Honest answer from a denier. I've found myself jumping on the climate change skeptic bandwagon, and there are a bunch of different reasons for that, none of them having to do with the actual hard data or the models, or any of the details of the science, except for some specific tidbits that enable my skepticism. (For example, most of the models I've looked at predict milder summers and warmer winters in my particular area, and flooding in areas, not nearby, where people I don't like currently habitate)
People (myself included) don't want to hear it for the same reason that people get huffy when you mention that whole food veganism is bar none the best diet to avoid cancer and heart disease. They'll just point out the few that stil get cancer, and still get heart disease. Or smokers when you point out the cancer risks...plenty of smokers don't have a problem and live to healthy old age.
But, you CAN find a positive. If you point out that the hottie jogging down the street is always a non-smoker, and always either a vegan or a Paleo with higher than average vegetable intake, no one can really argue with that one, and if you ask one of them they'll confirm that observation every time.
When the climate change topic comes up, my brain automatically translates that the punitive corrective measures bandied about over the years...Carbon Tax, Environmental Regulation, and all the other proposed measures that wind up trading modest pollution levels for wideband economic austerity.
I know it is frustrating when you're trying to get people to stop polluting and people want to turn a blind eye to it and keep going about their business. Yet, basing your argument on science models that can predict the climate 10 years into the future yet somehow can't predict the climate tomorrow...yeah, if there are ANY holes whatsoever in your argument when you're preaching austerity, everyone is going to focus on the holes in the argument, no matter how small or short-sighted.
I think you'll find less resistance from me or anybody else if you focus on things that elicit a positive image...like pushing increased research funds for cleaner burning engines, real fuel production alternatives like algae. Things that benefit everyone, AND reduce environmental impact. But by default I'm going to automatically assume your motive is to argue for higher taxes and economic austerity, and of course I'll get turned off pretty quick.