Last updated October 10, 2018

Impacts of climate change on surface ozone and intercontinental ozone pollution: A multi-model study

  • Quantifies the impact of climate change between 2000 and 2095 SRES A2 climates on surface ozone (O)3 and on O3 source-receptor (S-R) relationships using three coupled climate-chemistry models (CCMs)
  • Finds the CCMs exhibit considerable variability in the spatial extent and location of surface O3 increases that occur within parts of high NOx emission source regions (up to 6 ppbv in the annual average and up to 14 ppbv in the season of maximum O3)
  • Finds that in high NOx emission source regions, all three CCMs show a positive relationship between surface O3 change and temperature change 
  • Sensitivity simulations show that a combination of three individual chemical processes—(i) enhanced PAN decomposition, (ii) higher water vapor concentrations, and (iii) enhanced isoprene emission—largely reproduces the global spatial pattern of annual-mean surface O3 response due to climate change (R2 = 0.52)
  • Finds that changes in climate are found to exert a stronger control on the annual-mean surface O3 response through changes in climate-sensitive O3 chemistry than through changes in transport as evaluated from idealized CO-like tracer concentrations
  • Finds all three CCMs exhibit a similar spatial pattern of annual-mean surface O3 change to 20% regional O3 precursor emission reductions under future climate compared to the same emission reductions applied under present-day climate
  • Finds the surface O3 response to emission reductions is larger over the source region and smaller downwind in the future than under present-day conditions
  • Results indicate that all three CCMs show areas within Europe where regional emission reductions larger than 20% are required to compensate climate change impacts on annual-mean surface O3