As I'm aware, the trend is considered proven. The "why" and "what/any/bad effect" is in question.

Oh, kiss me, you mad fool!

I knew it! I knew it, I knew it, I knew it!

PS - I think I laughed so hard that I shot sherry from my nose. And it burns.

Bill is very correct on both accounts. I am going to take off my flaming leftie hat and put on my scientist hat for just a minute here (warning, rant coming):
There have been many articles over several decades in those reactionary leftist journals such as Science and Nature that have demonstrated a clear global warming trend (global here means um, global, not the DC suburbs) and all the modeling using supercomputers from hippie hotbeds like NASA and Lawrence Livermore Labs, have directly connected the trends to increased energy absorption by the earth over the last century that fits quite tightly with observed increase in greenhouse gasses, and not other variable (remarkably so actually). There is no real debate on this in the scientific world, it is only happening in the media where they get some flaky actor to debate global warming being bad and stuff (while living in a 50,000 square foot air conditioned home) with some slick corporate shill pulling a paycheck from Exxon arguing the other side which is: “no problems here, consume all you want, we’ll make more”. This passes as fair and balanced reporting these days. 99 scientists out of 100 agree and there is a raging debate. Amazing. As Bill said, the argument among scientists is actually how bad is it going to get, not is it happening. An article in this week’s Science Magazine suggests without aggressive action, pretty bad. That bike is looking better and better to me.

And sherry does burn when snorted out the nose.

How bad is it going to get--maybe like 55 billion years ago when both polar ice caps were abt 97% melted? (hey don't believe me--I got this from National Geographic) No doubt the 100 year numbers are correct, but speaking in geologic terms---
so what? Don't you usually have to have a more significant statistical sampling than 100 years out of---what? how many billions--to draw some tentative conclusions? Just askin'

By the way, yeah, I think we ought to get some alternatives to fossil fuels too. We don't need to think the sky is falling for that to make sense.

Here is what I would assume to be the official US gov position as it is on NOAA's website:

http://www.ncdc.noaa.gov/oa/climate/globalwarming.html

It is safe to guess that this is actually a very conservative position in the scientific community as there are likely political forces at play in spinning the info. The fundamental take home is that greenhouse gasses in the last 200 years are rising to levels not seen on the earth for more than 400K years (and these gasses are the primary cause of heat retension), and temps to quote the website:
"Based on the incomplete evidence available, the projected change of 3 to 7°F (1.5 - 4°C) over the next century would be unprecedented in comparison with the best available records from the last several thousand years."
Big changes are afoot, and they are being caused by us. What isn't known and is impossible to predict, is what the final effects on climate will be. But its going to get hotter...

Guys, guys, guys. The global warming thing isn't even metaphor here. It's bait to get Bill into the den, -excuse me- the library, alone, and ply him with liquor. Seems to have worked pretty well. I can only hope the pictures start floating around the net by the end of the day...

Ooohhh, that's how he gets him to ignore the scratchy wool. I heard Bill prefers vicuna...

There is more to the possible global warming trend than just greenhouse gases. First, the sun is more active now than it has been for a long, long time. If the sun is hotter, maybe ... well, even a government educated science teacher might be able to draw that conclusion.

Also, the greenhouse gases were here before? Well, pray tell, what caused them? The cars and industry of 400,000 years ago?

And the ozone layer that was depleting? The crazy right wing nuts said it was a cyclical phenomena, like much of nature. Well, it repaired itself. Which did what? That's right - it helps keep heat in the atmosphere. The ozone layer depletes, global warming goes down. We "fix" it (it fixed itself, but some will claim it is because our deoderant is now stick instead of spary), and global warming goes back up.

What a lovely theory. We had ice ages and hot weather before we had cars and industry, but now it is all our fault.

LB buddy--

You mention Science, Nature, Nasa and Lawerence Livemore Labs as constituting scientific consensus on global warming but describe them as "leftist publications" and "hippie hotbeds"....are you surprised they agree? There is consensus among the scientfic community that global warming is happening but there are many camps, two of which are the chicken littles (of whom you seem to subscribe) and the "we dont know jack-shit about this and shouldnt rush to conclusions yet...", obviously the more sensible. Here are some facts:

1. Around 1000 AD they were growing grapes in Britain...for wine. Im sure thats pretty impossible now. The Earth at this time was about 5 degrees warmer...dun dun dun...than today.

2. The Artic is melting, but the Antartic is actually cooling. Scientists all agreed that a sure sign of global warming was both ice caps melting...hmmm.

3. "Decades" of articles you say? Well, 3 decades ago, during the 70s, scientists were predicting that the human population would reach 50 billion by 2050 (hence the premise of Soylent Green). Now they are saying we wont even reach 10. See how theories change as we learn more?

4. You know all those powerful supercomputers that generate those models for climate prediction? They dont include clouds!!! How can you make models about climate systems without including clouds!?

5. The Mann study was wrong, there is no hockey stick. When we began recording temptures about some 150 years ago, we were still emerging from a global cooling period referred to as the "Little Ice Age". Thus, all tempertures from the early half of recording must be understood as being skewed and reflecting an abnormal, so to speak, situation and not an actual datum of steady Earth temps or whatever.

This is not to suggest that we should go ahead and happily pollute but that it makes no sense, unless you are the MSM, to run around screaming that the sky is fallin when we really dont understand a lot of whats going on. Global weather systems and such are very complicated and little understood--we need more research and better methodology before we attempt to "fix" (or screw up) anything.

Eve---you got it in one--maybe 5--could not have said it better myself. They were not only growing grapes in GB but about the same time were raising cattle in the Hebrides. Also-- in the dear old wacky 70's--remember the guy who said we were experiencing global cooling? I think that was because we were all leaving our refrigerator doors open or something.
Too bad that the perfectly sensible and sane idea of conservation, preserving as much of the earth as clean as we can, has to get so politicized. So counter-productive. All that energy but into hurling the blame, that's what causing the warm-up.

Hi Eve:

The leftist and hippie hotbed quips were jokes. These are clearly conservative careful organizations not inclined to hyperbole, that was just to highlight that this really isn't a left/right issue. My argument is not that future outcomes are certain, as I said, we don't know what the outcome will be, only that there is scientific consensus that there is an anthropogenic increase in global temperature. There is raging debate only outside of the scientific community. Simulations are just that and modeling or predicting future trends are nearly impossible. Therefore the consequences of global warming are unknown. This does not disprove global warming is actually taking place and the fact that it is happening is no longer a debate in the scientific community, only in the media. This is similar to my own area of expertise, biology, where there is a “debate” on evolution. There IS a debate about evolution, but NOT in the scientific community, there is essentially consensus there. You can always find the contrary voice to reinforce whatever view you want, give enough amplification to that single voice and it appears there is uncertainty in the whole community. This is what is happening with global warming. There is a lot of discussion and doubt outside of the scientific community on warming (this thread being an excellent example), but not among scientists. To suggest there is, is disingenuous.
I am not arguing the sky is falling, only that the earth is getting warmer because of our burning of fossil fuels. Grapes growing in England 1000 years ago does not disprove this, it only modulates how we might respond. As with other forms of pollution (which are actually a much bigger threat than the warming issue in my mind), I totally agree with skeptic, the approach should be to conserve and clean as much as possible and not waste time pointing fingers (I am using my AC right now so my finger points at myself as much as anyone). We could argue how hard we should work at cleaning and conserving and what approaches are the best, or even that we should just not worry about it, and that debate is absolutely warranted. What really shouldn’t be argued anymore whether increased greenhouse gasses are creating increased heat retention

Well, I wouldn't say "as much as possible" in the sense that we ought to go back to the caves or lower our standards of comfort, convenience, or hygene significantly (think of the ground water pollution from cave man latrines!) because, for one thing, no one, not even the Swedes, would do it. It seems to me that a great big part of the problem here is that nobody seems to know what anybody else means by 'conservation"--too often the Left comes off sounding like neurotic scolds who equate bodily comfort with original sin, and the Right, to be perfectly fair about it--not a thing I am all that interested in being--reacts
overly defensively, like smog is part of our cultural heritage. Unfortunately we are a People who like Extremes.