Anthropogenic Climate Change - What's in Dispute?

I've been debating (if you can call it that) with two global warming deniers - "skeptics", they call themselves, although what they're doing bears no relationship to skepticism as I know it - and what I can't get them to answer, exactly, is what part of the consensus science on global warming it is that they dispute.The issue, as I see it, is fairly simple. The Earth's climate is obviously a difficult thing to model accurately, but in principle, global surface temperatures come down to basically two factors:1) The heat that comes from the sun ("insolation"), and
2) The degree to which that heat is either retained in the Earth's surface and atmosphere, or reflected back into space.I think it's safe to say that these are the two predominant factors that affect global surface mean temperature.Insolation can be easily measured by space probes and other measurements, and it seems to me fairly trivial to get a sense, over time, of the gas composition of the atmosphere. That's just a matter of chemical gas analysis from a bunch of samples. The Earth's atmosphere is sufficiently turbulent - i.e. weather - that gases should be fairly evenly distributed.Also, the chemistry of burning fossil hydrocarbons can be discerned by a freshman chemist; the products of that reaction are not unknowns. It's also not unknown roughly how many such reactions occur in the course of a year of human industry. This is just a problem of gathering data and making calculations.Again, another area where the science is pretty established are the physical properties of carbon dioxide gas. Since the gas was discovered about 150 years ago it's been the subject, obviously, of countless experiments and its properties have been extensively examined.So, it's not clear to me how the basic, skeleton claim of anthropogenic climate change - essentially, human-produced gases like CO2 increase the "greenhouse effect" and cause the atmosphere to retain more of the sun's heat, causing warming - could be disputed. To dispute that claim would be to assert, essentially, that human-produced CO2 doesn't enter the atmosphere; that it just "disappears" and a purely natural source of CO2 is magically substituted. Certainly we can dispute the extent of the warming, and various models return various minimum and maximum projections for the future, but the denialist's position that no change will occur seems predicated on magical thinking, not on evidence. And it seems to fly in the face of the simple physical properties of the planet we live on and the materials out of which it and it's atmosphere are made.I guess what I'm asking is - what's the debate about?

Also, it'd be funny to hear the most ridiculous objections and conspiracy theories of global warming deniers that people have come across. A guy I used to talk to on the internet was adamant that the whole global warming issue came about because the professional scare-mongers realized that, with global warming, they could use graphics that were predominantly red in color, and it's well-known that the color red makes things more eye catching.LOL! Sure, buddy, that explains it.

Did they write Kyoto? I assumed (you know, from the name) that the Japanese had some involvement in it. But you're saying it was all an Sino-African plot to hobble the first-world economies?

No, it's actually a well-understood consenquence of Mars' orbital inclination eccentricity - which is most definately not happening on Earth. (You may have noticed that we don't have polar caps made of solid CO2.)But, you know, don't let the facts get in the way of a good misrepresentation, especially in this thread. The "Mars global warming" is definately a golden oldie for GW denial types. Good catch!

From what I've read, it's getting warmer now than it's been at any other time in human history, above and beyond the historic, cyclical temperature variation. In other words it looks like we hit the normal, cyclical high point - and then it kept on going up.I'd say that's abnormal. I don't see the point of that, exactly. More is more. It's not like anthropogenic CO2 just disappears. Anything we produce is an addition to the normal atmospheric levels of CO2. Why? There were no human civilizations during the Cambrian. True, but man's direct contribution to atmospheric water vapor levels is negligible; moreover, water vapor doesn't force climate change, it's a feedback of climate change. Water vapor is too heavy to remain in the atmosphere for long; excess water vapor returns to the Earth as rain, obviously.But there's no such precipitation for greenhouse gases like CO2 and methane, which human industrialization creates many millions of tons per year, which is why those gases are so significant to the discussion. Water vapor is significant only as a feedback of climate change since it can't really force climate change on its own. Well, I'd definitely disagree with that. I doubt there's many more climatologists now than there were, say, 40 years ago; before global warming they got along just fine, didn't they?And you seem to have a completely wrong idea about the scientific grant process. You don't "make money" from research grants. You don't even get paid from your grant. So it's just not the case that there's any "money to be made" from global warming - except by denying it. (That money, the money oil companies pay to their misinformation mouthpieces, you can spend on anything you want.) No, deserts grow when the temperature rises, and the modeled effects on agriculture are devastating. Not to mention the rise in ocean volume from both thermal expansion and melting land ice. If you live on a coastal city you might be very much against that.

Well economists can't come to any kind of agreement on that. (Not surprising; economics isn't a science, it's a kind of philosophy.)But you did directly assert that the third-world economies want to limit the first-world ones. Did you have evidence for that, or not?