Anthropogenic-driven perturbations on nitrogen cycles and interactions with climate changes

Anthropogenic activities have substantially perturbed the global nitrogen (N) cycle directly through enhancing reactive N (Nr) inputs and indirectly through climate and land-use change. However, the climatic impacts of the N cycle and its feedbacks on climate change remain very uncertain. In this review, we provide an overview of the dominant pathways by which anthropogenic Nr affects the climate system and summarize the available scientific assessments. We also review the latest progress on the responses of N cycle to changing climate to understand the potential for feedbacks between the N cycle and climate. With the urgent need to reduce Nr in the future to alleviate its negative environmental impacts, e.g. air pollution and eutrophication, we highlight the importance for bridging disciplines of atmospheric chemistry, ecology, and climatology to improve the scientific understanding and develop cobenefits for both environmental protection and climate change mitigation.