@Santos:

In your post "I don't get it", you have shown that you seriously don't get it:

"Hot or heated air rising from the earth simply has to pass into the cold reaches of outer space."

Wow. No! You've betrayed a complete lack of understanding of buoyancy, gravity, and mass balance. Basic physics. The air sticks around. It cools off, sinks back down. Think about heating soup in a pot to get the idea.

the air still sweeps past into the cold infinity of space no?

Answer: No. See above.

The air and a good deal of the heat sticks around.

You clearly do not have a grasp of the most basic physics behind our climate system. I sincerely ask that you sit down with a basic meteorology textbook or something before you embarrass yourself again. Seriously. Then you might want to read this paper:

http://www.globalwarmingart.com/images/1/18/Arrhenius.pdf

It was written by Svante Arrhenius over 100 years ago. The paper is called "On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground." It's about how adding CO2 to the atmosphere traps heat. You can be rest assured that Arrhenius was not blinded by political correctness or anything like that. The amazing thing is that his calculations for the sensitivity of climate to CO2 concentration are reasonably consistent with the current science- not bad for a dude with no calculator.

I am amazed. You've posted something like 10+ letters on this article, and it's clear that you don't understand the underlying science, at all. Please- empty your head and start again.

Which is a shame. Most people view the issue of man-made climate change through their worldview (I am reminded of e.g. George Lakoff's strict father/nurturing parent example), and it either makes sense or does not. The science takes so much time to understand that it's much easier to pick the position that fits the rest of one's worldview. I have an MS from MIT in environmental science, follow climate science to some degree, and still have at best a tenuous understanding of the major moving parts of the global climate system.

Even though I just said few are willing to look at this topic with an open mind, here's my attempt to summarize things simply and rationally:

1. The sun is an important factor behind the climate system; no one says otherwise. But here's the problem- for the sun to make the earth *hotter*, it's gotta get *brighter*. It hasn't been doing that, at least not nearly enough to explain the temperature rise we've seen.

2. All else equal, adding CO2 to the atmosphere traps more heat. Arrhenius quantified this over 100 years ago. There's no question that humans are responsible for the current rise in CO2 in the air. You can look at the amount of carbon burned in fossil fuels, and the amount of additional CO2 in the air. In fact, there's less in the air than there should be; that's because a bunch has been slurped into the oceans (causing the pH of surface waters to drop, but that's another topic...).

So: For man-made global warming to *not* be a problem, you pretty much have to show that the climate will somehow negate #2 on its own (or predict that the sun is going to cool off). Lindzen has his theory (the iris effect) which inconveniently doesn't really have any data behind it quite yet. Broecker (a kick-ass scientist, by the way) says the climate is "an ornery beast."

My take is that the climate system or the sun *may* bail us out, but I'm not holding my breath. I think in the face of this uncertainty the best course of action is aggressively pursue a "least regrets" direction of conservation, cost-effective renewable energy (e.g. offshore wind), aggressive investment into solar (which the private sector has done nicely- some predict grid-parity in 5 years- overly optimistic, but encouraging), some sane biofuels, etc.

It doesn't have to be that difficult if people get with the program.