Further cuts in emissions of air pollutants needed

The European Environment Agency (EEA) recently released its fourth state of the environment report (SOER 2010), providing a comprehensive assessment of how and why Europe’s environment is changing.

As part of the SOER 2010, thirteen Europe-wide thematic assessments of key environmental issues have been done, one of which deals with air pollution. In this, it is noted that the most problematic pollutants in terms of health damage are fine particles (PM), ground-level ozone (O₃) and nitrogen dioxide (NO₂), and that many EU member states do not comply with legally binding air quality limits. Effects of these pollutants can range from minor respiratory irritation to cardiovascular diseases and premature death. An estimated 5 million years of lost life per year are due to fine particles (PM_2.5) alone in the 32 countries covered by the EEA.

The EU has not achieved its interim environmental objective that was set to protect sensitive ecosystems from acidification. However, in the EEA-32, the ecosystem area affected by excess acidification due to air pollutant depositions was significantly reduced between 1990 and 2010. This was mainly a result of past sulphur dioxide (SO₂) abatement measures.

Nitrogen compounds, emitted as nitrogen oxides (NOx) and ammonia (NH₃), are now the principal acidifying components of air pollution. In addition to its acidifying effects, nitrogen deposition also contributes to nutrient oversupply (eutrophication) in terrestrial and marine ecosystems, leading to changes in biodiversity. The area of sensitive ecosystems affected by excessive atmospheric nitrogen diminished only slightly between 1990 and 2010.

Exposure of crops and other vegetation to elevated levels of ground-level ozone will continue to exceed long-term EU objectives.

In terms of controlling emissions, only 14 countries expect to comply with all four pollutant-specific emission ceilings set under EU and international legislation for 2010. Emission ceilings for NOx are the most challenging – 12 countries expect to exceed their ceilings, some by as much as 50 per cent.

Despite significant reductions since 1990, the energy sector is still responsible for nearly three-quarters of the SO₂ emissions and one-fifth of the NOx output. Another important source of pollution is road transport – heavy-duty vehicles are an important emitter of NOx, while passenger cars are among the top sources of carbon monoxide (CO), NOx, PM_2.5 and non-methane volatile organic compounds (NMVOCs). Energy use by households – the burning of fuels such as wood and coal for heating – is an important source of PM_2.5. Agriculture is responsible for 94 per cent of the ammonia emissions.

Under a current policy scenario, the EEA-32 and western Balkan emissions of the main air pollutants are projected to decline by 2020. The largest proportional decreases are projected for emissions of NOx and SO₂. Emissions of PM_2.5 and NH₃ are however projected to be similar or even slightly higher than in 2008, although substantial reductions are technically possible.

EEA concludes that successfully addressing air pollution requires further international cooperation. There is growing recognition of the importance of the long-range movement of pollution between continents and of the links between air pollution and climate change. Factoring air quality into decisions about reaching climate change targets, and vice versa, can ensure that climate and air pollution policies deliver greater benefits to society.

Christer Ågren

Source: Air pollution – SOER 2010 thematic assessment, 30 November 2010.