I recently saw the documentary on Channel 4 that promotes the view that human’s contribution to global warming is negligble compared to the effects of the Sun and cosmic rays. The documentary was well produced and quite convincing, and prompted much discussion in the media. It was certainly a topic in several conversations I had around the time. It did sound convincing that the Sun was the major factor controlling the world’s temperature, and that humans could do little to control global warming. But part of me remained unconvinced, and baulked at the idea that George W. Bush could be right in his opposition to the Kyoto Protocol
Now, New Scientist magazine has published a special issue about Climate Change, and it addresses many of the myths surrounding global warming. The key points are available in a series of articles on the New Scientist web site. They present a balanced view of the arguments, and I think they successfully challenge the points raised in the documentary. What I took away from it is that while the Sun does indeed act as the main source of heat for the planet, human-generated CO2 is the best candidate for the recent trend of increasing temperatures. It is also clear that there is a large degree of uncertainty around the role of clouds in the global climate. However despite the uncertainty the majority of scientists working in this field are convinced that human-caused global warming is real, and we need to act sooner rather than later.