UN predicts more rainfall and heatwaves

Heatwaves will be longer, hotter and occur more often, and rainfall will be heavier during the 21st century because of global warming, a new UN report on climatic "extreme events" said yesterday.

Tidal surges are also likely to be made worse by rising sea levels, said the study by the Intergovernmental Panel on Climate Change (IPCC), and there may be an increase in danger in high mountains from phenomena such as landslides and the bursts of glacial lakes.

However, the long-awaited report was much more qualified in its assessment of the increased risks from hurricanes, droughts and floods. There has been frequent speculation that all three would increase in frequency and intensity with climate change, but the IPCC indicated yesterday that there was not enough evidence to draw firm conclusions.

Wind speeds in hurricanes and tropical cyclones were likely to increase, the panel said, but this might not occur everywhere, and the frequency of such storms was likely to stay the same or even decrease. There was only "low confidence" in the detection of any long-term trend.