SRMs fail. Be skeptical of their scholarship — it’s designed to maintain existing power structures.

Solar geoengineering research is being conducted primarily by scientists in the Global North, although some research is occurring in other parts of the world (Biermann & Möller, Reference Biermann and Möller2019). The leading effort in terms of funding, scientific research, governance development and experimental preparation is Harvard's HSGRP. The expansive influence of the HSGRP represents the power imbalances in solar geoengineering research. The HSGRP is largely composed of white men at an elite institution advocating research into planetary-scale climate manipulation on behalf of the poor in the Global South (Horton & Keith, Reference Horton, Keith and Preston2016). This well-meaning approach does not appear to recognize the structural power imbalances invoked in this stance or the colonial legacies of paternalistic, technocratic humanitarianism flowing from the Global North to the Global South (Escobar, Reference Escobar2011; McCarthy, Reference McCarthy2009; Mitchell, Reference Mitchell2002). Privileged scientists are justifying their research by making claims that they might be able to fix injustices for the global poor in a way that does nothing to address the root causes of either climate vulnerability or global inequality, amounting to a form of ‘expert imperialism’ (see Flegal & Gupta, Reference Flegal and Gupta2018; Hourdequin, Reference Hourdequin2018; McLaren, Reference McLaren2018; Surprise, Reference Surprise2019).

That solar geoengineering has the potential to reduce climate vulnerability without addressing the structural injustices of global power and inequities makes it an attractive ‘philanthropic’ venture for billionaires and other wealthy elites concerned with climate change. Major funders of solar geoengineering research include, for example, Bill Gates, whose Fund for Innovative Climate and Energy Research (FICER) authorizes Harvard University Professor David Keith and Ken Caldeira (of the Carnegie Institution for Science) to distribute millions of dollars to solar geoengineering researchers (FICER, 2019). In addition to Gates, Harvard's research programme is supported by an array of other technology billionaires, hedge fund managers and boutique foundations that serve as philanthropic arms of wealthy individuals (Surprise, Reference Surprise2019). For example, the Open Philanthropy Project, founded by Cari Tuna, billionaire Dustin Moskovitz (a co-founder of Facebook) and Holden Karnofsky (formerly of hedge fund Bridgewater Associates), is another major supporter of SAI research at Harvard and around the world. Although some of these billionaire philanthropists invest in a range of climate change initiatives, solar geoengineering plays a specific role in their climate investment portfolios. Given its capacity to slow the rate of change and reduce the urgency of decarbonization, SAI enables wealthy, corporate-connected philanthropists to support moderate climate policies rather than more transformative, systemic changes that would directly threaten their own concentrations of wealth and power.

In addition to the solar geoengineering research occurring in the USA and Europe, the Solar Radiation Management Governance Initiative (SRMGI) has launched the DECIMALS Project, a strategic initiative to provide funding to encourage geoengineering research at Global South institutions. Although this project diversifies and broadens who is involved in solar geoengineering research, it is funded by the same philanthropies that fund research in the Global North (e.g., Open Philanthropy Project, FICER and other billionaire-connected philanthropies such as Zennström and Carbon War Room; see Necheles et al., Reference Necheles, Burns, Chang and Keith2018). Expanding the global distribution of SAI researchers does not address the structural power imbalances associated with who is advancing solar geoengineering research. In addition, it is well recognized that creating mechanisms for the inclusive ‘participation’ of Global South organizations in transnational policy networks has often been used as a vehicle to generate consent for policy prescriptions that flow from the Global North (Banerjee, Reference Banerjee2003; Goldman, Reference Goldman2007; Peet, Reference Peet2002; see Frumhoff & Stephens, Reference Frumhoff and Stephens2018, on participation in geoengineering).

4. Among those advocating for geoengineering research, how are they conceptualizing social justice and social change?

Given the power and influence of who is currently conducting and funding solar geoengineering research, it is important to consider how they are conceptualizing social justice and social change. What kinds of futures do these researchers envision in their models and scenarios? Solar geoengineering is often considered a mechanism to reduce climate vulnerabilities while ‘buying time’ for mitigation measures to scale up and energy transformations to occur (Surprise, Reference Surprise2018). If a potentially dangerous, planetary-scale intervention is being advocated to ‘buy time’ for other solutions, it is important to consider how solar geoengineering researchers envision current global injustices and future social change, including the potential for political and economic shifts. Although the research community is not uniform, few solar geoengineering researchers appear to be advocating strongly for urgent and transformative climate policy. Several influential researchers in the field have expressed alignment with moderate approaches centred on a mix of incremental market mechanisms, policy prescriptions and technological innovations (e.g., Horton et al., Reference Horton, Keith and Honegger2016; Keith, Reference Keith2013; Wagner & Weitzman, Reference Wagner and Weitzman2015). Moderation and incrementalism keep the core structures of political and economic power in place.

Indeed, solar geoengineering may appeal to many wealthy climate philanthropists explicitly because it offers an alternative to the growing recognition that responding to climate change will require transformative measures that directly challenge free-market capitalism (Foster et al., Reference Foster, Clark and York2011; Klein, Reference Klein2014; Wainwright & Mann, Reference Wainwright and Mann2018). The idea that confronting climate change demands a rapid, just and fundamental transformation away from our current fossil fuel-dominated capitalist political economies that are concentrating wealth and power seems to be untenable to many wealthy individuals, corporations and elite technocratic managers that profit from current systems that perpetuate inequities (Kenner, Reference Kenner2019; Lynch et al., Reference Lynch, Long, Stretesky and Barrett2019). For those that feel threatened by the call for radical, social, political and economic change, technological solutions, market mechanisms and moderate policies are appealing, even though they are inadequate responses to the scale of the emergent climate crisis (Huber, Reference Huber2019). By investing in extreme technical solutions to climate change, those advocating for solar geoengineering research are avoiding extreme (and necessary) social changes that are rapidly gaining political traction.

As to the ‘humanitarian’ social justice rationale, we have already questioned the ethical implications of a small group of privileged researchers from wealthy and powerful institutions propagating dangerous techno-fixes in the name of the global poor. Another problematic aspect of this relates to who gets to declare when the climate crisis is bad enough to justify SAI deployment. Climate change is already causing extreme suffering for millions of people around the world, but most solar geoengineering researchers are not yet advocating for deployment. Most solar geoengineering models do not anticipate deployment in the next decade, so those advocating for solar geoengineering research seem to be more concerned about future rather than current climate impacts and climate injustices. Emergencies are not merely objective circumstances – they are determined by political calculations and power dynamics (Agamben, Reference Agamben2005; Schmitt, Reference Schmitt2005; Sillmann et al., Reference Sillmann, Lenton, Levermann, Ott, Hulme, Benduhn and Horton2015). Who will decide when conditions are bad enough to declare a planetary-scale emergency justifying intervention in the climate system? It is unlikely to be poor countries, vulnerable populations or the hundreds of millions – if not billions – of people already living in ‘emergency’ conditions of poverty and climate vulnerability (Ehrenreich, Reference Ehrenreich2019; Tahir, Reference Tahir2019). Solar geoengineering research diverts attention and funding away from immediate systemic changes that could meaningfully address current inequalities and injustices.

The primary political effect of advancing solar geoengineering research is, therefore, to blunt the urgent, transformative proposals emanating from the climate justice movement. In so doing, solar geoengineering research – independent of the desires of individual researchers – maintains contemporary systems of power, which we define as systems of colonial capitalism that thrive on fossil fuels and the perpetuation of inequality, exploitation and domination buttressed by patriarchal white supremacy (Faber et al., Reference Faber, Stephens, Wallis, Gottlieb, Levenstein and CoatarPeter2017; Federici, Reference Federici2004; Pulido, Reference Pulido2016; Watts, Reference Watts2006; Whyte, Reference Whyte, Adamson and Davis2016).

5. How and by whom is solar geoengineering likely to be deployed?

An additional set of hidden injustices are revealed when we explore how and by whom solar geoengineering technology is likely to be deployed. These questions have been central to recent geoengineering social science research and governance debates, with a focus on the potential for inappropriate unilateral deployment by a powerful state or group of states, a corporation or even a wealthy individual (Rabitz, Reference Rabitz2016; Victor et al., Reference Victor, Morgan, Apt and Steinbruner2009). The scope of unilateral deployment has been narrowed in recent literature, with consensus emerging that only a few major nation-states are likely to have both the technological capacity and political legitimacy to deploy SAI (Parker & Irvine, Reference Parker and Irvine2018; Parker et al., Reference Parker, Horton and Keith2018; Rabitz, Reference Rabitz2016; Smith & Wagner, Reference Smith and Wagner2018), and that, given this possibility, solar geoengineering deployment should ideally be coordinated through international institutions. Despite growing attention being given to governance challenges, the potential injustices associated with the likely militarization of solar geoengineering has received minimal consideration. For example, a recent authoritative survey of solar geoengineering governance provides minimal discussion of SAI and militaries, noting only that while military involvement should ideally be restricted, militaries have necessary technological and logistical expertise and so should not be shut out of research and development, and regardless, no practical mechanisms currently exist to prevent military involvement in research and potential deployment (Reynolds, Reference Reynolds2019a, p. 207).

Concern about the militarization of solar geoengineering is based on three core points: first, military and security institutions have been involved in advancing solar geoengineering research in recent years, from the Central Intelligence Agency funding the first National Academies reports (Liebelson & Mooney, Reference Liebelson and Mooney2013) to the Defense Advanced Research Projects Agency funding SAI research at the Pacific Northwest National Laboratory (Kravitz et al., Reference Kravitz, MacMartin, Mills, Richter, Tilmes, Lamarque and Vitt2017). Second, leading deployment scenarios explicitly integrate assumptions about militarization and rely on military discourse and the technological expertise of defence contractors. For example, Parker et al. (Reference Parker, Horton and Keith2018) explore the possibility of so-called ‘counter-geoengineering’ measures (i.e., deploying warming agents to counteract or neutralize an SAI programme) in the context of geopolitical brinksmanship and ‘grey-zone conflict’, and Smith and Wager (Reference Smith and Wagner2018) consult with major aerospace and defence corporations to inform their cost–technology analysis. Third, the assumption that solar geoengineering cannot be tactically deployed or weaponized avoids the potentially strategic role that solar geoengineering could play in the interlinkages among geopolitics, energy and climate change. For example, the US military – the most powerful military force in the world – both runs on and plays a fundamental role in securing the fossil fuels that undergird US geopolitical power (Belcher et al., Reference Belcher, Bigger, Neimark and Kennelly2019; Foster & Clark, Reference Foster and Clark2018; Jones, Reference Jones2012; Lehmann, Reference Lehmann2019).

Yet, the US military also considers climate change a threat to national security and global stability (Hagel, Reference Hagel2014; Roberts, Reference Roberts2018). It is therefore entirely possible that the US security establishment could expand its involvement in solar geoengineering development in order to achieve the dichotomous strategic objectives of managing the threat of climate change while simultaneously furthering the expansion of fossil fuels – even if temporarily (Surprise, Reference Surprise, Buck, Sapinksi and Malmforthcoming). International governance would likely have few tools to prevent this scenario if the USA deemed it in its strategic interest (Chomsky, Reference Chomsky2003; McCoy, Reference McCoy2017; Miéville, Reference Miéville2005). Given recent turns away from multilateral cooperation and the global rise of authoritarian leaders employing militarized violence to protect narrowly defined national interests while dismissing individual rights and social justice (Lutz, Reference Lutz2002; Robinson, Reference Robinson2018), the potential for militarized interventions into the climate system seems like too great a risk to continue advancing social geoengineering research.

6. Conclusion

Solar geoengineering is the ultimate ‘technological fix’ in that it aims to address the primary symptom of climate change (global warming) without addressing the root causes (Markusson et al., Reference Markusson, Dahl Gjefson, Stephens and Tyfield2017). The three questions we address here reveal dangerous, hidden injustices of advancing solar geoengineering research, where a few elite actors could gain the power to manipulate the Earth's climate. The exacerbation of global injustices perpetuated by solar geoengineering research should not be tolerated by anyone who is committed to advancing social justice in the world today. We believe that supporting solar geoengineering research is dangerous and unethical, and we call on governments, philanthropists and scientists to speak up about the risks of supporting this research.

Paying attention to who is supporting solar geoengineering research and how they envision social justice and social change is critically important to informing the public discourse and societal debate about how best to invest in confronting climate injustices (Stephens, Reference Stephensforthcoming). Advocates of solar geoengineering research seem to view the changing climate as a narrow, isolated, discrete problem. Rather than recognizing the social, economic and political complexities of how human systems interact with the climate, many scientists, engineers and others are engaging in a form of ‘climate isolationism’ (Stephens, Reference Stephensforthcoming). Yet climate science and social science tell us that transformative social change is desperately needed in order to ensure a just and liveable planet. Transformation requires challenging, not reinforcing, current power structures that have made it all too easy for billionaires and technocratic elites to focus on altering the climate system rather than altering our social and economic systems. Investing in solar geoengineering research not only detracts from efforts to accelerate transformation, but also creates new pathways for the rich and powerful to have additional control as climate impacts worsen. We believe this to be unjust.