title: Global air quality and health co-benefits of mitigating near-term climate change through methane and black carbon emission controls.
abstract: BACKGROUND
  Tropospheric ozone and black carbon (BC), a component of fine particulate matter (PM ≤ 2.5 µm in aerodynamic diameter; PM(2.5)), are associated with premature mortality and they disrupt global and regional climate.
  
  
  OBJECTIVE
  We examined the air quality and health benefits of 14 specific emission control measures targeting BC and methane, an ozone precursor, that were selected because of their potential to reduce the rate of climate change over the next 20-40 years.
  
  
  METHODS
  We simulated the impacts of mitigation measures on outdoor concentrations of PM(2.5) and ozone using two composition-climate models, and calculated associated changes in premature PM(2.5)- and ozone-related deaths using epidemiologically derived concentration-response functions.
  
  
  RESULTS
  We estimated that, for PM(2.5) and ozone, respectively, fully implementing these measures could reduce global population-weighted average surface concentrations by 23-34% and 7-17% and avoid 0.6-4.4 and 0.04-0.52 million annual premature deaths globally in 2030. More than 80% of the health benefits are estimated to occur in Asia. We estimated that BC mitigation measures would achieve approximately 98% of the deaths that would be avoided if all BC and methane mitigation measures were implemented, due to reduced BC and associated reductions of nonmethane ozone precursor and organic carbon emissions as well as stronger mortality relationships for PM(2.5) relative to ozone. Although subject to large uncertainty, these estimates and conclusions are not strongly dependent on assumptions for the concentration-response function.
  
  
  CONCLUSIONS
  In addition to climate benefits, our findings indicate that the methane and BC emission control measures would have substantial co-benefits for air quality and public health worldwide, potentially reversing trends of increasing air pollution concentrations and mortality in Africa and South, West, and Central Asia. These projected benefits are independent of carbon dioxide mitigation measures. Benefits of BC measures are underestimated because we did not account for benefits from reduced indoor exposures and because outdoor exposure estimates were limited by model spatial resolution.
authors.affiliation: U.S. Environmental Protection Agency, Washington, DC 20460, USA. anenberg.susan@epa.gov
authors.forename: Susan C
authors.initials: SC
authors.lastname: Anenberg
authors.forename: Joel
authors.initials: J
authors.lastname: Schwartz
authors.forename: Drew
authors.initials: D
authors.lastname: Shindell
authors.forename: Markus
authors.initials: M
authors.lastname: Amann
authors.forename: Greg
authors.initials: G
authors.lastname: Faluvegi
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Klimont
authors.forename: Greet
authors.initials: G
authors.lastname: Janssens-Maenhout
authors.forename: Luca
authors.initials: L
authors.lastname: Pozzoli
authors.forename: Rita
authors.initials: R
authors.lastname: Van Dingenen
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Vignati
authors.forename: Lisa
authors.initials: L
authors.lastname: Emberson
authors.forename: Nicholas Z
authors.initials: NZ
authors.lastname: Muller
authors.forename: J Jason
authors.initials: JJ
authors.lastname: West
authors.forename: Martin
authors.initials: M
authors.lastname: Williams
authors.forename: Volodymyr
authors.initials: V
authors.lastname: Demkine
authors.forename: W Kevin
authors.initials: WK
authors.lastname: Hicks
authors.forename: Johan
authors.initials: J
authors.lastname: Kuylenstierna
authors.forename: Frank
authors.initials: F
authors.lastname: Raes
authors.forename: Veerabhadran
authors.initials: V
authors.lastname: Ramanathan
mesh_terms: D000397:Air Pollution / Q000517:prevention & control*; D057231:Climate Change; D003198:Computer Simulation; D004781:Environmental Exposure; D006801:Humans; D008697:Methane / Q000009:adverse effects / Q000032:analysis*; D008962:Models, Theoretical; D010126:Ozone / Q000009:adverse effects / Q000032:analysis*; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis*; D011634:Public Health / Q000706:statistics & numerical data*; D053260:Soot
chemical_list: D052638:Particulate Matter; D053260:Soot; D010126:Ozone; D008697:Methane