Matt Maroon in Global Warming & Epistemology articulates far better than I can the reasons for believing that global warming is happening, is caused by mankind, and needs to stop as soon as possible.

Nobody can be right about everything, and the nature of climate change is that the ultimate decisions have to rest with citizens, the politicians they elect, and entrepreneurs, most of whom can’t be expected to know everything about everything, or even everything about global warming. The best they can do is take the most informed opinions around and act on them.

Well worth reading.