This skeptic presentation is pretty good, all science based:
I'm still keeping an open mind, here's where I am so far:
1) IPCC appears to be a quasi science / political
organization. Both sides agree on the this -- the AGW catastrophe side complains that because of its politics the IPCC is too conservative since they have to run everything past China and a host of other nations to reach what is really a political consensus. The skeptic side thinks the IPCC is biased towards the other direction. So both groups raise questions about the IPCC's credibility.
2) Everything, this whole darn thing, absolutely hinges on the "runaway warming" portion of the debate. Until I have a deeper understanding on that side, I can't possibly make up my mind in good faith.
3) Arctic ice cap loss is concerning, even if the Antarctic ice is growing. I'll have to look more into that.
4) The bogus hockeystick graphs still bother me, the way they just erased the little ice age and medieval warming period. In the video I linked, the guy talks a bit about computer models and how they can be made to predict the past just by adjusting the model -- that's not proof it can predict the future though, all you've done is made a model that can get the right answer for the past.
5) In the video linked above he talks about proxy paleotemp measurements. I've read about this in some other places, and I have a problem with some of the proxies. Tree rings for example -- tree growth varies over time for lots of reasons. More CO2 in the air can speed growth so how do we know the tree rings aren't really measuring CO2 concentration rather than temperature?
On a common sense level, I feel much more comfortable with ice core data. With that they're testing captured air samples from the past. What I wonder is, why use all the proxies why not just stick to Greenland and Antarctic ice cores? All these other proxies add a lot of room for error.
6) It sounds like on the international politicking side, developing countries come right out and say they'll try to do something with the caveat "as long as it doesn't hurt the economy." That remains a big problem with mitigation proposals, a first world only solution is not a global solution there's no getting around that.
7) To refresh my knowledge of the political side, I actually checked the GOP website. They don't even have a climate or environmental section.
They have a "energy" section under issues where they advocate more of everything: coal, nuclear, wind, oil. This is the only climate specific thing I could find:
We oppose so-called cap and trade legislation that would impose a national energy tax on families and small business that would kill jobs and raise utility prices.
EDIT: Other lingering doubts.. for more than a century we've been coming out of the little ice age, and we're still coming out of the little ice age so it makes sense that the planet is warming.
Also.. what is the "normal" climate anyway? The only way to pick normal is to put your finger on a graph, pick a date and decide to call that "normal." It may be "optimal" but there is no "normal." Of course, you guys say that it's human activity that will set off a runaway warming chain reaction and that's fair and I'm not sure on that. But I think most folks don't quite realize there is no "normal" climate either way, our species has already been up and down ice ages and warming periods about 4 or 5 times now.