John Cook, of Skeptical Science fame, has created an online course through the University of Queensland and edX, on denialism and climate change. Easy to access and free to take, I found it simple to join from their facebook page, and if you don’t want to join you can still see the lectures from their Youtube channel.
Having gone through the materials so far I have to say Cook nails it. His graphic depicting the 5 tactics is very clear and easy to understand.
Also I think he has done a great job of making clear that the problem isn’t one of education, facts or knowledge. The problem is the way we think, and how our ideology skews what we are willing to believe, setting us up to fall for denialist arguments. That combined with the series of high-quality experts from Oreskes to Mann makes for a really excellent introduction to the problem from real experts in the field.