Climate change is associated with an increase in greenhouse gases (the quantity of carbon dioxide in the atmosphere). Their main sources are industrial activities and transportation, as well as massive deforestation, with consequences on air quality.

Air quality impacts both the environment, and the health of the population. According to World Health Organisation, over 95% of the European urban population is exposed to air pollution levels that exceed European standards. Among the main factors that impact air quality are gas emissions generated by urban traffic. Air pollution continues to affect vegetation and ecosystems (which face excessive nitrogen deposits, a major cause for the disappearance of species). Despite the existence of a series of national and European regulations on gas emissions reduction, in the medium and long term the impact of these norms is expected to be quite low (according to European Commission’s estimations for the European economic area in 2030). This subfield has two main indicators: GHG emissions, per sectors, and GHG emissions in ESD sectors (an acronym used to evaluate greenhouse gas emissions from nonindustrial and non-agricultural activities, such as air transport). The subfield has four secondary indicators: air pollutants, by source sector; annual mean of exposure to air pollution by particulate matter; mean near surface temperature deviation, as well as average annual precipitation, per region.