High-latitude vegetation changes will determine future plant volatile impacts on atmospheric organic aerosols

Abstract

Strong, ongoing high-latitude warming is causing changes to vegetation composition and plant productivity, modifying plant emissions of biogenic volatile organic compounds (BVOCs). In the sparsely populated high latitudes with clean background air, climate feedback resulting from BVOCs as precursors of atmospheric aerosols could be more important than elsewhere on the globe. Here, we quantitatively assess changes in vegetation composition, BVOC emissions, and secondary organic aerosol (SOA) formation under different climate scenarios. We show that warming-induced vegetation changes largely determine the spatial patterns of future BVOC impacts on SOA. The northward advances of boreal needle-leaved woody species result in increased SOA optical depth by up to 41%, causing cooling feedback. However, areas with temperate broad-leaved trees replacing boreal needle-leaved trees likely experience a large decline in monoterpene emissions and SOA formation, causing warming feedback. We highlight the necessity of considering warming-induced vegetation shifts when assessing land radiative feedback on climate following the BVOC-SOA pathway.