The promises and perils of geoengineering

Geoengineering signifies things that humans do intentionally to make a large-scale difference in the climate.

Our book discusses two categories of geoengineering. The first, carbon dioxide removal, consists of a variety of techniques to remove carbon from the atmosphere and store it for long periods of time. Techniques range from planting a forest to implementing industrial technologies for carbon capture and underground storage.

The other main family of geoengineering approaches is solar geoengineering, or solar radiation management. This refers to techniques that would block a small fraction of incoming sunlight, which would have a cooling effect on the Earth. Stratospheric aerosol injections, which put tiny particles into the upper atmosphere, are one such method. Cloud brightening, which could involve spraying salt into the air from ships to make reflective marine clouds, also has potential.

I’m certainly hoping that the world can ramp up climate action and avoid solar geoengineering. But I do think that we should be pursuing carbon removal in earnest, which is something the authors in this book are divided on. I think there are both promising and perilous implementations of carbon removal, and that environmentalists should be involved in shaping the choices here.

On the carbon removal side, there’s a lot of momentum and interest, especially this year, because so many companies, cities and nation states are moving forward with these net zero goals. Net zero targets generally imply some form of carbon removal to balance the amount of continued emissions. There are many types of projects underway in that realm, from programs to pay farmers for storing more carbon in soils to monthly subscriptions you can get for services that remove your emissions directly from the atmosphere.

With regard to solar geoengineering, it’s entirely in the research stage. Research has been funded for marine cloud brightening in relation to the Great Barrier Reef to see if there are applications for lessening harm to coral. But there isn’t any open-air research on stratospheric aerosol injections. There’s been one experiment proposed by researchers at Harvard University, but that keeps getting delayed. That one would be a relatively small experiment involving a stratospheric balloon and a few kilograms of material.

Carbon removal at the scales that are being discussed would involve a vast infrastructure program. You have to imagine things like massive land-use changes for growing forests to sequester more carbon, or the construction of injection wells for carbon dioxide (CO2). These policies are going to affect communities.

One key concern that I think a lot of authors in this book have is that carbon removal will be seen as a way out for polluters, a solution that legitimizes a cleaner version of fossil fuel production. They are understandably concerned about developing technologies to remove CO2 because that could imply continued production of it.

Another concern people might have is the cost of developing these technologies, which isn’t something that’s discussed very much in this book. What’s the cost going to be, and who’s going to bear it?

Solar geoengineering raises some similar concerns about mitigation deterrence, but magnified. If solar geoengineering begins, would we be caught in a trap where we’re continually blocking sunlight and continuing to emit fossil fuels?

But beyond that, solar geoengineering faces an enormous challenge relating to how it might be governed, since it’s a planetary-scale intervention. The politics are very complicated. Carbon removal is something that can be implemented all around the world in different ways, but solar geoengineering is something that you’d want a global consensus on. I could very easily see a situation where a couple of countries agree to do it, and nobody disagrees with them, which is different from a global consensus.

Solar geoengineering could also have many unintended consequences. Projected precipitation impacts have been studied in models. Something that I don’t think has been studied as much are impacts on ecosystems from changes in incoming sunlight. To me, that seems less well understood. I think we need public funding for geoengineering research that can systematically look for side effects and unintended consequences.

A lot of the authors in this book would disagree, and the good thing about an edited collection like this is that you can have a lot of different perspectives. People who are critical of funding this research say that we shouldn’t expend energy studying this. Once you start funding research, you create vested interests that want to continue their research.

There are a few reasons. One is a normative one — that people should be involved in the design of these technologies.

Geoengineering projects will touch billions of lives in one way or another. A lot of the social science on geoengineering is about, Will people accept this? The contributors in this book are trying to push the social questions a bit further: Where is this idea even coming from? Why are we at this point? Who needs to be involved in making decisions?

As just one example, we were fantastically lucky to have Kyle Whyte, who has a lot of great writing on climate justice, speak to us about what participation might mean for Indigenous peoples in the context of geoengineering. In an interview published in the book, one of the key points that he makes is that it’s not reasonable to expect Indigenous people to participate in discussions that don’t allow Indigenous people to bring their concerns to the table. If the conversation is already pre-framed in terms of what’s important to discuss, there aren’t a lot of opportunities for meaningful engagement.

This book is aimed at specialists who are interested in social science and the politics of geoengineering. Climate advocates and critical theorists working on the intersection of climate change and social science, especially those thinking about justice, capitalism or imperialism, may find something of interest here.