Currently, the development of climate-engineering technologies, most notably solar radiation modification (SRM) programs and carbon dioxide removal (CDR) strategies, constitute one of the century’s most consequential geopolitical milestones. Considering how even standard mitigation policies cannot live up to the promises made in the Paris Agreement.

Only the United States and China possess the full resources to pursue unilateral climate engineering deployment.

Therefore, planet-scale interventions are being promoted as both a potential saviour and an existential danger at the same time. International governments are likely viewing the idea of planetary-scale approaches as a mixed blessing. As a consequence, the regulation of such technologies is at an impasse, beset by scientific indecision, geopolitical competition, and ethical turmoil over planetary management.

Global politics are likely to be reorganised around power asymmetries related to the large-scale impact of climate change. Although the number of states with the technical capability to apply stratospheric aerosol injections at the planetary level is estimated to be approximately 10, only those states that possess the full suite of economic, political, and military resources have the potential to surmount internal limitations and pursue unilateral deployment.

These are the United States and China. In any sense, this US-China duopoly establishes adequate limits on possible independent climate action by other technically competent states, and on parity of Sino-American alignment as a crucial criterion for determining whether, and how, the planet’s cooling might be initiated.

The growing effects of climate change increase the push for unilateral deployment. Their problem with geoengineering as a free driver, low direct expense, direct benefits provided to the initiating actor, and the distributed risks is highly suggestive of states pursuing it independently to face the climate emergencies. Adding to this dynamic is the relatively low level of international law currently limiting it, as it only provides limited deterrents, and there is no dedicated international governance in place.

The testimony of the Chinese national weather-control projects, and especially the massive one in the Tianhe region, shows the willingness of Beijing authorities to conduct ambitious atmospheric operations, the consequences of which are transboundary. At the same time, the United States has been considering the impact of geoengineering in its national security planning, with intelligence consultations noting the danger of unilateral application, which could create novel geopolitical hotspots. The meeting of capability and strategic interest is therefore a sign that climate engineering will be one of the instruments of great-power conflict, rather than one where parties operate together through cooperation.

The governance of climate engineering has the most implications in the systematic marginalisation of the voices of the Global South. Although developing nations are vastly underrepresented in terms of their vulnerability to climate effects and the unintended consequences of planetary action, they are also underrepresented in the development and governance deliberation processes.

Global South voices remain marginalized despite being most vulnerable to climate engineering risks.

The narrowness of research funding and technical capacity in the Global North results in what opponents refer to as the process of carbon colonialism, which involves profiting from the atmospheric commons to the benefit of wealthier countries through the sequestration of atmospheric carbon.

This segregation cannot be based solely on capacity limits. An example of the analysis of programs like The Degrees Initiative is how even so-called inclusive programs can perpetuate Northern hegemony under their agenda-setting and research agendas. Since these programs encourage Global South researchers to focus on solar radiation modification, they primarily concentrate on modelling implementation scenarios, rather than exploring governance options, thereby lending legitimacy to in-principle research positions. Northern-produced climate models regularly presuppose the local context and risks in vulnerable areas, creating a knowledge gap.

Other implications of this marginalisation are likely to extend beyond procedural fairness. The publics in the Global South demonstrate significantly stronger positive attitudes towards climate intervention technologies, while also expressing greater concern about the potential for exacerbating existing disparities. The paradox is a symptom of the desperate situations that climate-vulnerable nations now find themselves in, where even a flawed technological fix might seem preferable to unmitigated warming.

Their earnestness, however, is matched by a sharp understanding that unilateral deployment by global powers has the propensity to reallocate the environmental perils in such a manner that above-proportional dangers are targeted at those people groups and individuals who are most likely to be powerless.

The current global legal framework is insufficient to govern climate engineering technologies. The United Nations Framework Convention on Climate Change (UNFCCC), the Convention on Biological Diversity (CBD), and the Environmental Modification Convention (ENMOD) articulate pertinent principles.

However, none were specifically designed to address the distinct complexities inherent in planet-scale climate interventions. The preservationist nature of mitigation within the UNFCCC, which focuses on indirect actions rather than direct interventions, has conceptual conflicts with the paradigms of climate engineering. Similarly, the CBD has been successful in maintaining an unspoken moratorium on geoengineering, which, although welcome to hear, is neither feasible nor practically enforceable.

Current international legal frameworks are insufficient to govern planet-scale climate interventions.

Those governance failures are also reflected in the breakdown of negotiations at the 2024 UN Environment Assembly. The opposition of African states to any regulatory framework collided with the Swiss ideas of systemic expert supervision, forming a regulatory gap. Such paralysis highlights an even more overriding division in the international community: Does the use of climate engineering represent a last-ditch gambit, or is such an approach little more than unfortunate hubris that ends up shifting focus away from the vital necessity of emissions reduction?

When no specific multilateral institutions have been developed, non-state actors fill gaps in regulation. Weak oversight can allow uncoordinated experimentation, and an example of this can be seen in the actions of individuals like Make Sunsets, who have released unauthorised sulfur balloons into the atmosphere. The supporters of non-state governance argue that, at the very least, this mechanism can deliver nimble early oversight, and that its validity and performance beyond the proposal stage remain to be determined.

As an alleged aspect of potential adaptive reactions to anthropogenic climate change, climate engineering already functions as the most understudied locus of interstate conflict within the context of modern governance discourse. The unilateral implementation of strategies for stratospheric aerosol injection, which has arguably been viewed as a strategy for modifying solar radiation, can be interpreted as a threat to national security, thereby prompting the application of armed response practices on one hand and rendering international law incapable of mediation. Specifically, the jus ad bellum system presents few obstacles to potentially harmed states whose perceived material interests are regarded as being put in jeopardy by a climate-related intervention by another.

Such confrontations are quite thoroughly evidenced through scenario-based analysis. A group of climate-sensitive states facing the acute threat of adverse outcomes can choose unilateral solar radiation management to counter the expected vicious effects, and the indecision of less powerful actors will continue.

The following action of the so-called Great Powers would be based on geopolitical orientation as well as on the perceived importance of the intervening state’s actions; accommodation through cooperativeness stands separately in their place as a possible action, to be replaced with direct military conflict. The cancellation of such programmes may even turn out worse than establishing them, as the sharp increase in global temperatures would cause the so-called termination shock, with grave consequences felt worldwide.

These risks are aggravated by the fact that climate engineering research has been consolidated into the defence and intelligence sectors. US institutional actors have not only promoted a militarised outlook on solar geoengineering, viewing it as a weapon in geopolitical competition, but have done so in a manner that implicitly suggests the problem, the eventual utilisation of the technology-is itself normal and unavoidable.

It is not hard to see the source of tensions here between a fossil-fuel-based American hegemony and evaluations that know the problem of climate change as a national security issue. Although the temporal and spatial nature of climate engineering suggests possible ways of bridging such opposing interests, such militarisation represents the dual risk of weaponisation of planetary management.

Climate engineering governance also forms a critical realm of geopolitical research. It is essential to reconfigure international environmental law and institutional setups on a systemic level to address the intricacies of climate engineering. Emerging conceptions of the planetary commons provide a valuable framework for reimagining existing state-centric paradigms. The idea of treating the critical Earth system functions as a global common, to be governed collectively, provides the normative scaffolding for a just regime of climate intervention.

However, such governance innovations also need to address fundamental power imbalance as opposed to simply addressing their collateral. Building real Global South capacity requires more than mere financial transfers; it should involve a change of research priorities, institutional structures, and patterns of decision-making. These actions should be based on the development of appropriate climate models that take into consideration Southern conditions, support indigenous knowledge systems, and give the communities that might be affected by the interventions veto powers.

Democratic legitimacy is a key issue within any governance system. Although some believe that climate engineering is completely unbound by democratic governance due to its technical applications and global operation, others view that democratic structures are strong enough to cope with such technologies as long as they are well-designed. The inflexion points mark a shift away from the procedural version of democracy and toward the substantive version of participation, in which concerned communities can take ownership of research agendas as well as deployment choices.

The politics of controlling climate engineering technologies will significantly shape the geopolitical system of the coming century. Regardless of the outcome, a more equitable and democratic international climate will either be established, or a colonial order will emerge, leading to conflict. Alternate routes, however, are possible. The international community is also more likely to develop normatively legitimate governance of climate intervention by prioritising justice as an ethical and policy issue, by structuring its institutional arrangements to be more inclusive, and by resisting the unilateralism of great powers.

Climate engineering governance will shape the geopolitical system of the coming century, justice or conflict hangs in the balance.

The result means that climate engineering should not only be understood as a technical engineering issue, but rather as a fundamental inquiry concerning planetary sovereignty and democratic equal management. The stakes are, in fact, very high; whether Earth will be habitable in the future and whether the global order will be legitimate are determined by the present choices. At this fateful juncture, it has never been clearer that the necessity of righteous rule must be observed.

The decisions made today regarding the governance of climate engineering will determine whether humanity’s response to the climate crisis represents the best understanding of global governance and justice that humanity can achieve, or the worst we know of in terms of stewardship and mutual support.

Disclaimer: The opinions expressed in this article are solely those of the author. They do not represent the views, beliefs, or policies of the Stratheia.