Re-evaluating the climate impacts of sulfur emissions by developed and developing countries from the perspective of consumption

Abstract:

International trade allows consumption of any region to be supplied by production worldwide. This affects the magnitude and geographical pattern of consumption associated emissions, which differ greatly from those of emissions associated with regional production (as in a typical emission inventory). Yet the climate influence of aerosols emissions associated with regional consumption remains unknown, despite that understanding this issue offers crucial information to support policymaking and international cooperation in climate change mitigation action from a consumption perspective. Here we quantify for the first time the effects of sulfate aerosol associated with consumption of developed and developing countries on global temperature and precipitation, by integrating a most current-generation fully coupled Earth system model (CESM2), a recent multi-regional input-output table (GTAP) and an updated emission inventory for CMIP6 climate simulations (CEDS). We find that despite large emission differences between developed and developing countries, consumption associated sulfur emissions of both regions lead to comparable impacts on the global mean surface air temperature. This is due to 1) the difference between developed and developing countries in the spatial distribution of consumption associated sulfate, and 2) the response of the nonlinear climate system to the spatial pattern of aerosol forcing. We further discuss the regional patterns of temperature and precipitation responses to sulfur emissions. This study serves as the first step of a comprehensive assessment of the climate response to the whole suite of consumption associated pollutants (black carbon, organic carbon, sulfate, ozone, etc.), complementing prevailing regional attribution analyses of climate change based on production associated emissions and radiation forcing.