One underappreciated, terrifying aspect of climate change is that the situation would be even worse if our air pollution weren’t cooling us.
Aerosols from air pollution and smoke are providing a temporary cooling effect, offsetting somewhere between 0 to 0.8 degrees Celsius of surface temperature rise, according to the most recent Intergovernmental Panel on Climate Change (IPCC) report. Another study put the mean cooling at 0.7 degrees Celsius, or around 1.3 degrees Fahrenheit. In terms of the climate system, that small number is a big deal.
This makes the efforts of governments worldwide to clean up the air a “Faustian bargain,” in the words of climate scientist James Hansen. As we undertake this necessary project over the next decade or two, we need to also plan for more rapid warming, because we are essentially unmasking some baked-in heat. Hansen has warned that the rate of warming could double in the next 25 years.
This, falling on top of what is already a climate emergency, means we need rapid ways to cool the environment. Quickly phasing out the production of coal, oil, and gas would be the best action. But governments are on track to increase fossil-fuel production. If our leaders don’t turn away from fossil fuels — like, right now — people may soon be grasping for a mechanism that will change the climate sooner rather than later. Solar geoengineering is one quick-acting proposal.
Imagine a fleet of custom-designed aircraft taking off each day to release particles into the stratosphere. These particles — sulfates, or calcite, or something TBD — would reflect a fraction of incoming sunlight. They would circle around the planet, staying aloft for about a year. Every day like clockwork: new particles going up, old particles drifting down. The effect would be to cool the earth.
The idea of solar geoengineering, in particular stratospheric aerosol injections, is derived in part from scientists studying how volcanic eruptions have rapidly cooled the planet. But even though the effect would kick in rapidly, this would not be a short-term project. The program would need to be maintained for decades or centuries — until global warming stabilizes and enough carbon dioxide is removed from the atmosphere.
The prospect of managing the earth’s sunlight is an understandably horrifying proposition to some, akin to playing god. It is indeed a drastic measure. And the risks are not just ecological, but geopolitical. Many climate-security analysts are of the view that stratospheric aerosol injections would pose a “novel security risk” — that solar geoengineering is an emergent threat to be contained.
Solar geoengineering designed to reverse climate change could lead to armed conflict, or to its use as an unconventional weapon, warns a recent report on climate and security. Analysts caution about a “tug-of-war” over the climate, one that could spark “counter-geoengineering” or interventions by countries wanting different temperatures. Extreme weather events will be seen as engineered outcomes and subject to a “calculus of blame” in which individuals and groups may take revenge.
Other assessments suggest that China would be willing to deploy large-scale geoengineering, risking hostility with India. Or that solar geoengineering represents a national security tool that must be treated like nuclear weapons — a “coercive threat.” Or that there could be violent popular resistance to solar geoengineering. And so on.
Solar geoengineering is seen as so dangerous that a group of academics wrote a letter to Science suggesting that “unilateral, preemptive research” — as if studying something was itself a weapon — “risks exacerbating international conflict and undermining progress on energy system transformation away from fossil fuels.” They also argue that U.S. research is “likely to increase risks of militarization or securitization of this planetary-scale intervention.”
These debates about solar geoengineering tell us more about the assumptions and epistemologies of the people creating them than about what might actually happen with solar geoengineering — which in many important ways could be a force for peace and stability. How did we get to a point where policy and academic elites, activists, and cranks on the internet see solar geoengineering almost exclusively through the prism of threat?
First, we should consider what the science actually says about the prospects of solar geoengineering.
Modeling research has consistently shown that solar geoengineering “could offset some of the effects of increasing” greenhouse gases “on global and regional climate,” according to the IPCC. Scientists have found that solar radiation modification — as solar geoengineering is technically known — could substantially offset temperature rise. It also has the potential to mitigate a host of damaging impacts: the melting of Arctic sea ice and mountain glaciers; the weakening of the Atlantic meridional overturning circulation (AMOC), the ocean system that carries warm water to the North Atlantic; changes in extremes of temperature and precipitation; and changes in frequency and intensity of tropical cyclones. Modeling studies have found that it could possibly benefit some crop yields, and that even a moderate use of solar geoengineering can reduce physical and economic damage from climate change.
In other words, some of the climate-conflict linkages that concern security experts — floods and political unrest, heat waves and violence, agricultural production and instability — could be ameliorated by solar geoengineering. So could solar geoengineering actually be an instrument for peace?
Governments could use it to take anticipatory action, launching stratospheric aerosol injections to preempt conflicts arising from climate change. But given that most governments seem incapable of doing much about anything in advance — pandemic planning is Exhibit A — this particular environmental peace-building scenario seems unlikely. Rather, geoengineering might be used to preserve internal stability in times of crisis, to placate an anxious public dealing with climate migration, conflicts over water use, the maintenance of agricultural systems, and more.
An alternative scenario is that solar geoengineering may have a role in environmental peacemaking, bringing parties to agreement should there be conflict over the phaseout of fossil fuels. These concerns have been under-addressed in a world that tends to paint the energy transition as a pure, universal good. But a zero-carbon world produces zero-sum games, as international relations researchers observed in Nature. Consider that the geopolitics of phaseout may favor the U.S. and the European Union, which have diverse economies, wide access to renewable technologies, and money, all of which will be valuable in placating sectors that feel pain from the transition. Countries like Russia, the United Arab Emirates, or Saudi Arabia stand to lose in phaseout. Compounding the unevenness of decarbonization is a lack of promised aid for countries in the Global South — some of which are banking on revenues from oil and gas.
Critics of solar geoengineering dismiss it as ungovernable, given the difficulty of global political agreement. But is solar geoengineering more or less governable than the extremely complicated and conflict-rich problem of phasing out fossil fuels globally? Instead of fossil-fuel-producing countries dragging the planet into an existential death spiral, a truce could be accommodated in which solar geoengineering is used to smooth the transition.
In its best case form, solar geoengineering would buy time for decarbonization and carbon removal, as a temporary program that ramps up during the transition, then ramps down again over a century or so — “shaving the peak” off climate impacts.
As scholars Edward A. Parson and Jesse Reynolds note, there are problems with this model, which spurs the question: “Buying time for whom?” The answer is not for “the world” to decarbonize, but for producer nations to become less reliant on fossil fuels. Peace, then, is obviously not an unqualified good thing. Peace could be appeasement of fossil-fuel interests — solar geoengineering as a “peace for our time.”
Too many of our new technologies fail to be used in the public interest, for the public good. We are often biased toward assessing risks rather than the potentials of a new capability — which is somewhat reasonable, given the unintended consequences of so many emerging technologies and interventions. Yet this also contains grave downsides. Here, one risk is that the tremendous potential for security and peace is not applied to a topic where it is needed. Another is that viewing geoengineering exclusively as a security threat makes it more likely that it becomes that. More gravely, how we think about it is shaping the science that is done; it shapes what we know and what we are ignorant of. Fearing the dangers of solar geoengineering means that the world risks not knowing its full rewards.
Climate-policy professionals should also think about what a peace-centered approach to solar geoengineering governance would involve. Former U.N. secretary general Ban Ki-Moon, for example, has previously opined that solar geoengineering “risks exacerbating wider threats to international peace and security, such as resource scarcity and forced climate migration,” and thus needs a governance framework. Okay, but what would a framework that actively tries to further peace, and not just mitigate conflict, look like?
If such a framework is developed, and if an agency or institution is created to oversee solar geoengineering, we should explicitly put peace at the center of it. Scientific cooperation would be key to peace-centered governance, and it needs to be truly international. For example, some participants involved with a draft resolution on governing geoengineering, put forward at the U.N. Environment Assembly in Nairobi in March 2019, told researchers that solar geoengineering seemed like another “white man’s thing,” similar to programs administered by “global” institutions that threatened poorer countries and enforced behavior. Solar geoengineering demands a better version of genuinely international scientific cooperation.
We can’t afford to let our analysis be clouded by ideology, assumptions, and motivated reasoning on this topic — or any other. There’s more than the future of geoengineering research at stake here: Are we failing to see the whole picture with other emerging technologies, whether they be in the areas of biotechnology or computing? Are there other domains where we simply follow received wisdom about the uses of particular new capabilities? Technology could be a great friend in modifying ecosystems, earth systems, and ourselves — as long as we are not too scared to use it wisely.