Emissions of Sulphur Dioxide and Nitrogen Oxides from Large Combustion Plants11: 1996-2012
Sulphur dioxide (SO2) and oxides of nitrogen (NOx) affect human health through respiratory damage, and ecosystem health through acidification. SO2 and NOx are released into the atmosphere through the combustion of fossil fuels. In 2010, large combustion plants (LCPs) accounted for 81% of the SO2 emissions and 36% of NOx emissions in Scotland.4 In 2012 there were 54 LCPs in Scotland, down from 57 in 2011.
The Large Combustion Plants Directive (LCPD, since revised by 2001/80/EC) called for a 60% reduction in LCP SO2 emissions by 2003 and a 30% reduction in LCP NOx emissions by 1998, from a 1980 baseline. By 2002, total UK emissions of SO2 were 79% below 1980 levels, and 95% below 1980 levels in 2011. In 1998, total UK emissions of NOx were 60% below 1980 levels, and 74% below 1980 levels in 2011.12 The Large Combustion Plants Directive has now been superseded by the Industrial Emissions Directive 2010/75/EU, which was transposed into Scottish law by the Pollution Prevention and Control (Scotland) Regulations 2012.
In Scotland, SO2 emissions from the electricity supply industry fell between 1996 and 1999, but there were rises in 2000, 2006, 2009 and 2010. These rises were due to the cold weather and increased use of coal-fired power stations, necessary to offset the reduced capacity of the nuclear sector because of refurbishment work at certain plants. This was followed by decreases in 2007, 2008 and in 2011. In 2012, SO2 emissions increased by less than 1%, following a 28% decrease in 2011.
Despite increased production of electricity, emissions of NOx emissions decreased by 41% between 2006 and 2009, as new abatement technology helped to reduce the emissions of NOx. This was followed by a small increase of 5% in 2010, before a 22% reduction between 2010 and 2011, in part due to a reduction in Cockenzie's emissions. 2011 emissions of NOx were the lowest on record, with 2012 seeing an increase of 9%.
Source: Scottish Environment Protection Agency / Metadata