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

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 is quantified using three coupled climate-chemistry models (CCMs). 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). In these 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). 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. 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. The surface O3 response to emission reductions is larger over the source region and smaller downwind in the future than under present-day conditions. 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.

DOHERTY R. M.;  WILD Oliver;  SHINDELL D. T.;  ZENG Guang;  MACKENZIE I. A.;  COLLINS W.J.;  FIORE A. M.;  STEVENSON D. S.;  DENTENER Franciscus;  SCHULTZ Martin;  HESS Peter;  DERWENT R.G.;  KEATING T.; 

2014-08-04

AMER GEOPHYSICAL UNION

JRC90925

2169-897X,   

http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50266/abstract,    https://publications.jrc.ec.europa.eu/repository/handle/JRC90925,   

10.1002/jgrd.50266,