The Climate Fix Book Club, Chapter 5

Technological Fixes and Backstops

Chapters 1-4 of The Climate Fix covered climate science and the challenges of decarbonizing the global economy. In Chapter 5, things start getting really fun — I discuss geoengineering and carbon capture. I really like this chapter because it is as current in 2023 as it was when I wrote it.

The Climate Fix, Chapter 5, Technological Fixes and Backstops

The discussion so far suggests that policies now being contemplated by governments around the world to decarbonize their economies in coming years and decades are almost certainly going to fall far short of their goals. What happens if it turns out that despite the best intentions and effort, concentrations of carbon dioxide continue to increase to levels that policy makers and the public deem to be unacceptable? Recent discussions of climate policies have increasingly emphasized “geoengineering” of the global Earth system.

In January 2009 The Independent, a newspaper in the United Kingdom, asked eighty climate experts if the dismal performance of mitigation policies meant that a “Plan B” was now needed. The “Plan B” referred to by The Independent was “research, development and possible implementation of a worldwide geoengineering strategy.” More than half responded in the affirmative.

Geoengineering has come to mean a range of different things, and pinning down a definition is an important first step to deciding whether it’s something we ought to pursue. In 2009 the American Meteorological Society defined geoengineering as

“deliberately manipulating physical, chemical, or biological aspects of the Earth system” with a focus “on large-scale efforts to geoengineer the climate system to counteract the consequences of increasing greenhouse gas emissions.”

The AMS recognized that geoengineering overlaps with policies focused on both adaptation and mitigation:

“To the extent that a geoengineering approach improves society’s capacity to cope with changes in the climate system, it could reasonably be considered adaptation. Similarly, geological carbon sequestration is considered by many to be mitigation even though it requires manipulation of the Earth system.”

Efforts to use social and economic policies to modulate concentrations of greenhouse gases might also be considered a form of “geoengineering,” albeit differentiated from other attempts to manipulate the Earth system in the means employed: social policies rather than technological ones. Nevertheless, the focus in this chapter is on technological approaches to deliberately manipulating the Earth system in order to cope with or remediate accumulating carbon dioxide in the atmosphere.

A wide range of different geoengineering technologies are commonly discussed in the climate debate. Perhaps the most frequently discussed approach is the injection of particles, or aerosols, into the stratosphere in order to reflect sunlight away from Earth, creating a cooling effect. The mechanism behind this proposal mimics what has been observed when a powerful volcano erupts, sending ash high into the atmosphere, such as when Mount Pinatubo erupted massively in the Philippines in 1991. The resulting effect is a temporary cooling of Earth due to the fact that the particles high up in the atmosphere reflect sunlight back into space, serving as a sort of sunshade. The effect is temporary, as the particles settle out of the atmosphere. Any effort to artificially inject particles into the stratosphere would thus have to continuously replenish the aerosols.

Stratospheric injection of aerosols was popularized by Steven Leavitt and Stephen Dubner in their book Superfreakonomics. They wrote about a science fiction–like proposal to inject particles into the stratosphere via a giant hose tethered to a balloon, blocking sunlight a bit and cooling the earth. They proposed that such a technology could be implemented relatively inexpensively, compared to efforts to reshape the global economy in a less carbon-intensive manner. The discussion prompted a vigorous and at times acrimonious debate over geoengineering and its role in the climate debate.

Other widely discussed approaches include seeding the oceans with iron in an effort to increase the absorption of carbon dioxide into the oceans through biological processes. Such proposals have been controversial because of their unknown effects on ocean ecosystems. In 2009 a group of German and Indian scientists dumped six tones of iron into the ocean near Antarctica and evaluated its effects on taking up carbon dioxide. The results were unexpectedly modest, and the experiment generated a range of opposition. Another geoengineering proposal involves the large-scale creation of clouds in marine environments, sometimes called marine-cloud brightening or whitening, in order to increase the amount of sunlight reflected back into space, and thereby cool our planet.

This chapter focuses on several different geoengineering proposals that are distinguished into two broad categories. The first category includes those technologies that seek to counteract or offset the effects of increasing greenhouse gases, such as by injecting aerosols into the stratosphere. I argue that such efforts to manage the climate system are fraught with so much uncertainty and ignorance that unintended consequences are inevitable. Such efforts to “play God” in the Earth system would be confronted with technical, political, and social obstacles, making climate management a fairly undesirable approach to dealing with accumulating carbon dioxide in the atmosphere. The second category involves efforts to remove carbon dioxide from the atmosphere and to store it somewhere, which I call carbon remediation. Such technologies are unproven and expensive, and some are fanciful. However, with respect to practicality and political expediency the capture and sequestration of carbon dioxide is far preferable than those technologies that seek to deal with the consequences of increasing concentrations of carbon dioxide. While it is true that technology will be at the core of any successful effort to deal with accumulating carbon dioxide in the atmosphere, with geoengineering as with more conventional approaches to mitigation, there is (unfortunately) no quick and easy technological fix.

The full text of Chapter 5 can be found below of THB Pro subscribers. You can also find PDFs of Chapters 1-4 (and a bunch of other good stuff) here. I welcome your comments, questions and discussion. Thanks for your support!