Scientists are predicting that coral reefs could start to dissolve within 30 years as rising carbon dioxide levels make the seas more acidic.

Scientists at a climate-change conference in Exeter heard yesterday that the sea is soaking up about 48 per cent of man-made CO2 emissions. The process delays global warming, but ocean scientists believe it is making the water slightly more acidic.

Israeli scientists forecast that as CO2 emissions continue to grow, the acidity will get worse and many species of coral organisms will be unable to build their shells. Their studies of corals in the Red Sea suggest that the tipping point will be reached between 30 and 70 years from now. Professor Jonathan Erez's team, from the Hebrew University of Jerusalem, has been taking chemical samples of seawater on the reef in the Red Sea at Eilat. The team says it has found that, at times when natural causes make the water more acidic, the corals grow more slowly. They predict that CO2 emissions will greatly exaggerate the effect.

Professor Erez told BBC2's Newsnight: "This ecosystem, which is the most productive and diverse in the ocean, is going to disappear as an ecosystem. The individual components may survive here and there but, as an ecosystem, our grandchildren will not see coral reefs any more."