The reality is that every model I've read seems to predict that positive feedback loop (ie accelerating change at an accelerating rate), as well as other significant non-climate related problems of unrestrained CO2 emissions like ocean acidification. See, carbon dioxide dissolves in water to form carbonic acid, screwing with pH levels and thus the chemistry of the ocean. That causes problems with trophics, you start screwing with life at the bottom of the food chain, and well, I shouldn't need to explain anything else, this is pretty much Grade 9 science.
The thing I don't get is why some people get all up in arms about the concept of ecological stewardship. That we have dramatically altered the planet is undeniable, and that the repercussions of doing so are potentially very severe is equally obvious. One wonders when we'll wind up like the guy on Easter Island cutting down the last tree. As the quotation, attributed to various people, goes, "Only after the last tree has been cut down, only after the last river has been poisoned, only after the last fish has been caught... Only then will you find that you cannot eat money."
And more interestingly, there's simply a lot of money to be made in the process of altering our consumption patterns to be sustainable. The technological development potential is huge. I'm in the process of planning to build a house, and the technologies I am looking at to incorporate into my design will add to my building costs potentially but in the long run (and not even that long, really, a matter of a few of years in most cases), the money they will save me makes them completely worth it. Things like ICF construction, drain heat recovery systems, all fascinating to me, and good investments if they keep my costs of home ownership down and happen to reduce the amount of fossil fuels that I consume. Same with my choice of car (a diesel engine, I wish some of the diesel-electric hybrids sold in Europe were available here). In Nova Scotia where I live I don't know if a plug-in hybrid would be a good option given that virtually all our power comes from coal, oil, and gas, but once I see how they pan out for reliability it's also something I'd give a serious look.
The massive amount of money being pumped into trying to claim that CO2 isn't a problem by those who stand to lose if we shift our consumption habits is what seems to be distorting the discussion. Look at the effort to vilify "The Story Of Stuff", a rather simple video about sustainability which I cannot seem to find anything factually incorrect about... it's just "inconvenient" to suggest that we can't go on consuming resources forever when they are finite. And the fact that people still talk about "Climategate" as though it meant anything is just showing the power of that lobbying effort.
Capitalism and environmental stewardship can coexist - but the reality is that regulation must force them to for the time being though I think over time the free market will accomplish much of what's needed as people learn more sustainability and realize that the choices are actually workable (or better).
