The curious thing about the UN IPCC is that the Report for Policy Makers is written by politicians rather than scientists, and it is often reported that the report by scientists does not back up the politicians report. Here is a comment by a member of the UN IPCC science body that I completely agree with. Note his comments on the predictive value of untested computer models. Based on my experience, the UN IPCC climate models are not only unvalidated, they cannot be validated. The Earth's climate system is a chaotic non-linear system with a vast number of variables, many of which are unknown and some of which are unknowable. Note the comments about cooling. No one wants the Earth to be colder. In the history of mankind warmer has been better than colder. Living in an ice age would be no fun at all.