Global Climate Change

JS (an old friend from High School who just found my blog, btw) and a few others have asked about my views on global climate change. I'm traveling at the moment, but have had a little time to phrase a short, non-lecture on my views. I'm going to avoid, for the sake of nit-pickiness, a lot of the boring details, in part because there are other resources on the net and in part because I don't want this to be a lecture.

Things I think are true:
1) The climate is changing. Lots and lots of evidence over the last 250 years suggests this is true. We definitely exist in a period of history where the climate is undergoing a change at faster-than-geologic timescales. How it's changing is less clear as is why it's changing right now.

2) It's getting warmer. Yeah, yeah there are studies here and there which show things like increased thickness in some part of the Greenland ice sheet etc. however the overall trend over the past 50 years is towards significant warming. A piece of Antarctica the size of Rhode Island broke off last year for Christ’s sake! The climate is a complex, non-linear system with a so many self-regulating feedback loops we can't make any kind of detailed prediction about local reactions. The Greenland ice sheet maybe getting a little thicker, but clearly the seawater is warmer and overall planetary ice coverage is down. One of the annoying things the conservatives do is equate the little with the big to make it look balanced. Context is everything, and in the context of warming, all kinds of non-immediately intuitive things can happen. It's like doing physics in a non-inertial reference frame. Your assumptions, while often true, are not always true. Climate change is similar

3) Some part of the warmth is due to industrialization. Its very clear that greenhouse gasses cause temperature increase. Yes, some folks at Exxon will debate that but please, the science has been in the bag on this for half a century. In the 50's they were thinking they could build weather control machines based on emitting or absorbing Co(2). Chaos theory put a pin in that, but the science on CO(2) was strong enough to invite that kind of speculation. We’ve dumped a lot of greenhouse gas into the air, there has to be some reaction.

4) We may not be able to do anything productive to halt the change. It's not clear what should be done. I'm guessing if we stop dumping CO(2) into the air at pre-Cambrian rates, it will have some net positive effect, but I don't think anyone knows. I used to think we could scrub out the CO(2) by locking it into solids again. Imagine a car that had a converter in it that actually locked up more CO(2) into a carbon brick than it emitted into the air. Cool huh? However, the Earth's climate system is in full repair mode now. Suddenly removing the gas might cause it to swing too far the other way, resulting in a loss of nearly all greenhouse warmth. This becomes the "white earth" scenario very quickly and all our (admittedly poor) climate models suggest it's hard to get out of the "white earth". It’s not clear yet what to do, how to do it, or even when.

5) The rainbelts will continue to migrate northward as the problem gets worse. Something clear in both the analog and digital modeling of the climate.

6) The earth is not guaranteed to be habitable to our civilization. Sorry folks, it just isn't. Mankind will probably survive anything likely to happen, but civilization is not guaranteed.

7) It will probably take 50-150 years for the bite to really sink in, and it's probably too late to do much about it. The thing about chaotic systems is that, once they switch modes, the new modes look a lot like the old ones for awhile, even though it's too late to do anything about it.

In a short piece, thats where my head is on this. Feel free to correct or debate me.
oh, and

8) No, it's not variations in solar luminosity. The Sun is not a Cepheid variable, is a Zero Age Main Sequence Star (ZAMS). People suggesting this really out to take an astronomy class for actual credit. This one is my pet peeve because people who know nothing about astrophysics throw this off as an excuse not understanding what they are saying.