Key points:

  • Simply reducing emissions is not enough; “if you’ve dug yourself into a hole, you don’t just stop digging, you need a ladder”. I.e. we need to reduce greenhouse gas content of the atmosphere and/or reduce global temperature.
  • Waiting for the biosphere to reabsorb the carbon liberated over the past centuries is a matter of further centuries. We need to take counteraction to break the positive feedback loop we are already seeing.
  • Two proposed fixes: dumping crop waste to the ocean floor rather than letting it biodegrade and release carbon back into the stratosphere; and releasing aerosolised sulfur into the atmosphere, initially above the Arctic for testing purposes, in order to reflect solar energy back into space.

Greg Benford is a very smart guy, and I was impressed by his presentation and the ingenuity and efficiency of the two key ameliorative techniques he presented. Many of my reservations were addressed. (Doesn’t dumping crop waste sequester elements other than carbon? Turns out that the particular waste types he’s proposing dumping, particularly corn stalks, don’t have much else in their composition. Doesn’t transporting the waste create more emissions? Not if you use river transport, which efficiently lets gravity do most of the work. Won’t there be effects on seabed biospheres? They’re studying it but it looks like there is little long-term harm. Doesn’t pumping sulfur into the atmosphere increase the risk of toxic/acid rain? Yes, and over decades the pH of the ocean will change, but there are other measures to counteract that… and the breathing space we get will enable us to concentrate on finding other tech to fix the core problem.)

However there are still a hell of a lot of questions there was no time to ask. How much will stratospheric sulfur precipitate, and what effect will that have on ice melt rates? (Is it like salt, which accelerates melting? That would be my assumption.) Are the metal frames which held the bales of sequestered crop waste in the study necessary every time? If not, does their absence change anything?

He was also far, far too acquiescent in the existing economic models that are precisely to blame for the problem. He kept talking about what is “affordable”; one of the key jobs for scientists, in my view, is to debunk the economic models that hold that minerals in the ground and – particularly – trees in a forest have no economic value until they are ripped out and injected into the human production chain. It’s the same mentality that makes a heart attack a hundred-thousand dollar boost to the economy – all that surgery, medication and equipment, isn’t it awesome how much money has to be found! The way to get the infrastructure we need to fix the problem is to ensure that the costs of inaction are accurately included. It isn’t that long ago that economists were seriously, unironically writing that they couldn’t see how a global temperature rise of even several degrees would have any major effect on industry, other than maybe increasing aircon bills in factories a bit, and agriculture would just have to shift specialities to the new climatic realities for their regions, but that wasn’t a big deal, people change crops all the time. Trying to muster resources to deal with the new realities in such a twisted framework is unnecessarily hard work, if it’s possible at all.

I’m also sick of the internal jockeying for who gets to be the heroes in this. Yes, engineering solutions will be indispensible to dealing with the problem. So will political and economic reform to reduce energy waste and excess emissions; there is no way around that either. As I think I mentioned in a post yesterday, greenies are usually pretty OK with technology having some part in dealing with the problem, though they do exhibit a certain wariness about further large-scale interventions. But given the history of humanity’s dealings with the environment, that’s kind of understandable, and unless confronted with absolute intransigence, I regard that as proper scientific scepticism. I’ve yet to see the equivalent of the claims I’ve seen here, that it’s “an engineering problem” (with overtones of that being the only significant part of the problem). I’m not saying that kind of crap never happens – I’m not exactly a central figure in these debates so I’m sure I’ve missed that sort of stuff – but either way it’s not like we can afford to be neglecting any avenue of attack on a problem of this scale and complexity. That means we need mutual encouragement and support, and joint action against the human systems that caused and sustain the problem, not territorial pissing contests. (Excuse the fused metaphor but I think the blend is not inappropriate… aside from the urinary element.)

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