Asian aerosols: current and year 2030 distributions and implications to human health and regional climate change.

Aerosol distributions in Asia calculated over a 4-year period and constrained by satellite observations of aerosol optical depth (AOD) are presented. Vast regions in Asia that include > 80% of the population have PM2.5 concentrations that exceed on an annual basis the WHO guideline of 10 microg/m3, often by factors of 2 to 4. These high aerosol loadings also have important radiative effects, causing a significant dimming at the surface, and mask approximately 45% of the warming by greenhouse gases. Black carbon (BC) concentrations are high throughout Asia, representing 5-10% of the total AOD, and contributing significantly to atmospheric warming (its warming potential is approximately 55% of that due to CO2). PM levels and AODs in year 2030, estimated based on simulations that consider future changes in emissions, are used to explore opportunities for win-win strategies built upon addressing air quality and climate change together. It is found that in 2030 the PM2.5 levels in significant parts of Asia will increase and exacerbate health impacts; but the aerosols will have a larger masking effect on radiative forcing, due to a decrease in BC and an increase in SO2 emissions.

[1]  H. Ueda,et al.  MICS-Asia II: Model intercomparison and evaluation of particulate sulfate, nitrate and ammonium , 2008 .

[2]  J. Seinfeld,et al.  Three-dimensional simulations of inorganic aerosol distributions in east Asia during spring 2001 , 2004, Journal of Geophysical Research.

[3]  V. Ramanathan,et al.  Global anthropogenic aerosol direct forcing derived from satellite and ground-based observations , 2005 .

[4]  Michael D. King,et al.  Deep Blue Retrievals of Asian Aerosol Properties During ACE-Asia , 2006, IEEE Transactions on Geoscience and Remote Sensing.

[5]  S. Yoon,et al.  Influences of relative humidity on aerosol optical properties and aerosol radiative forcing during ACE-Asia , 2006 .

[6]  J. Penner,et al.  Aerosol direct radiative effects over the northwest Atlantic, northwest Pacific, and North Indian Oceans: estimates based on in-situ chemical and optical measurements and chemical transport modeling , 2005 .

[7]  David G. Streets,et al.  Dissecting Future Aerosol Emissions: warming Tendencies and Mitigation Opportunities , 2007 .

[8]  M. V. Ramana,et al.  Characterization of the seasonal cycle of south Asian aerosols: A regional‐scale modeling analysis , 2007 .

[9]  Glenn E. Shaw,et al.  Indian Ocean Experiment: An integrated analysis of the climate forcing and effects of the great Indo-Asian haze , 2001 .

[10]  V. Ramanathan,et al.  A regional scale chemical transport modeling of Asian aerosols with data assimilation of AOD observations using optimal interpolation technique , 2008 .

[11]  Young-Joon Kim,et al.  An overview of ACE‐Asia: Strategies for quantifying the relationships between Asian aerosols and their climatic impacts , 2003 .

[12]  G. Carmichael,et al.  Asian emissions in 2006 for the NASA INTEX-B mission , 2009 .

[13]  V. Ramanathan,et al.  Atmospheric Brown Clouds : Regional Assessment Report with Focus on Asia , 2008 .

[14]  V. Ramanathan,et al.  Global and regional climate changes due to black carbon , 2008 .

[15]  D. Streets,et al.  The importance of China's household sector for black carbon emissions , 2005 .

[16]  Michael Q. Wang,et al.  An inventory of gaseous and primary aerosol emissions in Asia in the year 2000 , 2003 .

[17]  P. S. Praveen,et al.  Atmospheric brown clouds: Hemispherical and regional variations in long‐range transport, absorption, and radiative forcing , 2007 .

[18]  Tami C. Bond,et al.  On the future of carbonaceous aerosol emissions , 2004 .

[19]  J. Randerson,et al.  Interannual variability in global biomass burning emissions from 1997 to 2004 , 2006 .

[20]  W. Collins,et al.  Simulating aerosols using a chemical transport model with assimilation of satellite aerosol retrievals: Methodology for INDOEX , 2001 .

[21]  G Habib,et al.  Residential Biofuels in South Asia: Carbonaceous Aerosol Emissions and Climate Impacts , 2005, Science.

[22]  D. Koch,et al.  Linking future aerosol radiative forcing to shifts in source activities , 2007 .