David Warsh: Looking at a ‘three-pronged approach’ to global warming

Average surface air temperatures from 2011 to 2020 compared to the 1951-1980 average

SOMERVILLE, Mass.

The most memorable theater scene I’ve ever witnessed was performed one summer evening long ago in a courtyard at the University of Chicago. The play was Luigi Pirandello’s Six Characters in Search of an Author, a complicated work from the 1920s about the relationship between authors, the stories they tell, and the audiences they seek.

At one point, a company of actors, having been interrupted in their rehearsal by a family of six seeking a playwright to tell their story, are bickering furiously with their interrupters when, at the opposite end of courtyard, two key members of the family had slipped away, to be suddenly illuminated by a spotlight as they stood beneath a tree to make a telling point: their story was as important as the play – maybe more. The act ended and the lights came up for intermission.

That was the technique known as up-staging with a vengeance, an abrupt diversion of attention from one focal point to another.

I remembered the experience after reading Three Prongs for Prudent Climate Policy, by Joseph Aldy and Richard Zeckhauser, both of the Harvard Kennedy School, a sharply critical appraisal of the prevailing consensus on the prospects for controlling climate change. Delivered originally as Zeckhauser’s keynote address to the Southern Economic Association in 2019, you can read it here for free at Resources for the Future.  Its thirty pages are not easy reading, but they are formidably clear-headed, and I doubt that you can find a better roundup of the situation that the leaders are discussing blah-blah-blah next month at the U.N.’s Climate Change Conference in Glasgow.

The possibility of greenhouse warming was broached 125 years ago by the Swedish physical chemist Svante Arrhenius. The specific effect was discovered by Roger Revelle in 1957, and the growing problem brought into sharp focus in the U.S. by climate scientist James Hansen in Senate testimony in 1988.  It has taken thirty years to reach a broad global consensus about the first of Aldy and Zeckhauser’s three prongs.

“For three decades, advocates for climate change policy have simultaneously emphasized the urgency of taking ambitious actions to mitigate greenhouse gas (GHG) emissions and provided false reassurances of the feasibility of doing so. The policy prescription has relied almost exclusively on a single approach: reduce emissions of carbon dioxide (CO₂) and other GHGs. Since 1990, global CO₂ emissions have increased 60 percent, atmospheric CO₂ concentrations have raced past 400 parts per million, and temperatures increased at an accelerating rate. The one-prong strategy has not worked.’’

A second prong, adaptation, has been added in to most menus in recent years: everything from design changes (moving electric installations to roofs instead of basements) to seawalls, marsh expansions, and resettlement of populations. Adaptations are expensive.  A six-mile long sea barrier with storm surge gates might protect New York City from climate change, but would take 25 years to build.

A third prong of climate policy ordinarily receives little attention. This is amelioration, or “the ‘G’-word,” as the chair of British Royal Society report dubbed it in 2009, meaning the broad topic of geo-engineering. For a dozen years, it was thought possible that fertilizing the southern oceans might grow more plankton, absorb more atmospheric carbon, and feed more fish. Experiments were not encouraging.   The technique considered most promising today is solar-radiation management, meaning creating atmospheric sun-screens for the planet.  The third prong is by far the last expensive of the three.  It is also the most alarming.

Ever since “the year without a summer” of 1816, it has been known that volcanic eruptions, spewing sulfur particles into the atmosphere, produce worldwide net cooling effects. Climate scientists now believe that airplanes could achieve the same effect by spraying chemical aerosols  at high altitudes into the atmosphere.  The trouble is that very little is known with any certainty about the feasibility of such measures, much less their ecological effects on life below.

Many environmentalists fear that the very act of public discussion of solar- radiation management will further bad behavior – create “moral hazard” in the language of economists. Glib talk by enthusiasts of economic growth about cheap and easy redress of climate problems will diminish the imperative to reduce emissions of greenhouse governance, some say. Others think that sulfur in the air above would accelerate acidification in the oceans below. Still others doubt that global governance could be achieved, since such measures would not offset climate change equally in all regions, Rogue nations might undertake projects that they hoped would have purely local effects.

Aldy and Zeckhauser argue that bad behavior may in fact be flowing in the opposite direction.  Climate change is an emotional issue; circumspection with respect to solar-radiation management is the usual stance; opposition to research is often fierce. As a result, very little has been performed. One of the first outdoor experiments – a dry run – was shut down earlier this year.

In his 2018 Nobel lecture, William Nordhaus, of Yale University, saw the problem somewhat differently.

“To me, geo-engineering resembles what doctors call ‘salvage therapy’– a potentially dangerous treatment to be used when all else fails. Doctors prescribe salvage therapy for people who are very ill and when less dangerous treatments are not available. No responsible doctor would prescribe salvage therapy for a patient who has just been diagnosed with the early stage of a treatable illness. Similarly, no responsible country should undertake geo-engineering as the first line of defense against global warming.’’

After a while, it seemed to me that the debate over global warming does indeed bear more than a little resemblance to what goes on in Pirandello’s play. Three possible policy avenues exist. The first is talked about constantly: the second enters the conversation more frequently than before. The third is all but excluded from mainstream discussion.

It’s not so much about what stage of a treatable illness you think we’re in.  Public opinion around the world will determine that, as time goes by. It’s about whether the question of desperate measures should be systematically explored at all.  The three-pronged approach is a policy in search of an author.

David Warsh, a veteran columnist and an economic historian, is proprietor of Somerville-based economicprincipals.com, where this essay first appeared.