Climate Change Denying

The deposits of fossil fuels that we have been cheerfully consuming over the last 100 years or so, and at an ever-increasing rate,  were gradually laid down over many hundreds of thousands of years. Although aspects of  the present theories and predictions of climate change may still be open to be dispute or questioning, what climate change deniers, like Simon Heffer of the Telegraph, first need to tell us is; why should releasing this carbon in such a small fraction of the time in which it was laid down not produce some observable effects on the climate? If they can't, the sensible thing for the time being is to assume the worst and do what we can to get off this carbon jaunt.