Living with Geoengineering Injecting sulfate aerosols into the stratosphere would cool the planet considerably, so what’s holding us back? Quite a few things.

This past October the Intergovernmental Panel on Climate Change (IPCC) released a report saying that our current course will produce catastrophic results across the planet, including substantial sea level rise, by 2040. Another study focused on the warming that has already occurred in the earth’s oceans and found quite a bit more than anticipated. This means it will be far more difficult than we thought to mitigate additional warming in the coming years. It’s time to get serious.

Plan A for “getting serious” is the same one we’ve been hearing about for the past fifty years. It starts with acknowledging that human activity is a primary cause of the current warming trend, as we’re the ones responsible for emitting more greenhouse gases into the atmosphere, and those emissions trap the sun’s heat. So what we need to do is reduce those emissions and return to the preindustrial conditions in which heat could more freely escape into space.

How much do we need to reduce them? According to the IPCC, to prevent catastrophic warming symptoms, we need to cut the planet’s total emissions by 45 percent by 2030. By 2050, we’ll need to reduce emissions to zero.

I hate to go way out on a limb, but here is a small prediction: it ain’t gonna happen. In fact, despite all the handwringing, all the politician photo-ops, and all the lamentation from the pope that everyone should do without air conditioning, global greenhouse gas emissions are still going up—not down. There was a three-year plateau from 2014-2016, but then they shot up another 2 percent in 2017.

We can’t just smugly point our fingers at Donald Trump either—US emissions were down 0.5 percent last year. They rose globally because of India, China, and growth in developing nations. Africa, for example, is at long last enjoying steady economic growth. That’s great for them, but not for the planet as a whole. The idea that the world will somehow reverse this upward trend and slash total emissions nearly in half in the next eleven years is ludicrous.

Even if we could achieve such a reduction, the reduction in the quality of billions of lives would be massive. The rich would get by OK—they always do. The rest of us, especially the poorest,  would take it on the chin, to say nothing of other species.

What not everyone realizes is that a Plan B for halting global warming does exist. It would almost certainly be orders of magnitude cheaper than trying to cut emissions in half, but it also would have some serious downsides. What humanists should be thinking hard about now is how to steer this solution in the right direction, maximizing the benefits while minimizing the risks.

The gist of the idea is simple: create a cooling effect strong enough to offset the greenhouse gas warming effect. In 1991, Mount Pinatubo erupted in the Philippines and the sunlight-reflecting material ejected from it cooled global temperatures by about half a degree Celsius for the next couple years—that’s a full quarter of what we need to avoid catastrophe. Other volcanoes have had an even more dramatic effect. The 1783 Lakagígar eruption in Iceland spewed enough material into the atmosphere to result in, among other things, the freezing of the Mississippi River at New Orleans and ice floes in the Gulf of Mexico.

There are far better reflective materials we can put in the atmosphere than the random emissions of volcanoes. Current thinking holds that sulfate aerosols are the best bet. The mechanics of how to get sufficient materials up there have been worked out, and the cost is astonishingly small. Something on the order of $8 billion a year may suffice.

Jeff Bezos could do this by himself. So could any number of individual countries, without missing a beat. So what’s holding us back? Quite a few things, aside from general inertia.

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. 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 and do 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 on the planet. 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. In December 
Harvard announced that a team will do just that on a very small scale, launching the Stratospheric Controlled Perturbation 
Experiment in 2019.

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 stop spending tens of trillions of dollars 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 three years’ time after the president said: “Go.” NASA put humans on the moon in eight. 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.