Last week we looked at the all-but-hopeless prospects for cutting greenhouse gas emissions massively enough, and quickly enough, to avert a climate catastrophe that’s looming more imminently than most people realize. New data point: voters in Washington State, one of the most liberal, pro-environment places you’ll find, just voted overwhelmingly against a carbon tax ballot proposal pushed hard by its Democratic governor. If seemingly progressive voters in the US aren’t willing to raise their energy costs, how can we expect India, China, and Africa to jump on board? The international body in charge of such things tells us that if we don’t slash emissions by 45 percent in the next eleven years, we’re toast. Since we’ve never cut them at all—instead just watched them go up while wringing our hands—this seems to no longer be a plan to consider.
There is an alternative: deliberately alter our atmosphere by loading it with reflective materials to keep sunlight out, creating a cooling effect to offset the greenhouse gas warming effect. At the moment, sulfate aerosols are the leading candidate. There are good reasons to think this could work, at a hundredth of the cost (maybe even a thousandth of the cost) of cutting emissions. The cost is so low that many countries, and even a few individuals, could do this unilaterally.
So what are the downsides? Quite a few.
1. It would be nice if we could test this out on a few other Earth-like planets first, just to see what actually happens. Right now, all we have are educated guesses because no atmospheric testing has ever been conducted. “Gee, who would have thought that ___ would happen?” is not what we want to hear once we’re several years in. A new Ice Age, for example, would be a bad thing. So would surprise crop failures, if it turns out that too much sunlight is being blocked.
2. Once we’ve started down this path, we cannot turn back. Picture a room with both the radiator and the air conditioner running full blast. The overall temperature, if you can get the air circulating, might be quite comfortable. But if you unplug the air conditioner, even briefly, the heat will quickly become unbearable. That’s what will happen if we start with sun-blocking aerosols and don’t keep them up.
3. There’s a good chance that once this initiative has begun, whatever pressure there is now to limit greenhouse gases will evaporate. It would be nice to say “We’ll just artificially cool as a stopgap for a few years, until we can get the emissions under control.” That’s most likely whistling in the dark. Once we’re in, we’re in for good.
4. Who governs the process? Who decides what precise sunlight reflector to use, and how much, and when, and where? Different countries may have different axes to grind. Russia and Canada, which have some reason to welcome a little warming, may have a different point of view from Bangladesh and the Netherlands, which may disappear if sea level rise predictions come true. Whose thumb will be on the scale?
5. Every time a hurricane or other severe weather event occurs nowadays, you can be sure tongues will start wagging, blaming it on global warming. How much of this is true is tough to prove—we had plenty of severe weather long before the current warming began. You can take it to the bank, though, that once we deliberately start tinkering with the atmosphere, the level of complaints will shoot through the roof. Whatever control board (if any) is in charge will be vilified by every region and special interest group that thinks, rightly or wrongly, that its weather is not as good as it deserves to be.
6. Warming isn’t the only negative effect of greenhouse gas emissions. Our oceans are becoming more acidic, to the detriment of many species. Artificial sunlight reflection might cool the earth, but it will do nothing about ocean acidification.
These are legitimate, serious objections—maybe deal-killers. There are other objections that are far less worthy. Expect God experts to argue that the spirit in the sky, not humanity, should be in charge of controlling climate. This is nonsensical, because humanity is already having a tremendous impact—what’s being proposed here is to deliberately offset what we’re doing, in a manner we can afford.
Another non-worthy objection is essentially masochistic. Some people seem to enjoy wallowing in guilt, wringing their hands at everything that makes humans comfortable or happy. A solution to global warming that doesn’t involve a massive reduction in creature comforts will leave them frustrated. Humanists need to be clear-headed, doing what’s smart to achieve both short and long-term happiness, based on the best evidence we can gather. Yes, we need to act with regard for future generations as well as ourselves, and for the other species that enrich our lives. But self-denial for the sake of self-denial is nonsense.
Nevertheless, the technical objections are serious—especially the first one. As far as we know, the technology has never been tested in the atmosphere. There are computer models, but that’s not even close to good enough.
I see our choices as follows:
1. Let the warming happen, and hope we can cope with it OK.
2. Keep beating the dead horse of emissions reduction, dreaming that humanity will turn on a dime and suddenly start spending tens of trillions while trashing its standards of living. This will almost certainly get us to the same place as option #1, but at least liberals will be able to say “We told you so.”
3. Jump right into geoengineering, based on existing computer models, and hope we don’t have any “Oops” events we can’t handle.
4. Ramp up the study of artificial cooling techniques—hard, and fast. The Manhattan Project produced a working atomic bomb in four years’ time after the president said “Go.” NASA put humans on the moon in seven. That’s about how much time we have to get our act together to fend off warming, a problem with vastly more complex political ramifications. “Study,” by the way, means real atmospheric tests, not just computer simulations.
5. Wait for China (which is already planning to put up artificial moons for street lighting, to go with its artificial islands) to act unilaterally, without the knowledge or experience we need to pressure them to act more responsibly.
I’m for #4. If intense study and real-world experimentation turns up an insoluble problem, the sooner we know that the better.