A new report on Britain's environment found that levels of sulphur in our atmosphere have dropped 90 per cent compared with their peak level in the 1950s.
Now a similar political drive is needed to tackle the problem of nitrogen emissions from cars, power stations and farms and prevent the pollution from killing off wild flowers, experts said.
Having too much nitrogen in the atmosphere over-fertilises the Earth and allows grasses and weeds such as nettles to flourish, causing the disappearance of wild flowering plants.
The warning came in a new report led by the Centre for Ecology and Hydrology, which analysed how the chemical climate of the UK has changed in recent decades.In the 1970s sulphur pollution released in Britain caused acid rain which damaged limestone buildings and made freshwater lakes in Britain and Scandinavia more acidic, killing fish.During the 1980s Mrs Thatcher's government committed to tackling the problem, resulting in a major improvement in the cleanliness of air and water, but similar efforts are needed to tackle the problems of ground level ozone pollution and nitrogen, the report said.
Prof David Fowler, who led the study, said: "Margaret Thatcher decided there was a problem and we needed to fix it...you only have to see the air quality across the UK, how clean the air is, to see we've made big progress."No-one has decided to do the same for nitrogen. There is no great policy we have to fix the nitrogen problem, and that is why it is generally becoming a bigger issue."