Air Quality and Climate Effects of Oil Palm Expansion in Southeast Asia 1990 - 2010

Abstract:

The natural rainforests of Southeast Asia have endured large-scale losses over the last few decades, principally driven by logging and agroforestry activities, including rapid expansion of plantations of high-isoprene-emitting oil palm (Elaeis guineensis) trees at the expense of comparatively low-emitting natural dipterocarp rainforests. Satellite-derived estimates of land cover represent snapshots in time of this highly-dynamic landscape. We apply multiple observational datasets and a global carbon-chemistry-climate model (NASA ModelE2-YIBs) to quantify the magnitude of altered biogenic volatile organic compound (BVOC) fluxes in Southeast Asia and the resulting impacts on atmospheric chemical composition due to the past two decades of land cover change in the region. NASA ModelE2-YIBs includes a fully interactive land carbon cycle. Isoprene production is energetically coupled to photosynthesis. Time-slice simulations for the period spanning 1990 – 2010 are forced with monthly anthropogenic and biomass burning emissions from the MACCity emissions inventory. Simulated tropospheric chemical composition is compared to observations, including fire-free formaldehyde columns, TES vertically-resolved ozone concentrations, and surface-level ozone measurements. We assess the contribution of land cover change-induced BVOC emission changes to regional ozone and aerosol pollution and provide the first estimate of the impacts on global climate.