The correlation between warming, as measured by thousands of weather stations on land, at sea and on moving and fixed buoys, and that increase in concentration of atmospheric carbon dioxide which can only have been brought about by human activity is just about perfect. Of course, you don't have to trust the science. Pete doesn't trust the science and big oil doesn't trust the science. Yanks with gas-guzzling six-pots running on super-cheap petrol don't trust the science. But the science applies very careful corrections for instrumental bias, for irregular distribution of recording stations, for irregularities of instrumental exposure and for a whole host of other potential sources of error. Despite that, the conclusions are scary. The planet is warming because of what we do. We deny it at our peril.