Sorry Einstein, I'm not convinced. Temperatures in London 100 years ago were as warm as they are today before they fell and rose again, all in the last hundred years, which suggests temperatures can fluctuate naturally over reasonably short periods of time. It is also believed that the 13th century was significantly hotter in Britain than it is today (although temperature measurements were of course no where near as accurate). One large volcanic eruption such as might occur every couple of years somewhere on the Earth, throws up more pollution in a few hours than all the pollution created by humans in the history of our race. When Krakatoa erupted in the 19th century, it turned the sky red for weeks on the other side of the world, due to all the contaminents it had thrown up. No doubt pollution in cities is a genuine problem, causing increases in resiratory diseases, but the idea that modern human living makes any significant difference in the overall climate on Earth is doubtful, according to an increasing number of scientists and organisations who claim to be experts in the field. NASA for one publicly downplayed any human influence on global warming a few years ago. Although certainly no expert, I did study long and short term global climate change at degree level 3 years ago, including its likely causes. No doubt the issue is still open to interpretation, but I just wanted to put my case across. Sorry to have gone off subject, I'm sure we were talking about dolphins...