Unexpected response of nitrogen deposition to nitrogen oxide controls and implications for land carbon sink

Mingxu Liu; Fang Shang; Xingjie Lu; Xin Huang; Yu Song; Bing Liu; Qiang Zhang; Xuejun Liu; Junji Cao; Tingting Xu; Tiantian Wang; Zhenying Xu; Wen Xu; Wenling Liao; Ling Kang; Xuhui Cai; Hongsheng Zhang; Yongjiu Dai; Tong Zhu

doi:10.1038/s41467-022-30854-y

Unexpected response of nitrogen deposition to nitrogen oxide controls and implications for land carbon sink

Nat Commun. 2022 Jun 6;13(1):3126. doi: 10.1038/s41467-022-30854-y.

Authors

Mingxu Liu^#¹, Fang Shang^#¹, Xingjie Lu^#², Xin Huang³, Yu Song⁴, Bing Liu⁵, Qiang Zhang⁶, Xuejun Liu⁷, Junji Cao^{8

9}, Tingting Xu¹⁰, Tiantian Wang¹, Zhenying Xu¹, Wen Xu⁷, Wenling Liao¹, Ling Kang¹, Xuhui Cai¹, Hongsheng Zhang¹¹, Yongjiu Dai², Tong Zhu^{12

13}

Affiliations

¹ State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China.
² School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
³ Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, 210023, Nanjing, China.
⁴ State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China. songyu@pku.edu.cn.
⁵ Environmental Quality Forecast Center, China National Environmental Monitoring Center, 100012, Beijing, China.
⁶ Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Institute for Global Change Studies, Tsinghua University, 100084, Beijing, China.
⁷ Key Laboratory of Plant-Soil Interactions of MOE, Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, China Agricultural University, Beijing, 100193, China.
⁸ State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, 710061, Xi'an, China.
⁹ Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, 710061, Xi'an, China.
¹⁰ Department of Environmental Science and Engineering, College of Ecology and Environment, Chengdu University of Technology, Chengdu, 610059, China.
¹¹ Laboratory for Atmosphere-Ocean Studies, Department of Atmospheric and Oceanic Science, School of Physics, Peking University, 100871, Beijing, China.
¹² State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China. tzhu@pku.edu.cn.
¹³ Beijing Innovation Center for Engineering Science and Advanced Technology, Peking University, Beijing, 100871, China. tzhu@pku.edu.cn.

^# Contributed equally.

Abstract

Terrestrial ecosystems in China receive the world's largest amount of reactive nitrogen (N) deposition. Recent controls on nitrogen oxides (NO_x = NO + NO₂) emissions in China to tackle air pollution are expected to decrease N deposition, yet the observed N deposition fluxes remain almost stagnant. Here we show that the effectiveness of NO_x emission controls for reducing oxidized N (NO_y = NO_x + its oxidation products) deposition is unforeseen in Eastern China, with one-unit reduction in NO_x emission leading to only 55‒76% reductions in NO_y-N deposition, as opposed to the high effectiveness (around 100%) in both Southern China and the United States. Using an atmospheric chemical transport model, we demonstrate that this unexpected weakened response of N deposition is attributable to the enhanced atmospheric oxidizing capacity by NO_x emissions reductions. The decline in N deposition could bear a penalty on terrestrial carbon sinks and should be taken into account when developing pathways for China's carbon neutrality.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants* / analysis
Carbon Sequestration
China
Ecosystem
Environmental Monitoring
Nitric Oxide
Nitrogen Oxides
Nitrogen* / analysis

Substances

Air Pollutants
Nitrogen Oxides
Nitric Oxide
Nitrogen