Acid rain pollution halved in 15 years

Acid rain, one of the greatest pollution scourges of the last decade, is being rapidly reduced across Britain and Europe, a new official report reveals. It concludes that the acidity of rainfall in Britain has been cut in half over the past 15 years and that acidified lakes in Scandinavia are beginning to recover in what promises to be one of the most remarkable environmental success stories on record.

Acid rain, one of the greatest pollution scourges of the last decade, is being rapidly reduced across Britain and Europe, a new official report reveals. It concludes that the acidity of rainfall in Britain has been cut in half over the past 15 years and that acidified lakes in Scandinavia are beginning to recover in what promises to be one of the most remarkable environmental success stories on record.

The report, by the National Expert Group on Transboundary Air Pollution, also shows that Britain – once both one of Europe's worst polluters and the most reluctant to clean up – has been in the lead in cutting its emissions.

Acid rain comes mainly from sulphur and nitrogen released by the burning of fossil fuels in power stations, industrial boilers and vehicle engines. The pollutants combine with water vapour, sunlight and oxygen to produce a dilute soup of sulphuric and nitric acid which then falls as rain, often hundreds of miles from where the pollutants were originally emitted.

Nearly a quarter of Sweden's 90,000 lakes have been affected, 4,000 of them so badly that no fish could survive. Thousands more lakes in the eastern USA were "killed''. Researchers in Germany concluded that acid rain was to blame for an alarming sickness of the country's forests, giving rise to its Green party.

Britain came in for particular censure. Its pollution blew over the North Sea to become one of the main causes of the damage in Scandinavia. Yet for years successive governments and the electricity generating industry refused to accept that the problem existed. In the early Eighties Margaret Thatcher's government repeatedly refused to join an international agreement to cut emissions by 30 per cent, yet the report – by a group of British, Dutch and Scandinavian scientists, to the Department for Environment, Food and Rural Affairs – says that Britain has now cut emissions of sulphur by 80 per cent and those of nitrogen by 40 per cent since their peaks and that these are still falling.

The cut in sulphur was largely brought about by switching electricity generation from oil and coal to less polluting gas and nuclear power, and by saving energy. Nitrogen emissions went on rising for much longer because of the growth in traffic – the main source of the pollution – but then fell, partly because of the introduction of catalytic converters on car exhausts.

Much the same has happened across Europe, where emissions of sulphur have been cut by 41 per cent and those of nitrogen by 21 per cent since 1990. The Continent has consistently beaten the clean-up targets it set itself.

But the report concludes that acid rain has been cut far less in western Britain – the most affected region – than in other parts of the country, because it is receiving pollution on the winds from the US and ships in the Atlantic.