Acid rain: An environmental crisis that disappeared off the radar

You can tell an environmental problem has gone off the radar screen when Friends of the Earth don't have anybody tracking it, and that's the case with acid rain. There is currently no acid rain campaigner at FoE in London (although they will cheerfully point you in the direction of an expert).

These days, the focus of green campaigners has switched almost entirely, away from air pollution to climate change. Yet a generation ago, acid rain was one of the highest-profile green issues, of concern to all the main campaigning environmental groups and to the general public, who were presented with apocalyptic visions of forests dying and lifeless rivers.

It was also the subject of angry argument between nations – not least between the Scandinavian countries, and Britain. In the mid 1980s, when the row was at its height, Norway and Sweden took very strong objection to the fact the acid rain they were suffering from, which was causing serious problems for their forests and lakes, was largely British in origin.

Much of Britain's electricity was then generated by big coal-burning power stations situated in northern England on the eastern side of the Pennines, such as Drax in Yorkshire. These plants burned enormous amounts of coal with a very high sulphur content, and the resultant sulphur dioxide emissions from the power station chimneys were blown by the prevailing westerly winds across the North Sea, transformed into sulphuric acid and deposited on the Scandinavian land mass.

For Britain it was unfortunately "out of sight, out of mind", and the Norwegians and Swedes were furious that the then Prime Minister, Margaret Thatcher, with Britain's Central Electricity Generating Board run by a Thatcher favourite, Walter Marshall, were long disinclined to take responsibility.

Eventually, however, Britain accepted it had to do something and at considerable expense, flue gas desulphurisation equipment, or sulphur "scrubbers", were fitted to all major power station chimneys. Since then atmospheric sulphur emissions have tumbled in Britain by about 85 per cent. But nitrogen is the new concern now.