End of The Line: The Innovation, Politics, and Governance of Climate Engineering

Abstract

Reducing greenhouse gas emissions isn't enough. Staring down the barrel of climate catastrophe, we are exploring new technological solutions to our climate quagmire.

Greenhouse gas removal (GGR) is needed to limit global warming to under 1.5C or 2C, thus meeting the goals of the 2015 Paris Agreement. However, GGR at the scale necessary is difficult and will likely take some time. Solar geoengineering, reflecting sunlight to quickly cool the Earth, can buy time and in the meantime help avoid the catastrophic risks of global warming. This thesis focuses on the most widely impactful and discussed reflection method - stratospheric aerosol injection (SAI).

However, foundational questions of their plausibility and desirability are unanswered. If removal and reflection prove implausible or undesirable, it may be time to acknowledge that we have reached the eEnd of the lLine - that we have exhausted our options to effectively limit global warming and thus face climate catastrophe. This thesis is an interdisciplinary investigation of the plausibility and desirability of GGR and SAI.

GGR requires the rapid innovation and scale up of many technologies. However, the empirical evidence of large scale systemic technological change indicates a century-long timeline. Additionally, GGR requires large changes in supporting systems that will likely add delay. GGR also requires the development of multiple approaches and 'dominant designs', limiting acceleration effects of economies of scale. Given GGR is likely to err slow, we may have to research SAI to buy time for renewable energy and removals.

SAI research is controversial due to concerns that research is a first step on a 'slippery slope' to deployment. However, there is no clear understanding of how a slippery slope could happen. This thesis puts forward a typology of slippery slopes, emphasising the importance of creating early lock-in to prevent unintended runaway feedback loops.

Slippery slope risks are important due to SAI's deployment risks. However, holistic risk assessments of SAI deployment are limited, and do not consider deeper aspects of risk like compound hazards or systemic risk. This thesis develops a framework for holistic risk assessment, applied to SAI. SAI's 'average' outcomes are likely safer than climate change. But under unlikely but highly impactful system cascades and interactions with other global catastrophes, SAI can harbour risks worse than climate change.

Given such extreme risks, we can try develop policy that accelerates GGR as best as currently possible. This thesis focuses on Australian GGR policy, advancing four leverage points of a successful Australian GGR policy strategy: creating a government home for systemic coordination, leveraging cooperative and competitive federalism, ensuring trust in sequestration and offset mechanisms, and sparking innovation. But even with full implementation, these may not result in sufficiently quick GGR.

Interestingly, across history are rapid, large, and complex technological changes that broke the speed limit, like the Apollo Program or COVID-19 vaccines. These were the result of deliberate political forcing. Breaking the GGR speed limit is possible, but like any centralised forcing, will come at a severe and deeply unequal social cost. Whether this is worse than the risks of climate change or SAI is uncertain. Such risk discussions are unfortunately missing from extant GGR literature.

We are thus not at the end of the line. Limiting global warming, without resorting to risky SAI, requires forcing rapid GGR innovation and deployment. There is a narrow corridor to 1.5C. Whether we should take it is another matter. Show more