The initial results of the largest climate prediction experiment make worrying reading. Greenhouse gases could cause global temperatures to rise by up to 11 degrees Celsius by the middle of the century. Such a temperature increase is more than double the maximum warming so far considered by the Intergovernmental Panel on Climate Change (IPCC). The experiment, known as climateprediction.net 'shows that increased levels of greenhouse gases could have a much greater impact on climate than previously thought,' said the project's Chief Scientist, David Stainforth from Oxford University. The experiment was made possible by the involvement of more then 95,000 people from 150 countries via their computers. Schools, businesses and individuals from around the world have downloaded software incorporating the UK Met Office's climate model that runs when their computers are idle. The programme runs through a climate scenario over the course of a few days or weeks, and then automatically sends the results back to Oxford University and collaborating institutions around the world. Participants have already simulated over four million model years and donated over 8,000 years of computing time. This far exceeds the processing capacity of the world's largest supercomputers. The project scientists are urging more people to get involved, however. 'Having found that these extreme responses are a realistic possibility, we need people's support more than ever to pin down the risk of such strong warming and understand its regional impacts,' said Mr Stainforth.