Air Quality & Climate Change

Professor Martin Williams
Science Policy Group, King's College London

The UK is unique in Europe and the rest of the world in having incorporated into primary legislation an ambitious target for the reduction of greenhouse gases in the Climate Change Act of 2008, namely a reduction of 'carbon dioxide (CO2) equivalents' of 80% by 2050 compared with a 1990 base.  

An ambitious target such as that set by the UK will clearly require large reductions in emissions which in turn will potentially require major changes in the energy supply and the transport systems in the UK. The achievement of this target could, if the right choices were made, also result in large reductions in air pollution and an associated improvement in public health impacts. 

These impacts have been estimated to be associated with 29,000 deaths in 2008, and to amount to a reduction in life expectancy across whole populations ranging from 3-4 months in Scotland and Northern Ireland, and 6-7 months in England and Wales. The damage cost to society has been estimated as £20 billion per annum. However, other policy choices to achieve the 2050 target could lead to much smaller reductions in air pollution and give much less of an improvement in public health.

There are therefore important choices to be made. Of choices which lead to reductions in CO2 equivalents, some may not lead to improvements in air quality. An example is the use of biomass, or wood, in place of coal or oil or other fossil fuels whose carbon was laid down in prehistoric times. 

The continued use of diesel cars instead of petrol vehicles is another example. Diesels can emit less CO2, but emit considerably more particles and other harmful pollutants such as the oxides of nitrogen (NOx). Also, small scale (community level) heating and energy systems can lead to local increases in air pollution. While they can provide better fuel efficiency, they bring pollution back in to cities from the remote rural power stations and hence can cause additional adverse effects on health.

The project intends to assess the impact of different choices or scenarios for achieving the 2050 target and their respective impacts on air quality and public health and to suggest optimal ways of achieving the 2050 target.