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Today more than ever, it is critical that society has a conversation on geoengineering. We need to discuss if and how we want to research, develop, and/or deploy certain geoengineering techniques. However, a major obstacle is currently blocking the path towards effective conversation on geoengineering, namely that we cannot agree on what geoengineering actually is. In particular, the academic definition of geoengineering is quite different than the popular conception of the term. Unless this disconnect is addressed swiftly, the conversation on geoengineering is likely to stay muddled, and we are unlikely to reach agreement on the appropriate policy and regulatory path forward for a wide range of potential climate solutions.
Academic geoengineering: climate “remediation”
According to the IPCC: “Two categories of geoengineering are generally distinguished. Removal of GHGs, in particular carbon dioxide termed ‘carbon dioxide removal’ or CDR, would reduce atmospheric GHG concentrations… ‘Solar radiation management’ or SRM technologies aim to increase the reflection of sunlight to cool the planet.”
The salient feature of this definition is remediation: any strategy that is “intentionally designed to counteract the climate effects of past greenhouse gas emissions to the atmosphere” (emphasis mine, source: Bipartisan Policy Center) falls under the academic definition of geoengineering. The risks, costs, and/or uncertainties surrounding those solutions are not salient features of this definition, which is important because those characteristics do feature prominently in the popular conception of geoengineering.
The popular conception of geoengineering: high-danger, high-risk, low-cost techno-fixes
From my experience talking with many non-academic climate practitioners about what they mean by geoengineering, I have found that only a small subset of the climate remediation solutions are viewed as examples of geoengineering in the mainstream conversation about climate change. The solutions I hear cited as geoengineering in non-academic circles include stratospheric aerosol injection, ocean iron fertilization, and even space mirrors. The salient features of the popular conception of geoengineering include:
The core of this disconnect is that the academic definition of geoengineering blurs the line between geoengineering and mitigation. The IPCC notes that “the boundary between some mitigation and some CDR methods is not always clear,” and “some techniques that fall within the definition of CDR are also regarded as mitigation measures such as afforestation and BECCS.” All climate remediation solutions get included under the academic definition of geoengineering, whereas only some climate remediation solutions are seen as geoengineering among non-academic practitioners. For example, the academic definition of geoengineering includes many CDR approaches—like landscape restoration, soil carbon farming, and bioenergy with carbon capture and storage (BECCS)—that are seen exclusively as options for climate change mitigation in the mainstream climate conversation.
The mismatch between the academic and popular conception of geoengineering can muddle the conversation on whether/how we should be pursuing geoengineering solutions to climate change. If academics and non-academics think geoengineering is two different things, productive conversation about appropriate policy and regulatory pathways for the various climate solutions that potentially fall under the geoengineering umbrella is unlikely to emerge.
The academic community has proposed a number of ways to address the confusion caused by the current academic definition of geoengineering. The National Academies and other academics like Joshua Horton have suggested that the definition of geoengineering be split into two separate conversations: one about CDR, the other about SRM. But academics like Duncan McLaren have noted that some CDR solutions—in particular ocean iron fertilization—fit the non-academic conception of geoengineering very well. This definition would simply shift the disconnect between the academic and popular conception of geoengineering from one of Type I errors to one of Type II errors.
Some academics like Clare Heyward have proposed that we stop using the term geoengineering altogether, and instead address more specific groups of climate solutions individually. I like this idea the best, but the geoengineering cat is out of the bag, and it will likely be incredibly difficult to get the mainstream conversation to stop using the term as well.
An alternative path forward
Given that the geoengineering term is likely here to stay in mainstream climate conversation, an alternative way forward would be for the academic community to start defining geoengineering in a way more closely aligned with the popular conception of the term. Instead of defining geoengineering as the catchall “climate remediation,” the academic community could redefine geoengineering to be based on the risk, uncertainty, and cost profile of a given climate solution.
This approach has the key benefit of letting us have separate conversations about whether we should be doing climate remediation and whether we should be doing geoengineering. With this definition, we can discuss whether we should pursue climate remediation (e.g. landscape restoration, soil carbon sequestration, etc.) without deploying geoengineering solutions (e.g. ocean iron fertilization). In effect, a “yes, climate remediation; no, geoengineering strategy” is what we argue for at the Center for Carbon Removal. But explaining this strategy in these commonly understood terms will remain challenging until the academic definition of geoengineering converges with the popular conception.
This post is part of a series.
Noah Deich is Executive Director and Founder of the The Center for Carbon Removal, an initiative of the Berkeley Energy and Climate Institute at the University of California, Berkeley. He has experience in management consulting, where he worked on clean energy and corporate sustainability projects. Noah has also conducted carbon removal business analyses for investment firms across the globe. He received his M.B.A from UC Berkeley in 2015, and his B.A. from the University of Virginia in 2008.
The Forum for Climate Engineering Assessment does not necessarily endorse the ideas contained in this or any other guest post. Our aim is to provide a space for the expression of a range of perspectives on climate engineering.