Global warming: the final verdict
Global warming is destined to have a far more destructive and earlier impact than previously estimated, the most authoritative report yet produced on climate change will warn next week.
A draft copy of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, obtained by The Observer, shows the frequency of devastating storms - like the ones that battered Britain last week - will increase dramatically. Sea levels will rise over the century by around half a metre; snow will disappear from all but the highest mountains; deserts will spread; oceans become acidic, leading to the destruction of coral reefs and atolls; and deadly heatwaves will become more prevalent.
The impact will be catastrophic, forcing hundreds of millions of people to flee their devastated homelands, particularly in tropical, low-lying areas, while creating waves of immigrants whose movements will strain the economies of even the most affluent countries.
'The really chilling thing about the IPCC report is that it is the work of several thousand climate experts who have widely differing views about how greenhouse gases will have their effect. Some think they will have a major impact, others a lesser role. Each paragraph of this report was therefore argued over and scrutinised intensely. Only points that were considered indisputable survived this process. This is a very conservative document - that's what makes it so scary,' said one senior UK climate expert.
Past assessments by the IPCC have suggested such scenarios are 'likely' to occur this century. Its latest report, based on sophisticated computer models and more detailed observations of snow cover loss, sea level rises and the spread of deserts, is far more robust and confident. Now the panel writes of changes as 'extremely likely' and 'almost certain'.
Now we need someone to write a comprehensive report outlining the economics costs of dealing with climate change - hasn't this just been done?