Climate change, impacts and vulnerability in Europe ... - MemoFin.fr

Climate impacts on socio-economic systems and health4.4.5 Air pollution by ozone and healthRelevanceOzone is a greenhouse gas, but ground level ozone isprimarily an air pollutant, which is of high concernin Europe (Confalonieri et al., 2007; Monks et al.,2009; EEA, 2011b). Concentrations of ground‐levelozone are determined by both precursor emissionsand meteorological conditions, which also influencethe transport of ozone and its precursors betweencontinents (UNECE, 2011). Ground-level ozone ishighly reactive and therefore harmful to vegetation,materials and human health. Short-term, high-levelexposure can cause breathing problems and lungdiseases, trigger asthma, and reduce lung function.The estimated effects of excessive exposure to ozone(exceeding the threshold of 70 μg/m 3 ) include about20 000 premature deaths, and 14 000 respiratoryhospital admissions every year in the EU-25, andup to 108 million person-days with minor activityrestrictions, respiratory medication use, coughor lower respiratory symptoms (WHO, 2008a).Evidence of chronic effects (asthma and lungdevelopment) of long-term exposure to high ozonelevels is still limited (WHO, 2008a; UNECE, 2011).There is a scarce evidence that high ozone levelscan further increase mortality during heat waves(Filleul et al., 2006).in Europe have largely stagnated. Meteorologicalvariability and climate change could play a rolein this discrepancy, including by increasingemissions of biogenic non‐methane volatile organiccompounds (NMVOCs) during wildfires, butincreasing intercontinental transport of ozone andits precursors in the Northern Hemisphere alsoneeds to be considered (EEA, 2010b; c). Formationof tropospheric ozone from increased concentrationsof CH 4may also contribute to the sustained ozonelevels in Europe (EEA, 2012).The relative contributions of local or regionalemission reduction measures, specificmeteorological conditions (such as heat waves),hemispheric transport of air pollution and emissionsfrom natural sources (such as wildfires), on overallozone concentrations is difficult to estimate.A statistical analysis of ozone and temperaturemeasurements in Europe for 1993–2004 shows thatin central-western Europe and the MediterraneanFigure 4.8O 3(μg/m 3 )Annual mean ozoneconcentrations (1999–2009)by station type100Past trendsThere is no clear trend in the annual meanconcentration of ozone recorded at differenttypes of stations (urban vs. rural) over the period1999–2009, although there is a slight decreasingtendency since 2006 in rural stations, at variousgeographical levels, both low-level and high‐level(Figure 4.8). Meanwhile, a slight tendencytowards increased annual mean concentrationsis detected close to traffic. Ozone precursoremissions in Europe have been cut substantiallyrecently whereas average ozone concentrations75502501998 2000 2002 2004 2006 2008 2010Urban Traffic Rural — low Rural — highSource: EEA, 2011b.Key messages: 4.4.5 Air pollution by ozone and health• Ozone is both an important air pollutant and a GHG. Excessive exposure to ground-level ozone isestimated to cause about 20 000 premature deaths per year in Europe.• Attribution of observed ozone exceedances, or changes therein, to individual causes, such as climatechange, is difficult.• Future climate change is expected to increase ozone concentrations but this effect will most likely beoutweighed by reduction in ozone levels due to expected future emission reductions.192 Climate change, impacts and vulnerability in Europe 2012