Scientists around the world are rapidly pursuing various decarbonization strategies to reduce the impacts of climate change. However, some approaches risk intensifying other environmental challenges. One especially important system that is likely to be impacted by mitigation of greenhouse gas emissions is the global nitrogen cycle.
Nitrogen plays a dual and even contradictory role in current global systems. An essential part of agriculture and forestry commodity production, nitrogen serves as a critical input in the production of food, bioenergy and materials, as well as other key uses. Yet, too much reactive nitrogen contributes to air and water pollution as well as greenhouse gas production.
Xin Zhang, a professor at the Appalachian Laboratory (AL) of the University of Maryland Center for Environmental Science (UMCES) and director of the Global Nitrogen Innovation Center for Clean Energy and the Environment (NICCEE), collaborated with colleagues from AL, the U.S. Environmental Protection Agency, Carnegie Science, the Pacific Northwest National Lab, Delft University of Technology, the Chinese Academy of Sciences and Zhejiang University to produce the first comprehensive review of what is known about the potential trade-offs and synergies between decarbonization and the nitrogen cycle.
The results of the synthesis reveal that some decarbonization strategies, such as using ammonia as a fuel and crop-based biofuels, are likely to exacerbate environmental challenges associated with excess reactive nitrogen. Alternatively, reducing the use of nitrogen-based fertilizers with carbon-intensive production methods appears to be a win-win, mitigating both climate change and the negative environmental effects of reactive nitrogen. This study will guide future efforts to integrate nitrogen cycle management into climate change mitigation strategies, ensuring these efforts do not worsen the environmental challenges associated with reactive nitrogen.
"Improved understanding of these trade-offs and synergies is a key objective of the Global Nitrogen Innovation Center for Clean Energy and the Environment," said coauthor and UMCES Professor, Eric Davidson.
"Technological, socioeconomic and systemic changes across the agriculture–food–energy system are going to be needed to address climate change and nitrogen pollution together," Zhang said. "Doing so will help to ensure global food security and minimize environmental degradation as society reduces carbon dioxide emissions."
The research paper, entitled, "Nitrogen management during decarbonization," was published on September 10, 2024, in Nature Reviews Earth and Environment; it includes detailed visualizations describing the interactions between decarbonization and the nitrogen cycle. This research was supported by the National Science Foundation and the Belmont Forum.
