Ozone and Mediterranean ecology: Plants, people, problems

摘要

Ozone (O_3) is both a toxic pollutant and a powerful greenhouse gas (Bytnerowicz et al., 2007). Ground-level background O_3 concentrations have doubled since pre-industrial times, and are rising at an annual rate of 0.5-2% over the mid latitudes of the Northern Hemisphere (Vingarzan, 2004). Since 1990, emissions of precursors in the European Union have declined by about 36%, because of the introduction of catalytic converters in cars and new laws to reduce air pollution (EEA, 2007). This reduction resulted in a decline of O_3 peaks, while annual mean concentrations are still increasing (Coyle et al., 2003; EEA, 2007). This may be explained by the fact that the formation of O_3 depends on complex chemical processes.