Air pollutant emissions and acid rain on the decrease in the UK

According to this year’s National Atmospheric Emissions Inventory (NAEI), other air pollutants that have decreased in the UK include mercury, which is down 71%, PM10 particles, down 39%, methane, down 28%, carbon dioxide, down 9%, and ammonia, down 5%. Overall, emissions of greenhouse gases fell by 14%, although one gas, sulphur hexafluoride (SF6) – which accounts for only 0.2%, increased, mainly due to industrial applications, said the report.

The air pollution emissions reductions are due to a combination of domestic and international regulation, technological and process improvements in industry that have been stimulated by the government, as well as changes in economic activity, and changes to the taxation system. In the case of carbon dioxide, emission reductions have been affected by changes to the energy supply market.

More specific examples of reduction methods that have contributed to the new figures include the introduction of catalytic converters on cars, improved waste gas abatement, the use of cleaner fuels, cessation or reduction of activities such as coal mining, general process efficiency in industry, and pollution control measures in industry. However, the report notes that although catalytic converters have reduced emissions of pollutants such as carbon monoxide, benzene, and 1,3 butadiene, they also increase emissions of nitrous oxide. Nevertheless, industrial pollution control measures have reduced overall emissions of the gas.

“We are committed to publishing information on the environment and these latest estimates are very good news,” said Environment Minister Michael Meacher. “They reflect improvements achieved under the UK’s Air Quality Strategy, action to tackle greenhouse gas emissions, and effective collaboration with organisations such as the European Union and the United Nations, in developing and implementing international policies to reduce emissions of harmful pollutants.”

“But even though these figures are encouraging, we must not be complacent,” said Meacher. “There are still significant problems where we need to do more. For example, to further reduce greenhouse gases and harmful pollutants such as ammonia and particulate matter.”

A second report, by the National Expert Group on Transboundary Air Pollution (NEGTAP), revealed that damaged freshwater lakes and streams are showing signs of recovery following a 50% reduction in acid rain in the UK, resulting from curbs on sulphur dioxide over the last 12 years.

The report also reveals changes in plant diversity across the UK, in which eutrophication caused by emissions of oxides of nitrogen and ammonia, may play a significant role. And, although ozone has declined by 30% since 1986, levels of the pollutant are set to rise in the future, largely as a result of increasing air pollution in the rest of the world, with implications for crops, forest production, and natural vegetation.

“This report contains both good and bad news,” said NEGTAP Chairman Professor David Fowler. “We are beginning to see improvements from the significant reduction in emissions of air pollutants over the last decade. We now have clear evidence that UK ecosystems which were damaged by acid rain are beginning to recover. This is encouraging, but full recovery will take decades. But there are still problems to be solved. Specifically, ground-level ozone and terrestrial eutrophication will continue to pose problems in the future.”