Reality based community, do you think that a lot of global warming deniers don't even really understand what?

I think most reject it (and also accept it) on purely political grounds, supported by lots of cutesy faux science, like

How come the Earth has gone through climate cycles before, did the cavemen drive SUVs?

If we are causing the warming on Earth, how come it's also warming on planets Y and Z?

When we can't predict the weather a week in advance, how can we predict the climate in 50 years?

I'm afraid many people can't distinguish between real science and faux science, so they just go with what their political persuasion tells them.

Perhaps you don't actually understand the theory. Let me explain. There are two parts to the theory. One is that CO2 is a greenhouse gas and increase the atmospheric concentration should increase the amount of heat retained by the atmosphere thus causing global average temperatures to rise in direct proportion.

The second is the climate sensitivity. That is, if CO2 rises and temperature rises, what other processes are brought into play? For example, do the oceans retain some of the heat? Is there more evaporation which also absorbs heat? Do more clouds form due to increased evaporation thus causing a cooling effect by blocking UV radiation? These processes are known as feed-backs and they are not entirely understood. The IPCC currently assumes that climate sensitivity is high meaning that CO2 increases will result in temperature increases. Other climate scientists claim climate sensitivity is low or in other words, the increased CO2 is counteracted by other negative feed-backs which minimize the warming effect.

So if your understanding of the theory is that increases in CO2 will cause directly proportional increases in temperature, then your understanding is limited to a simplistic view of a very complex system. And I haven't even begun to talk about natural effects of cooling or warming or other effects like ocean circulation patterns.

You've been told it's cut and dried and simple as pie. As a skeptic, I find there are too many unanswered factors and assumptions made to be sure that CO2 is a major factor compared to natural causes. And further, other effects of humans on the environment like land use and construction of cities has an impact on warming and we simply don't know the extent of this impact.

Yes, some skeptics claim it's a hoax or a conspiracy and some are so political they don't believe anything the government says. That doesn't negate the concerns of all skeptics. There's kooks on both sides of the equation.

I could write a book about what AGW deniers don't understand.

But as bob326 pointed out, in most cases it's willful ignorance. It's not like the information isn't out there. Though it could have been more precise, "An Inconvenient Truth" does a good job covering the basic science. If a person isn't willing to pop in this DVD and sit on his butt watching the film for a couple hours, they're probably just not interested in learning about the subject.

And while there are a lot of people who are simply ignorant of the basic science, most deniers understand at least the basics. And yet the denier on this site who is awarded with the most 'best answers' doesn't even believe CO2 is a greenhouse gas, and has said all climate scientists are liberals, and all liberals are mentally retarded.

Ultimately there are different sorts of deniers. There are the kinds of deniers who come onto sites like YA and try and misinform people. These folks are willfully ignorant and absolutely refuse to learn the basic science. Then there's the folks who simply haven't taken the time to understand the basic science, even though the information is easily accessible. Many of them deny AGW because Glenn Beck says it's all a scam. Maybe there's some hope in informing these people, as you suggest, but personally I think if they're not willing to take a few minutes to learn some basic science, you're going to have a hard time teaching them anything.

I agree completely, especially with your last paragraph. Unfortunately, the level of scientific education in America, and especially among deniers, is astonishingly low. The claim that ozone depletion is the cause of global warming is something I see far too often. Or that volcanoes emit more CO2 than man.

But if I run across someone attempting to refute the basics of AGW and I offer up a slightly more technical reference describing the process in detail, I get the feeling that few if any take the time to look through it. In some cases the math may be too daunting, in which case you shouldn't be arguing the science without understanding it, but in others, it's willful ignorance. If they want to stay ignorant, that's fine, but to continue to argue the basics of AGW is denial. A good example is the 3rd top contributor in the GW section. I typically don't respond to this particular answerer--he probably thinks I'm Rockefeller himself--but even at this point in time he continues to argue that CO2 is not a greenhouse gas. There's no hope with that one.

It's an interesting question. Denial-ism in itself is an interesting topic. I have been dealing with creationists for years as a biologist, and the patterns seem quite similar.

It's not like the more intelligent/better informed "skeptics"/deniers have not had this stuff explained to them before; many of them have. The interesting question is why some of the ones who are more intelligent look at the evidence and reject it.

What the masses follow is probably closer to your assessment - they don't understand it for the most part. But the truth is that their seems to be an incentive not to understand it. Perhaps it is as shallow a reason as not wanting to change. Perhaps it is grounded in a genuine belief (right or wrong) that any attempt to fix the problem will be worse than doing nothing.

Still, to me, I believe the more interesting problem is why the intelligent ones deny it. Certainly many have underlying religious and political motivations - I'm sure many are subconscious. Perhaps a lot of the denial-ism we see now days is part of the democratization of science that has become more available in the information age. Perhaps some is due to a mistrust of authority (after 8 years of the Bush administration, you can almost understand that one).

Anyway, I think it is something we need to look at. Michael Shermer of Skeptic magazine looks at this very issue quite often. He has written many books around the subject.

One thing I've noticed is that many of them believe that they DO have the right scientific view. Of course, like creationists they usually do not have very convincing answers as to why the vast majority of scientists in the field do not support their views. They usually fail to understand their is a reason for this. You can take a look at some of my previous questions for examples of this.

How do we get rid of water vapour which is much worse than CO2 in its green house effect and much more abundant.

yes, they understand. they still don't agree with you.