The August 13th edition of Newsweek has an eye-catching cover with a picture of the sun and the headline "Global Warming is a Hoax*". The asterisk goes on to say "Or so claim well-funded naysayers who still reject the overwhelming evidence of climate change. Inside the denial machine". This excellent article by Sharon Begley (with help from 4 others) gives a history of the denial efforts which started as a response to Jim Hanson's 1988 testimony to Congress and continue through today.
If you are new to this topic and think there's any doubt about global warming, please read this article and see how you've been manipulated. Even if this is all old news, its a good summary.
The article is mostly history but here's a quote about where things stand today:
To some extent, greenhouse denial is now running on automatic pilot. "Some members of Congress have completely internalized this," says Pew [Center for Climate Change]'s [Manik] Roy, and therefore need no coaching from the think tanks and contrarian scientists who for 20 years kept them stoked with arguments.
Fortunately, they can still be voted out of office.
Update: Joe over at Climate Progress thinks Newsweek wasn't hard enough. He also think the cover is a little to clever and I agree with that. A lot of people will just read the cover headline and not see the asterisk.
Update II: more on this article from me here and here.