The trouble with stratospheric brightening
The existence of a thermostat implies a fight over who controls it
First things first: I think stratospheric brightening is, broadly speaking, a good idea.
This Substack is called One Percent Brighter because if the Earth reflected just 1% more sunlight than it does right now, temperatures would return to 1750 levels. Spraying reflective particles into the upper atmosphere is, in principle, the simplest, cheapest way to achieve this. As climate risks spiral, I think we owe it to future generations to develop the technology to do it safely.
To be sure, there is huge resistance to the idea. So much so that the Biden administration was more interested in making sure that nobody was trying to develop it than in trying to develop it.
Yet I’ve always been struck by how threadbare the arguments usually marshalled against “stratospheric aerosol injection” are: an unholy mix of fear-mongering and anti-science NIMBYism expressed in hazy terms of unknown unknowns.
But that doesn’t mean that there aren’t good arguments against the idea: there are. Very good ones. Good enough to make me question whether stratospheric brightening is viable at all.
They center not on the technology, but on geopolitics.
The shape of the problem will be familiar to anyone who’s gotten into a thermostat fight.
I’m one. Personally, I like a room somewhere in the 20-21 degree range. My wife is much happier at 23 or 24 degrees. So our marriage is an unending guerrilla struggle for control over the thermostat for our heat pump, with me perpetually nudging it down only for her to make a play for the remote so she can turn it back up again.
I love my wife, so this little pantomime never rises much beyond a friendly tiff.
I did not, thankfully, marry Xi Jinping or Vladimir Putin. If I had, and if the tussle was really about agricultural yields or the viability of Arctic shipping, I suspect things might turn quite a bit more tense.
One such scenario—developed in Neal Stephenson’s sci-fi thriller Termination Shock— is a world where lower temperatures threaten the South Asian monsoon, putting India on a collision course with China and the U.S. Stephenson’s novel is built around a “Greenfinger”-type rogue billionaire deciding to implement a stratospheric brightening program without asking anyone’s permission.
The point is, the very existence of a working global thermostat invites a fight over who gets to set it. It’s easy to think of situations where one big power prefers one setting, another big power prefers another, and suddenly the existence of the thermostat becomes a source of international tension.
Given the stakes, any attempt to go it alone would be reckless: if one nation, or even one individual, lunges for the thermostat, global stability would be jeopardized in untenable ways.
In practical terms, this means we would need an international treaty governing global cooling efforts. For the rules to be credible, they’d have to be overseen by an institution with the autonomy and power to enforce them. This global cooling oversight body then starts to sound suspiciously like an incipient World Government.
It is an iron law of international relations that if your solution requires World Government, it’s not going to work.
It is inconceivable to me that countries like China, the U.S., India, Russia, the U.K., Brazil and South Africa, countries that can’t usually agree on anything, will somehow develop enough trust to hand some of their sovereignty over so a new institution can effectively police global cooling efforts.
There isn’t anything like enough consensus about this stuff to produce a strong oversight body for stratospheric brightening.
Far more likely, then, we would have to settle for a weak oversight body, probably a messy, convoluted, COP-style process, all mediated by the type of imbalanced arrangements we have in the nuclear-power dominated UN Security Council.
It would be cumbersome, possibly corrupt, certainly bureaucratic, full of messy compromises. It would have to compensate countries that lose out, and the fights over how to do that would be bitter. It would certainly trigger passionate opposition, with raucous protests wherever it held its summits. Just like the Security Council, superpower tiffs would cause frequent paralysis. It would make mistakes —lots!— and it would be blamed for weather disasters, whether it was really responsible for them or not.
This is not, in other words, the hopeful new world order that some might wish for.
But then, reality was never going to be like that.
People aren’t ready to have this conversation yet. I know. But they’re going to have to get ready. Because for all the drawbacks and half-measures, even a messy, UN-mediated stratospheric brightening project might still achieve the one critical goal that we can all agree on: preventing our home from becoming uninhabitable.
While you and your wife might disagree as to the optimal setting of the thermostat, my guess is that you'd both **really** rather have a thermostat to argue about than have no influence over temperature at all. I suspect that arguments over exact temperature setting are a higher-quality problem than having no ability to intervene.
Moreover, the costs to increase albedo are likely to be huge and the benefits disbursed and difficult to measure. My intuition is that the problem will be getting nations to chip in, rather than suppressing nations that step up with too much enthusiasm.
The question you raise is discussed in a 2011 article in _ Climatic Change _ linked at:
https://dash.harvard.edu/bitstream/handle/1/4737323/Seitz_BrightWater.pdf;sequence=1
which points out that while many damn geoengineeering , few object to mitigating local warming by brightening roofs,walls and roads, and raises the question of how policy paradigms might shift if , like politics, all geoengineering were local?
Many regional water problems are as amenable to solution by local albedo management as the urban heat island effect, because water is easily brightened by air: parts per million of it can double the solar reflectivity of reservoirs & canals to cool thier contents and cut evaporative loss .