How Could Fire Emissions Reshape the Nitrogen Cycle?

Abstract Fire is a crucial process of the Earth's system and contributes to large emissions of carbon and nitrogen (N), including ammonia (NH 3 ) and nitrogen oxides (NO x ). Q. Chen et al. (2025, https://doi.org/10.1029/2024GL112396 ) reveals that extreme boreal fires emit unexpectedly high levels of NH 3 , comparable to large agricultural sources. The partitioning between NH 3 and NO x fire emissions varies across different ecosystem types, leading to divergent impacts on the N cycle. New advancements in Earth System Models and more specifically, a better representation of the N cycle would offer a powerful framework for enhancing our understanding of fire reactive nitrogen (N r ) emissions' impacts on atmospheric chemistry, ecosystems, and the global nitrogen cycle.