Climate change deniers an interesting study in themselves

Climate change is now accepted "science", but some notable sceptics still argue to defend their position - even in public! Several who were named were Don Aitken (http://donaitkin.com/), Geoffrey Blainey and Ian Plimer
How do such people come to their views, and why does this phenomena continue?
This was discussed on Late Nite Live by Phillip Adams and  Tom Griffiths, a Professor of History and Director of the Centre for Environmental History at the Australian National University, Canberra, on July 31. Tom's views are summarised in an essay -

http://griffithreview.com/edition-41-now-we-are-ten/weather-and-mind-games

We would do well to attempt to understand how people develop their opinions.