Another thing I'd like to add to your global warming points which could apply to both liberals and conservatives, and other topics as well, is that it is a valid position to say "I don't know" or "I'm not sure". I think too many people hold their liberalism or conservatism as a self identity and they have to believe x,y, and z because they are a liberal or a,b, and c, because they are a conservative. Sure you find the rare liberal who supports gun rights or the rare conservative who supports abortion rights, but for the most part people tend to tow the line that they are supposed to on every issue. I have a number of issues that are hot button for me and I am very sure my opinions on, but there are some that I go back and forth on and that I will admit that I am not sure. Some of these are late term abortion, global warming, the death penalty. I've been on both sides of all of those and still haven't fully convinced myself one way or the other. At the moment I lean towards absolute abortion rights right up until the moment of birth; that anthropogenic global warming is probably happening, but that there is nothing governments can or should do about it at this time; and that the state probably shouldn't have the legal power to kill people in cold blood. But I am not truly happy with my position on any of those. Just because you lean one way or the other politically doesn't mean you have to fit yourself into the liberal or conservative box on every issue.
Also the practice I see often of what I call "labeling and dismissing", mostly by those on the left, but others do it too, isn't productive. People look for a key word or phrase in their opponent's argument then decide that they can give a label to the person himself (such as racist, sexist, fascist, socialist, capitalist, white male, homophobic, nazi, etc), then once said label is applied they can ignore all nuance or facts in the persons argument and just dismiss that person and everything that person says wholesale. I'm not saying that you should spend a lot of time talking to self avowed nazis, but the vast majority of the time, the labels people apply to others with the purpose of dismissing them and not having to think about anything they have to say are not completely justified. I think it is a defensive measure usually applied when something someone says starts to make a person uncomfortable with their own cognitive dissonance, but it is something that we can try to notice when we do it.