I’ve mentioned several times what I call the “Archer bonus” that we’re granting ourselves by artificially limiting our vision to what happens up to the year 2100. Archer is, of course, David Archer, author of the excellent book The Long Thaw. The bonus is 40%, as in 40% of the warming from our emissions up to 2100 won’t happen until after that date. Even if we somehow manage to restrain emissions enough to keep warming to 2C over pre-industrial times by 2100, that means we’ll have another 0.8C in the pipeline.
Personally, I don’t think our chances are good of keeping it under 2C, even before 2100. That’s not a comment born of Copenhagen disappointment, simply my assessment of our political realities–China and India valuing economic growth over emissions reductions, and the US being totally incapable of finding the political will to make the aggressive cuts needed to hit that goal. Another major factor is the steady thrum of bad news on the climate front, not least of which being the recent finding about the surge of methane emissions from the Arctic (see Another methane surge detected). It’s too soon to consider that “the” tipping point or the beginning of runaway warming or however else you want to cast it; but if it is the first step in a major methane ramp up, then there’s nothing we can do to stop it short of some very aggressive geoengineering steps. Simply cutting CO2 emissions won’t be enough, given all the warming already in the pipeline.
All of which brings me back to the question that prompted me to write this: Why are we so sanguine about this arbitrary selection of 2100 as the limit of our planning horizon? As best I can tell, no one seriously disputes the 40% bonus, yet I’ve seen practically no discussion (except for Archer’s book) about what comes after 2100. Are we being willfully blind to this nasty detail simply because including it would make the problem that much tougher to solve? Are we making implicit calculations that even our children will very likely have died before then, so it’s therefore acceptable for us not to care? Or is it yet another thing that got started arbitrarily and then became “the” standard metric for such discussions, only to soldier on, unchallenged?[1]
However it happened, I find it bizarre that so many people are so concerned about keeping warming under 2C by 2100, yet we all but fall mute once the discussion extends beyond that date.
Anyone here have the answer?
[1] I could easily imagine that we fell into the pattern of talking about what happens over the next century, and that morphed into the year 2100 roughly around the year 2000. Since then, it simply became convention and it stuck.
Rather shockingly, this made me realise that my time horizon didn’t extend beyond 2100. It’s an interesting question why. I read about PO/climate change every day; I think about this stuff every day; I couldn’t explain why I live the way I do without referring to PO/climate change (and, it’s true, ecology generally) yet 2100 marks a point beyond which I can’t really think, or if I do, it’s so abstracted from experience and reality that it doesn’t really mean anything. Your post reminded me of some interesting stuff on the Oil Drum a while (a year or two?) back on discount rates and I suspect that the discount value of events beyond 2100 is pretty much zero. It’s got to be, what, a good four generations away so that gives us a pretty limited direct genetic bonus is caring and obviously reciprocal altruism can’t operate over such extended time spaces (not that that’s why we should care but I’m sure that plays a part in explaining why we don’t). Interesting though, and another one to add to the hmm-that’s-pretty-depressing file.
If we go the other way… 100yrs is sort of collective memory. Any thing more than that is history.
Dan: Amazing how easy it is to overlook our own assumptions, isn’t it? I know I catch myself doing that all the time, and that’s why I keep asking questions about things like where the guideline came from that 2C of warming is the upper limit of “safe”. (And for the record, I’m not at all convinced that 2C is the “right” answer, given what we’re learning lately about feedbacks. We could very well find out there’s a “dead zone” in temperature rise, meaning once we get to 2.0C increase that feedbacks kick in and zoom us to 4 or 5C, so there’s no equilibrium we can hit in that range.)
The 2100 thing bugs me a lot because it’s so arbitrary–would we be discussing climate change in terms of the next 64 years if we had 8 fingers instead of 10, and therefore had settled on a base-8 number system? It also feels callous. We’re willing to move heaven and earth and coal plants to stay under 2C by 2100 (at least theoretically), but after that date, hey, everybody’s on their own.