Do I accept the science that says the Earth's climate is warming? Yes. Do I accept the countless studies that show that its anthropogenic? Absolutely. Do I think Global Climate Change is a winning argument in getting Americans to reduce their fossil fuel use? Not one fucking bit.
The problem is that, unless you are a scientist or a nerd, global climate change doesn't work on a scale that most people can understand. It's the same problem you run into when trying to explain evolution or the problems with most science fiction. The human mind just isn't conditioned to perceive the world on those kinds of scales. This is why so many people look at things such as the 3 blizzards that hit the DC area last winter and say 'See, the planet can't be warming! There were blizzards in DC!' Now you can try and educate people, and you may even succeed with some of them, but most people just can't wrap their minds around those kinds of scales. You just start running into what I like to call the Murder Paradox. 1 murder is a horrible crime. 2 murders is depravity. 1000000 murders is a statistic. The only way to get people past this is to shrink the scale of what you are talking about to a more human scale. Go through any history class where they talk about how many Jews were killed in Nazi Germany or how many Cherokee died on the trail of tears and the numbers just don't trigger the same response as the first hand stories of the horror do; and look at how few people at the time could accept the reports they heard out of Europe till the first videos of concentration camps brought it home. Similarly, when you talk about climate change and how it will affect things 20, 50, 100 years or more down the road it just is beyond what the human mind can easily envision.
Now add to this the fact that science is an area that values "flip flopping" and encourages its practitioners to reevaluate their beliefs and you are running into a disaster waiting to happen. Right wing loons just go and point out that scientist changes, that it isn't set in stone and use that to discredit the argument.
So what's the solution? Well I would suggest that instead of using global warming as an argument we instead focus on stuff that's harder to deny, such as the limited supply of fossil fuels. It becomes harder to refute that and it works to achieve the same goal of reducing carbon emissions.