To me it is overwhelmingly clear that the great majority of people qualified to make a judgement on climate change are convinced that the planet is warming and that it is largely the fault of humans. My evidence of this view is found in this post.
Why then do so many people deny the obvious? Naomi Oreskes explains the origins and tactics of the deniers in the video below. It is long but well worth viewing.
UPDATE: When I wrote this I thought that a climate change denier might find it and make a comment. I was surprised that this attracted a different type of denier - a tobacco denier! I didn't know that such people existed.