I finally got around to reading this entire thread (seems familiar -- wasn't there a similar thread 6-months ago?) and eventually I thought gee, this sounds like the old "the earth is flat"/"the earth is round" argument that occurred a 1000 years or so ago -- and only took 500 years or so to resolve. As I recall noted scientists of the day were absolutely sure they were right.:D
As to global warming, it seems to me that:
- There's valid empirical evidence that the concentration of greenhouse gasses are increasing and the ozone layer is reducing.
- There's little doubt that man is contributing significantly to the addition of certain of the gasses.
- There's convincing evidence that the earth is going through one of it's cyclical warming periods.
- As to whether man's contribution is significantly affecting the warming cycle, some are choosing to believe that it's overwhelmingly significant, others reject the significance, and still others don't give a rat's ass either way.
I care about the environment and do what I can (my footprint calculation was half of the average, although that was a sad excuse for a "test"). But I refuse to become obsessed with the global warming debate because personally,I believe that the "follow the money" statements are true in that many many people (and nations) will be looking to see how they can make a buck out of this. This distorts the true factual picture.
Since all nations compete between one another, global warming is being used to manipulate and discredit the more powerful nations to give the lessers a leg up in their world standing. Such actions affect the balance of trade and world opinion between nations, all of which can become financially rewarding to some and discredit others. It becomes a very powerful diversion if a nation can be goaded into taking costly extraordinary measures to reduce their GHG contribution. That, in turn, can easily be capitalized upon by the lessors. I don't believe for a moment that the world's nations would hesitate to play such a card to gain advantage. It's very hard to discern who is being manipulative and who isn't, so again the factual picture gets obscured in some ways.
I've read many of the pro/con arguments and remain unconvinced either way as to how much effect man's contribution is having in the overall global warming phenomenon. There's lots of theories and hypothesis and seemingly logical arguments supporting both sides. There's very little hard evidence that remains untainted by bias and omission of facts which distract from the intended conclusion. We only have factual weather records for 200 years, give or take. Everything else is derived by implication based on things like ice-core samples, fossils, rock strata, and conclusions that some meteor impact or sun spot activity or other cosmic event that occurred sometime in the same time period (give or take a 1000-years) -- ie, they're not necessarily facts.
The earth's environment is a very complex system that is being modeled by scientists... mostly by conjecture, not fact. Since the input variables cannot be controlled (you can't control sun spots, meteor hits, pine bark beetles that destroy forests, etc.) refinement of the model is slow because it has to be recursed based on observed random input changes instead of controlled input changes. There are so many variables that it is hard to determine how many have changed at once. And there's a huge amount of inertia in the system, so cause/effect often can only be measured over hundreds of years, not minutes or days. Since man's impact has mostly occurred only in the past 100 years, I'm a little skeptical of drawing hard conclusions, aren't you.
And that takes me back to the earth is flat idea. Did the ship not return from it's voyage because it fell of the edge of the earth? Or did it sink? Or did the crew simply mutiny and are now living in Tahiti? It's only hundreds of years later that we knew for sure it didn't fall off the edge. If we find the wreck we will know it sank. We may never know about Tahiti.
I suspect hundreds of years from now we'll know more facts about global warming. Until then, xman and others who feel strongly about your position -- are you on the earth is flat or round side of the global warming debate?
YMMV