Is climate change a trick?

It seems like a field day for those who believe climate change is a conspiracy. As mentioned in an earlier post (Global warming, nuclear power, and genetically modified crops), I believe climate change is attributable, at least in part, to human activity. The science in this matter is not absolute, and evidence confusing and sometimes ambiguous. There is no way to know definitively whether climate change is man-made, however, it seems sensible to act on that assumption. There is a more practical reason why the world needs to shift from carbon-based energy to renewables (and nuclear power). Oil is running out. As the oil reserves dwindle, the sticky stuff will become more expensive, and the renewables and nuclear will become relatively cheaper.