Integrated Climate Policy Assessment

Evaluating the efficiency of environmental policies in Europe and in the world

Air pollution has been one of Europe's main political concerns since the late 1970s. European Union policy on air quality aims to develop and implement appropriate instruments to improve air quality. Whereas emissions of harmful pollutants like sulphur dioxide and lead have been successfully reduced in the past decades, other components like nitrogen oxides, volatile organic components (both being the precursors for the formation of ground level ozone) and particulate matter (PM) are still a matter of concern.

Ozone is known to cause damage to vegetation in general and crops in particular, and may constitute a significant threat to food security, especially in developing economies where the quality of the air is still deteriorating.
Particulate matter is known to be a threat to human health: the average life expectancy of people living in European urban environments is reduced by 18 months.

What is the actual impact of air pollution locally and on global scale? What can be expected from the implementation of emission ceilings and other measures that are gradually being implemented? How will policies aimed at reducing greenhouse gas emissions help to further improve the air quality? What is the optimal mix of measures to obtain the desired targets in terms of air quality and climate?

The global chemistry transport model TM5 is used to explore how emissions of air pollutants affect the air quality, and how this impacts on human health and vegetation. TM5 calculates the ozone concentration near the surface, and the amount of particulate matter (link to TM5 story). These calculations are being made for the present-day situation, as well as for projected emissions in a medium-term future, based on possible emission scenarios which are in turn linked to a set of environmental policies.

Example: the impact of present and future air quality on crop production losses from ozone.

Projected change in the relative yield loss by 2030 under implementation of current legislation for the globe and major world regions (India: no legislation assumed). Negative numbers indicate a lower loss. Error bars indicate the range obtained from various methods.

Change in relative yield loss by 2030, CLE