Impact of climate and emission change on ozone induced mortality in Europe with combining effect of heat

Abstract

Introduction Ozone is a highly oxidative pollutant, associated with increasing mortality. All else (e.g. ozone precursors) being equal, summertime ground-level ozone will increase as temperatures increase with climate change. As a part of the ACCEPTED project we will use CO2 emission scenarios, global and regional climate and chemistry-transport models, epidemiological data and population projections to assess ozone- and heat-related health impacts under a changing climate. Methods European ozone concentrations are modelled at a grid size of 50x50 km using MATCH. Climate projections from the regional climate model, RCA4 are used. For the surface ozone and temperatures the global climate model EC-EARTH, was used as input of the regional climate model, forced by the greenhouse gas emission scenario RCP4.5. Two periods were compared: the current climate as 1991-2000 and future climate as 2046–2055. The impacts on long-term mortality due to ozone exposure from April-September and heat related premature deaths in Europe are calculated. Results When only taking into account the impact of changing climate on summertime surface ozone, up to 16% increase to the ozone-associated mortality is expected in Central- and Southern-Europe. However, projected decrease in ozone precursor emissions will cause much larger decrease in surface ozone (45% as EU average). Furthermore, due to aging Europe and increasing susceptible populations, the ozone related mortality might yet increase by 5.8%. During summer months, there is also combining effect of heat, especially during hottest periods and in densely populated urban areas. While the effects of heat are at the moment 20-25% larger compared to ozone, due to increasing temperatures and decreasing ozone precursor emission, the difference will be three times in 2050. Conclusions Climate and emission changes will substantially affect ozone and temperature related mortality and the ratio between them in the middle of this century in Europe.