Revolutionizing Climate Models with Nitrogen-Centric Aerosol Insights

**A collaborative research effort led by the Hong Kong University of Science and Technology (HKUST), Southern University of Science and Technology (SUSTech), and the National Center for Applied Mathematics Shenzhen (NCAMS) has introduced a new nitrogen-centric framework to better understand the light-absorbing effects of atmospheric organic aerosols.** Published in the journal *Science*, this study marks a major step forward in climate science by identifying nitrogen-containing compounds, specifically referred to as brown nitrogen (BrN), as critical in absorbing sunlight. This contrasts with traditional carbon-centric models, which have been less effective in capturing the true nature of how organic aerosols operate within the atmosphere. **Organic aerosols impact climate primarily through their interactions with sunlight, particularly by absorbing and scattering it in the near-ultraviolet and visible spectrums.** However, due to their complex and evolving chemical compositions, accurately assessing their climate effects has been notoriously challenging. **The study, spearheaded by Prof. FU Tzung-May and Prof. YU Jianzhen, suggests that BrN accounts for approximately 70% of the global light-absorbing effects of organic aerosols, contributing an average direct radiative effect of 0.034 watts per square meter.** This dominance in light absorption by BrN highlights the importance of nitrogen’s chemical evolution as a key driver for spatial and temporal variations in aerosol impact. **The implications of this finding are profound, especially as global climate change leads to more wildfires, which are likely to increase the emissions of BrN aerosols.** This introduces a positive feedback loop that could exacerbate climate warming, underscoring the need for updated climate and air quality models that incorporate nitrogen-centric data. **Prof. Yu emphasizes the necessity of understanding the interactions between these nitrogenous compounds and the broader climate system to enhance atmospheric models and develop effective pollution control strategies.** This research not only reshapes current scientific perspectives on organic aerosol absorption but also aids in crafting more precise climate change mitigation strategies.