Ancillary Air Quality Benefits

Submitted by Michael Rastall 29th November 2012 16:50


Key Messages

  • Mitigation policy has a beneficial effect in reducing greenhouse gas (GHG) emissions, because it introduces cleaner fuels and improves energy efficiency. These mitigation measures also reduce emissions of air pollutants such as oxides of nitrogen (NOx), sulphur dioxide (SO2) and fine particles (PM), and as a result, they improve air quality.
  • Despite large improvements in Europe in recent decades, current air quality (air pollution) levels are responsible for adverse health and environmental impacts, including a significant shortening of life expectancy. These impacts have large economic costs. The air quality improvements from mitigation policy will reduce these costs, and therefore lead to economic co-benefits.
  • These ancillary co-benefits are important when comparing the costs and benefits of mitigation. Whilst the full benefit of European GHG reductions may only be experienced by future generations and occur at the global level, the ancillary benefits of air quality improvements occur in the short-term and lead to direct (local) benefits in Europe.
  • The ClimateCost study has assessed the health, environmental and economic air quality benefits of mitigation policy. The analysis used the GAINS and ALPHA models to assess a mitigation policy scenario that is consistent with the EC’s 2 degrees target, and compared this to a baseline medium-high emissions scenario.
  • The estimated benefits of the 2 degrees stabilisation (mitigation) scenario, over and above the baseline scenario, are substantial.Under the mitigation scenario, there are large reductions in EU air pollutant emissions, with a 60% reduction in sulphur dioxide (SO2) and a 46% reduction in oxides of nitrogen (NOx) when compared to the baseline in 2050. There is also a 19% reduction in emissions of particulate matter (PM).
  • Under the mitigation scenario, there are large reductions in EU air pollutant emissions, with a 60% reduction in sulphur dioxide (SO2) and a 46% reduction in oxides of nitrogen (NOx) when compared to the baseline in 2050. There is also a 19% reduction in emissions of particulate matter (PM).
  • These emission reductions – and the associated improvement in air quality – lead to large health benefits. Under the mitigation scenario, average life expectancy in Europe (EU27) is extended by 1 month of life by 2050: equivalent to an annual benefit of 480,000 years of life.
  • In addition, the mitigation scenario reduces the number of ozone related deaths in the EU27 by 3400 fatalities a year by 2050, as well as reducing the annual number of cases of chronic bronchitis and hospital admissions by 27,000 and 20,000 respectively. It also leads to an estimated reduction of 127 million minor symptom days each year by 2050.
  • The economic benefits of these health improvements are estimated at €43 billion per year in 2050 in the EU27 (current prices, undiscounted), based on a value of life years lost approach for the change in mortality risk. Using an alternative valuation metric of the value of a statistical life, the benefits of the mitigation scenario increase to €94 billion per year by 2050.
  • When expressed against the CO2 reductions achieved, the air quality co-benefits of the mitigation scenario are around €24 for each tonne of CO2 reduced over the period investigated.
  • GHG mitigation policies also reduce the need to implement air quality pollution measures and equipment required by legislation. These avoided costs have also been considered in ClimateCost, using the GAINS model. Under the mitigation scenario, the regulatory air quality costs in the EU27 are reduced by €36 billion per year by 2050, mostly due to avoided costs of NOx and PM control in the transport sector.
  • The mitigation scenario also leads to important co-benefits for managed and unmanaged ecosystems, reducing acidification and eutrophication. Under the mitigation scenario, the area of forest in the EU27 that exceeds the critical loads for acid deposition is reduced by 42 thousand km2 by 2050, a 15% reduction on the baseline. The area of ecosystems in the EU27 that exceeds the critical load for nitrogen deposition and eutrophication is reduced by 144 thousand km2 by 2050.
  • The study has also considered the air quality benefits of global mitigation policy in other world regions using the GAINS model, which reveals even larger health benefits. Under the mitigation scenario, the average life expectancy gain is estimated at 19 months in China and nearly 30 months in India by 2050, compared to the baseline, and would also reduce ozone related mortality by more than 75 thousand cases per year across the two countries.
  • The magnitude of the co-benefits above demonstrates they are very relevant to the policy discussion on the costs and benefits of mitigation. It also emphasises the importance of exploiting synergies in the fields of climate and air pollution.

Citation

Holland, M., Amann, M., Heyes, C., Rafaj, P.,Schöpp, W. Hunt, A., and Watkiss, P. (2011). The Reduction in Air Quality Impacts and Associated Economic Benefits of Mitigation Policy. Summary of Results from the EC RTD ClimateCost Project. In Watkiss, P (Editor), 2011. The ClimateCost Project. Final Report. Volume 1: Europe