Arctic expansion of boreal forests: can the BVOC emission impact rival the albedo effect?

As global surface temperatures continue to rise, vegetation is expected to adapt, with high-latitude forests projected to migrate northward into the Arctic regions. This shift will result in significant changes in land cover, influencing the climate through various biogeophysical and biogeochemical feedback mechanisms. While many studies have shown that changes in albedo drive substantial warming, a more comprehensive evaluation of the impacts associated with changes in Biogenic Volatile Organic Compound (BVOC) emissions is needed. Some studies suggest that BVOC-related effects could significantly influence climate in these pristine regions, potentially counteracting the albedo effect. BVOCs play a crucial role in atmospheric chemistry and aerosol formation; changes in their emissions can alter aerosol properties, subsequently affecting cloud characteristics and potentially leading to a cooling effect. In this study, we use the Norwegian Earth System Model v2 (NorESM2) with projected vegetation migration, running nested experiments under current climatic conditions and warmer climate forcing scenarios to assess the radiative forcing of BVOC-related impacts, in comparison with the albedo change. Preliminary findings suggest that under current climate conditions, BVOC-related impacts are insufficient to rival the warming effect of albedo changes; however, their relative role could be significantly amplified in warmer future climates.