Whose cloud is it anyway ?

I really don't understand the most militant climate activists who are also opposed to geoengineering. Or rather, I think I understand them (or some of them at any rate), but I don't understand what their goal is supposed to be.

To a certain extent of course it makes good sense. The basic thinking that we've messed things up, so the best thing we could do is to step back, isn't unsound. It's completely natural to assume that because we got things so very badly wrong before, any further, deliberate intervention has a serious risk of making things very much worse. It could even be hubris to assume we're capable of getting things right, such is the complexity of the system we're dealing with.

I'm not unsympathetic to this view by any means. Anyone who is not merely advocating but actively gung-ho about the prospect of trying to alter the climate is someone to steer clear of. What I don't get is not the skepticism, but the denialism. And many of the reasons claimed for opposing geoengineering in principle (rather than objections to the specifics, which are often legitimate) are, so far as I can tell, a terribly toxic mixture of naivety and cynicism.

The most common retort is that geoengineering will distract from the more important business of cutting emissions. This, I think, is wrong-headed for a multitude of reasons. First, geoengineering takes many forms, and I'd argue that deliberately rewilding, planting trees, encouraging sea grass and other growth, all fit the bill of actively changing nature to help reduce the CO2 content of the atmosphere. And these solutions clearly aren't opposed to environmentalism in any sense : quite the opposite, they are perfectly aligned with classical environmentalist movements.

Second, how exactly are we supposed to reduce the existing CO2 without inducing the removal of carbon ? We have, so the claim is, already done horrible damage, but apparently we should now just back off and leave well enough alone. This is like going into someone's house, breaking all their furniture, starting a small fire in their dustbin but then slowly tip-toeing away claiming you don't want to make things worse. It doesn't make a lot of sense to me; if you make a mess, you have a responsibility to clean things up (or at least to try). I find it extraordinarily strange to claim that we've done such awful damage but shouldn't try and repair it.

And thirdly, our efforts to reduce emissions have been pretty pathetic so far. Yes yes, you can whine about overthrowing capitalism or some other damn fool idea as much as you want, but it isn't helping : it's schoolyard politics. The point is that geoengineering solutions appear to have little or nothing to do with this, and it doesn't look at all likely that if we took all the money away from geoengineering research we'd really invest it in other energy solutions instead. That idea seems crazy-naïve to me.

Which is why I don't understand what the goal of the opponents is supposed to be. Live in a shitty, overheated planet and make the best of it ? Sit back and watch everyone and everything suffer horribly ? That prospect is surely crazy-cynical, the product of people who've had the hope beaten out of them. It's daft.

No, the right solution seems clear : diversification. More than any other this feels like a situation where the idea of a single magic bullet is never going to work. Instead, we need to try and cut back our energy requirements wherever possible, change our energy production methods, change our farming techniques, change our construction strategies, work to a controlled decline in the population (otherwise Nature will do this for us, except it won't be controlled), and, yes, actively solicit the removal of atmospheric carbon. The idea that we can just, somehow, stop emissions tomorrow and that alone constitutes an acceptable solution is frankly bizarre. We know that simply isn't going to happen and it wouldn't be enough anyway. Pretending we should be singularly focused on this outlandish objective, at the exclusion of all others, is hindering the cause, not helping it. It's an outrageously unrealistic goal which distracts from what we really need to do, which is everything.

Which is not to say that some geoengineering "solutions" aren't a hell of a lot more scary than others. For example, injecting sulphur dioxide into the atmosphere to obscure the sunlight just slightly. The NYT piece linked doesn't have much in the way of data but some choice quotes :

“There certainly are risks, and there certainly are uncertainties,” he said. “But there’s really a lot of evidence that the risks are quantitatively small compared to the benefits, and the uncertainties just aren’t that big.” The only thing more dangerous than his solution, he suggested, may be not using it at all.

Once solar geoengineering began to cool the planet, stopping the effort abruptly could result in a sudden rise in temperatures, a phenomenon known as “termination shock.” The planet could experience “potentially massive temperature rise in an unprepared world over a matter of five to 10 years, hitting the Earth’s climate with something that it probably hasn’t seen since the dinosaur-killing impactor,” Dr. Pierrehumbert said.

On top of all this, there are fears about rogue actors using solar geoengineering and concerns that the technology could be weaponized. Not to mention the fact that sulfur dioxide can harm human health.

Dr. Keith is adamant that those fears are overblown. And while there would be some additional air pollution, he claims the risk is negligible compared to the benefits.

To be clear, I'd probably put this way down my list of preferred geoengineering solutions. Injecting chemicals known to be harmful is, pretty obviously, not exactly the ideal solution. But all the same I take great issue with :

Raymond Pierrehumbert, an atmospheric physicist at the University of Oxford, said he considered solar geoengineering a grave threat to human civilization. “It’s not only a bad idea in terms of something that would never be safe to deploy,” he said. “But even doing research on it is not just a waste of money, but actively dangerous.”

Now this is extremely foolish. Consider the trajectory of the climate. Now consider what happens if (or rather when) we fail to reduce emissions and things get bad. What exactly do you think people will do then ? It seems to me that when pushed, there is every chance that desperate people will look for desperate solutions. Only, if we don't do the research now, future generations may implement it regardless, heedless of the unknown consequences because that is exactly what desperate people do. Better by far to research this now while we have time. Do as many simulations as possible, run controlled tests where possible, monitoring how the chemistry changes in laboratory-reproductions of the upper atmosphere and eventually in small-scale open tests. Likewise :

Then a professor at Harvard, Dr. Keith wanted to release a few pounds of mineral dust at an altitude of roughly 20 kilometres and track how the dust behaved as it floated across the sky. A test was planned in 2018, possibly over Arizona, but Dr. Keith couldn’t find a partner to launch a high-altitude balloon. When details of that plan became public, a group of Indigenous people objected and issued a manifesto against geoengineering.

Three years later, Harvard hired the Swedish space corporation to launch a balloon that would carry the equipment for the test. But before it took place, local groups once again rose up in protest. Within months, the experiment was called off.

“A lesson I’ve learned from this is that if we do this again, we won’t be open in the same way,” Dr. Keith said.

That last is pretty sinister. Either we can approach this rationally and sensibly and have controlled, transparent research, or we can respond with knee-jerk, absurd levels of ideological purism and reap the whirlwind. We are going to need geoengineering research : in this technique, in all techniques, because we need as many solutions to the climate crisis as we can. Nothing less is adequate.

(Note : I say research. Not necessarily this particular solution, which I'm instinctively against. But not investigating it at all, not even considering the possibility without any actual data to back up the objections, that's mad. Even more so for other solutions which can be much more limited and controlled in their affected area, e.g. algal blooms in reservoirs.)

A second, more academic article explores the prospect of marine cloud brightening. Instead of making the sky darker, it proposes injecting small amounts of salt into clouds to make them more reflective. This would still not be among my top priorities for geoengineering (I think those would probably be rewilding and direct carbon capture) but salt is at least a lot better than sulphur dioxide. That article is also much more measured, setting out a detailed program for how practical tests could proceed and when they should stop. It also makes it clear that it would not be, by any stretch, any sort of "quick fix", with the results possibly not known for decades. Which is exactly why we should start as soon as possible. It might also help us better understand how particulate matter in the atmosphere behaves more generally, something we're been doing anyway... better, surely, to study things in more controlled conditions than making observational inferences where there are numerous confounding variables.

Well that's really all I wanted to say on the matter. It's right to be cautious about geoengineering schemes, but it's silly to treat them as all being equal, and foolish in the extreme to restrict research on any of them. We need to do this now while we can still can. Otherwise we may find ourselves in a situation where we don't have the luxury of investigation at all.