S. Fred Singer is the KING of climate denialists. In this presentation, he discusses how denialists can defend their position. If you can’t stomach watching it, I’ll do you the favor and summarize the denialist technique:

• Step one, call the other side names
• Step two, call the evidence presented names (e.g., “THE IPCC IS A JOKE!”)
• Step three, USE ALL CAPS AND/OR YELL
• Step four, take quotes out of context
• Step five, place technical scientific jargon in “quotes.” This serves to make fun of the term, which somehow shows the term is false. (e.g., “Climate alarmists point to so called, “climate computer models”“.). It’s easy to manipulate most people, since they are unfamiliar with these fancy terms.
• Step six, point to a graph and state that graphs can be made up. Dive into a conversation about how statistics can be manipulated. Do not provide evidence that the graph you are pointing to is actually true or false. 
• Step seven, create a diversion. This is best performed by claiming the science doesn’t show x thing. (e.g., “What this silly little graph doesn’t show is, blah blah.”). Again, always make fun and never, ever show evidence.
• Step eight, blend any of the above fallacies into one sentence and a presto! You are a denialist! 

For a list of other fallacious techniques used by denialists, have a look here.