GAW Report No. 205 - IGAC Project

CHAPTER 1 - INTRODUCTIONIn addition to air pollution having an impact on radiative forcing, climate change has animpact on air pollution meteorology and chemical process. Projected changes in surfacetemperature and precipitation (Figure 10) due to radiative forcing caused by both long and shortlivedclimate forcers will impact regional air pollution. A strong warming occurs over the northernmid-latitude continents and no area shows cooling [Jacob and Winner, 2009]. The increase intemperature leads to an increased frequency of heat waves, which are strongly associated withhigh pollution episodes, e.g., the 2003 heat wave in Europe. Precipitation is expected to increasedue to increased evaporation from the oceans. However, the frequency and intensity of theincreased precipitation varies considerably at a regional scale. Less frequent but heavierprecipitation events could lead to more pollution episodes by reducing wet deposition of aerosoland other pollutants. Models also indicate a warming climate could impact large-scaleatmospheric dynamic patterns. For example, Leibensperger et al. [2008] show a significant longtermdecline in the number of summertime mid-latitude cyclones across the northeastern UnitedStates, which in turn strongly correlates with the number of high ozone episodes due to decreasedpollutant ventilation. It is now widely recognized that air pollution and climate change can nolonger be considered as separate issues in the scientific and policy communities [Tai et al.,2010].Figure 10 - Differences in annual mean surface temperatures and precipitation in Europe, Asia, and North America for 2080-2099 vs. 1980-1999 averaged over an ensemble of about 20 GCMs contributing to the IPCC 4 th Assessment[Jacob and Winner, 2009]1.3 HEALTH IMPACTS OF AIR POLLUTIONThere is great evidence linking air pollution with mortality and morbidity in the generalpopulation [Brunekreef and Forsberg, 2005; Zanobetti and Schwartz, 2005; Pope and Dockery,1996; Nawrot et al., 2006; Dominici et al., 2006; Barnett et al., 2006; Guaderman et al., 2007].Several physiopatological mechanisms of injury are described [Osornio-Vargas et al., 2003; Inoueet al., 2006;Yeatts et al.,2007; Sakamoto et al., 2007; Barlowet al., 2007]. Public health damage isconsistently found with adverse effects concentrated in urban areas both in developed anddeveloping countries [WHO, 2005]. The range of adverse health effects is broad, affecting both therespiratory and the cardiovascular system. Children, women, and older adults are the mostsusceptible to these adverse health effects in the general population [WHO, 2005; Peel et al.,2007; Miller et al.,2007; Tecer et al., 2008]. The risk increases with intensity of exposure. Littleinformation supports the presence of a threshold level for these effects. In fact, effects were foundat very low levels of particulate matter, e.g. 3 to 5 µg/m3. The adverse health effects of air pollutionare observed both in short-term exposures and for long-term exposures [WHO, 2005]. Theseproblems are exacerbated by indoor air pollution typically caused by the burning of solid fuels.11