How reliable are predictions of future climate changes?

In February 2007, the United Nations Intergovernmental Panel on Climate Change (IPCC) stated that changes in the atmosphere, the oceans and glaciers and ice caps now show unequivocally that the world is warming due to human activities. The IPCC, made up of the world’s leading climate scientists and experts, found that scientists now have “very high confidence” – at least a 9 out of 10 chance of being correct – in their understanding of how human activities are causing the world to warm. This level of confidence is much greater than the IPCC indicated in their report in 2001.