Historical Trends and Controlling Factors of Isoprene Emissions in CMIP6 Earth System Models

作者：Thi Nhu Ngoc, Kengo Sudo, Akihiko Ito, L. K. Emmons, Vaishali Naïk, Kostas Tsigaridis, Øyvind Seland, Gerd Folberth, Douglas I. Kelley · 年份：2024 · DOI：10.5194/egusphere-2024-2313 · 被引用次数：3 · 研究领域：Atmospheric chemistry and aerosols、Atmospheric and Environmental Gas Dynamics、Plant responses to elevated CO2

Abstract. Terrestrial isoprene, a biogenic volatile organic compound emitted by many plants, influences atmospheric chemistry and the Earth’s radiative balance. Elucidating its historical changes is therefore important for predicting climate change and air quality. Isoprene emissions can respond to climate (e.g., temperature, shortwave radiation, precipitation), land use and land cover change (LULCC), and atmospheric CO2 concentrations. However, historical trends of isoprene emissions and the relative influences of the respective drivers of those trends remain highly uncertain. This study addresses uncertainty in historical isoprene emission trends and their influential factors, particularly the roles of climate, LULCC, and atmospheric CO2 (via fertilization and inhibition effects). The findings are expected to reconcile discrepancies among different modelling approaches and to improve predictions of isoprene emissions and their climate change effects. To investigate isoprene emission trends, controlling factors, and discrepancies among models, we analyzed long-term (1850–2014) global isoprene emissions from online simulations of CMIP6 Earth System Models and offline simulations using the VISIT dynamic vegetation model driven by climate reanalysis data. Mean annual global present-day isoprene emissions agree well among models (434–510 TgC yr⁻¹) with a 5 % inter-model spread (24 TgC yr⁻¹), but regional emissions differ greatly (9–212 % spread). All models show an increasing tr...