 2021 Nov 2;55(21):14546-14555. doi: 10.1021/acs.est.1c03612. Epub 2021 Oct 22.
Croplands are the largest anthropogenic source of nitrous oxide (NO), a powerful greenhouse gas that contributes to the growing atmospheric NO burden. However, few studies provide a comprehensive depiction of future cropland-NO emissions on a national scale due to a lack of accurate cropland prediction data. Herein, we present a newly developed distributed land-use change prediction model for the high-precision prediction of national-scale land-use change. The high-precision land-use data provide an opportunity to elucidate how the changes in cropland area will affect the magnitude and spatial distribution of NO emissions from China's croplands during 2020-2070. The results showed a declining trend in China's total cropland-NO emissions from 0.44 ± 0.03 Tg N/year in 2020 to 0.39 ± 0.07 Tg N/year in 2070, consistent with a cropland area reduction from (1.78 ± 0.02) × 10 ha to (1.40 ± 0.15) × 10 ha. However, approximately 31% of all calculated cities in China would emit more than the present level. Furthermore, different land use and climate change scenarios would have important impacts on cropland-NO emissions. The Grain for Green Plan implemented in China would effectively control emissions by approximately 12%.
耕地是一氧化二氮（NO）的最大人为排放源，NO 是一种强大的温室气体，导致大气中 NO 负担不断增加。然而，由于缺乏准确的耕地预测数据，很少有研究能够全面描述未来耕地-N0 排放的情况。在此，我们提出了一种新的分布式土地利用变化预测模型，用于高精度预测全国范围内的土地利用变化。高精度的土地利用数据提供了一个机会，可以阐明耕地面积的变化将如何影响中国耕地在 2020-2070 年期间 NO 排放的规模和空间分布。结果表明，中国耕地-N0 排放总量呈下降趋势，从 2020 年的 0.44±0.03Tg N/年降至 2070 年的 0.39±0.07Tg N/年，与耕地面积从（1.78±0.02）×104ha 减少到（1.40±0.15）×104ha 相一致。然而，中国约有 31%的城市计算出的排放量将超过目前的水平。此外，不同的土地利用和气候变化情景将对耕地-N0 排放产生重要影响。中国实施的退耕还林还草计划将有效控制约 12%的排放量。
