increasing levels of atmospheric carbon dioxide are turning the oceans acidic, warns the Royal Society, Britain's leading scientific organisation. The growing acidity is very likely to harm coral reefs and other marine life by the end of the century, the society said in a report prepared by a panel of scientists.

The phenomenon will affect all organisms that have skeletons or shells made of calcium carbonate, says the panel's chairperson, John Raven of the University of Dundee in Scotland.

More than 25 billion tonnes of carbon dioxide are released annually from the burning of fossil fuels (by cars and power plants). Almost a third of the carbon dioxide emitted is absorbed by the oceans, where the gas produces the harmful carbonic acid. The increased acidity could also reduce populations of plankton with calcium carbonate shells, disrupting the food chain and hurting some fisheries, the scientists said.

However, Sherwood B Idso of the us -based Center for the Study of Carbon Dioxide and Global Change