Geoengineering. Gernot Wagner

and me around 2016, when we were in the early stages of developing what would turn into Harvard’s Solar Geoengineering Research Program. (More on that later, too, primarily in Chapter 3.) Wake introduced himself as having held, among many other accomplishments, the position of former President and Chairman of Pemco World Air Services, a leading airplane modification company. He clearly had a lot of expertise on the subject, he cared about climate change, and he wanted to try to be helpful. We met.

      I began our first meeting in the way I tended to whenever I spoke to anyone with any kind of business or finance background: Ours was a research effort; commercial interest would be dangerous. And in any case, there was no commercial case here: “Have you heard of the free-driver effect?” Wake assured me he had no financial interest, but that he was, in fact, curious about the free-driver effect. He had read David Keith’s book and about how modified business jets could work. From David, verbatim:

      Injection of sulfates might be accomplished using Gulfstream business jets retrofitted with off-the-shelf low-bypass jet engines to allow them to fly at altitudes over sixty thousand feet along with the hardware required to generate and disperse the sulfuric acid.¹¹

      Wake was skeptical. He didn’t want to say so directly, at our first meeting, but he clearly thought such a retrofit wouldn’t work. Or rather, that a more powerful engine implied a new plane, a new certification process, the works. For someone who used to run a company modifying planes, this seemed like a different exercise altogether: designing a new plane.

Wake set out to demonstrate that his initial reaction was correct. He spoke to engineers at Airbus, Atlas Air, Boeing, Bombardier, GE Engines, Gulfstream, Lockheed Martin, NASA, Near Space Corporation, Northrop Grumman, Rolls Royce Engines, Scaled Composites, The Spaceship Company, and Virgin Orbit.¹² He did what someone with a deep business background would do: he created a development plan for how one might approach a venture that could design such a plane, finance the development, and see things through from conceptualization to deployment.

      We ended up co-authoring a paper describing the process, laying out “Stratospheric aerosol injection tactics and costs in the first 15 years of deployment.”¹³ The gist was: Existing planes are inadequate. It would take a newly designed plane with a large fuselage and sizable wingspan to transport the material and fly into the lower stratosphere. Moving such a plane from concept to deployment would take the better part of a decade.

      None of that is free. It would cost billions. But nobody we spoke to had any doubts that it would be possible to do. And the cost figures confirmed the broader sentiment: single-digit billions of dollars per year are, in fact, cheap. Very cheap.

      The direct comparison with cutting CO₂ emissions is a problem for many reasons. Timescales is one. While solar geoengineering could lower global average temperatures within months, addressing the root cause by cutting CO₂ emissions and pollution would show effects only over decades and centuries. But it is clear that, while far from free, solar geoengineering is indeed very cheap by comparison. The absolute lowest estimates of decarbonizing the world economy come in at around $50–100 trillion.¹⁴ That’s the total estimate, not the annual cost, but it is still at least 100 to 1,000 times more expensive than the cost estimates for solar geoengineering. If anything then, solar geoengineering is too cheap.

In a rational world, there would be no such thing as too cheap. Even if something were indeed free, we would not have to do it if we did not want to. Of course, we don’t live in a rational world. To begin with, it’s highly unclear who the “we” here is. Who makes the decision? Who might be motivated to pay for such a venture? Equally important: If solar geoengineering is so cheap, and the free driver is so dominant, why isn’t it happening already?

      Sand in the free driver’s gears

      The fact that even a full-scale deployment of stratospheric aerosols seems incredibly cheap goes hand-in-hand with some incredible economics.¹⁵ “Not if, but when” is the logical conclusion. But there’s one more step worth discussing. If it is indeed so cheap and easy, why hasn’t it happened already?

      That’s akin to the joke about two Chicago economists walking down the street and spotting a $20 bill on the ground. Turns one to the other: “Hey, why aren’t you picking it up?” Says the other: “It can’t be real. If it were, somebody else would have picked it up already.”

      Of course, there are plenty of reasons why markets aren’t – can’t be – as efficient as the simplistic, stereotypical “Chicago-style” economics model might suggest. If they were, there wouldn’t be a need for the very business schools that are the academic homes of many of these economists. Nor would there be a need for the management consultancies staffed by graduates of said schools. The Swedes these days are handing out Nobel Prizes to “behavioral” economists for good reason. I put “behavioral” in quotes because, in the end, it’s just good economics. Making demonstrably false assumptions of perfect “rationality” isn’t. Still, it is worth investigating why solar geoengineering hasn’t yet been deployed, especially since it is so cheap.

In short, there seems to be plenty of sand in the free driver’s gears. The list of possible explanations is long and often very rational. One such explanation is that politicians might fear opposition from deep greens, environmentalists vehemently opposed to the technology. A slightly different flavor of this argument is that pro-solar geoengineering politicians might first want to signal to environmentalists that they are committed to decarbonization. Or, to up the rationality ante even further, politicians might want to pursue solar geoengineering, but they fear that it cannot be effectively governed at the international level – always a good assumption – and, hence, shy away.

      All of these explanations are consistent with the apparent conundrum of too little action. They have all appeared in peer-reviewed solar geoengineering literature, my own academic writings included.¹⁶ They might all just be one too rational. It’s not as though the free-driver hypothesis states that solar geoengineering happens instantaneously and automatically. That’s taking the “rational” Chicago-style explanation quite a bit too literally.

      No, Mikhail Budyko, when introducing the idea of stratospheric aerosol injection in 1974, should not have led to it right then and there, nor should have the English translation of his book in 1977.¹⁷ Paul Crutzen and Ralph Cicerone might have lifted the self-imposed moratorium among researchers in 2006, leading to an exponential increase in research interest and publications but, over a decade later, direct global research funding on the topic is still at most around $20 million per year.¹⁸ That compares to the U.S. government alone spending over $2 billion on overall climate science research.¹⁹ It is still early days in solar geoengineering research. Uncertainties abound.

      It’s similarly clear that it would take many years, perhaps decades, to see anything close to a comprehensive deployment program in action – even when somebody somewhere decides to pull the trigger.

Who decides?

      That immediately leads to the biggest question of them all: who would that “somebody” be?

      It’s tempting to look to national governments to be in the driver’s seat. It is they, after all, who are, or at least should be, in the lead on climate policy in the first place. We have already established that dozens would have the financial means to pursue a largescale solar geoengineering deployment program.²⁰ It is governments who ought to balance solar geoengineering with other urgent domestic priorities, primarily cutting CO₂ emissions. It is also they who ought to coordinate solar geoengineering at the international level. That goes for any multilateral, United Nations-led efforts. That also goes for bilateral talks in any number of constellations. NGOs, businesses, and other private actors matter, some more than others. Ultimately, though, it is governments who set policy.

      What if solar geoengineering is not set by governments? For one,