What is happening to the climate? Climate Change 2007 - The Physical Science Basis is the most comprehensive and up-to-date scientific assessment of past, present and future climate change. This report has been produced by some 600 authors from 40 countries, over 620 experts and a large number of government reviewers. Providing insights into the effects of human activity on the atmosphere, and containing an evaluation of observed climatic changes using the latest measurement techniques, the report also includes a detailed review of climate change observations and modelling for every continent as well as the first probabilistic evaluation of climate model simulations. Simply put, this latest summary from the IPCC forms the standard scientific reference for all those concerned with climate change and its consequences, including students and researchers in environmental science, meteorology, climatology, biology, ecology and atmospheric chemistry, and policy makers in governments and industry worldwide.