The impact of residential combustion emissions on atmospheric aerosol, human health, and climate

Abstract

Abstract. Combustion of fuels in the residential sector for cooking and heating results in the emission of aerosol and aerosol precursors impacting air quality, human health, and climate. Residential emissions are dominated by the combustion of solid fuels. We use a global aerosol microphysics model to simulate the impact of residential fuel combustion on atmospheric aerosol for the year 2000. The model underestimates black carbon (BC) and organic carbon (OC) mass concentrations observed over Asia, Eastern Europe, and Africa, with better prediction when carbonaceous emissions from the residential sector are doubled. Observed seasonal variability of BC and OC concentrations are better simulated when residential emissions include a seasonal cycle. The largest contributions of residential emissions to annual surface mean particulate matter (PM 2.5 ) concentrations are simulated for East Asia, South Asia, and Eastern Europe. We use a concentration response function to estimate the human health impact due to long-term exposure to ambient PM 2.5 from residential emissions. We estimate global annual excess adult (> 30 years of age) premature mortality (due to both cardiopulmonary disease and lung cancer) to be 308 000 (113 300-497 000, 5th to 95th percentile uncertainty range) for monthly varying residential emissions and 517 000 (192 000-827 000) when residential carbonaceous emissions are doubled. Mortality due to residential emissions is greatest in Asia, with China and India accounting for 50 % of simulated global excess mortality. Using an offline radiative transfer model we estimate that residential emissions exert a global annual mean direct radiative effect between −66 and +21 mW m −2 , with sensitivity to the residential emission flux and the assumed ratio of BC, OC, and SO 2 emissions. Residential emissions exert a global annual mean first aerosol indirect effect of between −52 and −16 mW m −2 , which is sensitive to the assumed size distribution of carbonaceous emissions. Overall, our results demonstrate that reducing residential combustion emissions would have substantial benefits for human health through reductions in ambient PM 2.5 concentrations.

Global radiative effects of solid fuel cookstove aerosol emissions

“…Annual emissions of BC from global solid fuel cookstove sector in our study (2.3 Tg C yr −1 ) is approximately 44 % higher than that from the global biofuel emissions (1.6 Tg C yr −1 ) in Kodros et al (2015), which, to some extent, leads to differences in annual mean DRE values together with different optical calculations. The annual mean DRE value from another study by Butt et al (2016) differs from ours in magnitude and sign, and concluded that the annually averaged DRE from residential combustion sources was −5 mW m −2 (Fig. 10).…”

“…The negative effect of DRE in Butt et al (2016) is partially driven by the inclusion of SO 2 emissions (8.9 Tg SO 2 yr −1 ) from commercial coal combustion in the residential sector, leading to the cooling effect of sulfate and organic aerosols outweighing the warming from BC. The AIE in our control simulation is 38 times higher than that from Kodros et al (2015) and over an order of magnitude higher than that from Butt et al (2016). Consistent with our study, Ward et al (2012) also found a large AIE (−1.74 to 1.00 W m −2 ) for carbonaceous aerosols from fires using CESM CAM4-Chem.…”

“…The above changes in cookstove-emission-induced SW and LW AIE are caused by the substantial increases in high cloud Figure 10. Comparisons of DRE (left) and AIE (right) radiative effects from global solid fuel cookstove emissions in our control simulation with Kodros et al (2015) and Butt et al (2016).…”

“…Kodros et al (2015) have estimated that the net DRE of solid fuel aerosol emissions ranges from −20 to +60 m Wm −2 and the AIE from −20 to +10 m Wm −2 , with uncertainties due to assumptions of the aerosol emission masses, size distribution, aerosol optical properties and mixing states. Butt et al (2016) reported that the net DRE and AIE of aerosols from the residential emission sector (including coal) ranged from −66 to +21 mW m −2 and from −52 to −16 mW m −2 , respectively. Their study did not include greenhouse gases.…”

“…The possible scope for global climate co-benefits in future Indian cookstove intervention programs warrants further examination and analysis of this region. BC-rich household solid fuel emission plays an important role in affecting regional air quality (ArcherNicholls et al, 2016;Carter et al, 2016;Liu et al, 2016) and influencing global climate change (Bauer et al, 2010;Butt et al, 2016;Venkataraman et al, 2005). The human health consequences of solid fuel combustion are substantial (ArcherNicholls et al, 2016;Ezzati and Kammen, 2002;Lelieveld et al, 2015).…”