Preventing global warming from becoming a planetary catastrophe may take something even more drastic than renewable energy, superefficient urban design, and global carbon taxes. Such innovations remain critical, and yet disruptions to the Earth’s climate could overwhelm these relatively slow, incremental changes in how we live. As reports of faster-than-expected climate changes mount, a growing number of experts worry that we might ultimately be forced to try something quite radical: geoengineering.
Geoengineering involves humans making intentional, large-scale modifications to the Earth’s geophysical systems in order to change the environment. These can include sequestering atmospheric carbon dioxide in the oceans, changing the reflectivity of the Earth’s surface, and pumping particles into the stratosphere to block a fraction of incoming sunlight. Many of these proposals mimic natural events, so we know that—in principle—they can work, although there is insufficient understanding of their potential side effects. Unsurprisingly, geoengineering is highly controversial, and even proponents view it as a “Hail Mary” pass, to be considered only after all other options have failed.
But geoengineering presents more than just an environmental question. It also presents a geopolitical dilemma. With processes of this magnitude and degree of uncertainty, countries would inevitably argue over control, costs, and liability for mistakes. More troubling, however, is the possibility that states may decide to use geoengineering efforts and technologies as weapons. Two factors make this a danger we dismiss at our peril: the unequal impact of climate changes, and the ability of small states and even nonstate actors to attempt geoengineering.
For a variety of political and natural reasons, global warming affects some countries differently than others. Fragile economies and weak infrastructures tend to worsen the results of climate disruptions, a problem exemplified by Bangladesh’s vulnerability to monsoons, accelerating desertification in northern China, and, most visibly, Hurricane Katrina’s devastation in New Orleans. At the same time, warming and altered rainfall patterns may—temporarily—improve conditions for countries in extreme latitudes, increasing harvests in Canada and Russia for a few years. Similarly, intentional changes meant to fight global warming would also have differential results.
At the same time, the resources required for geoengineering projects can vary dramatically. A start-up company called Climos and the government of India have each begun to prepare tests of “ocean iron fertilization” to boost oceanic phytoplankton blooms, in order to extract carbon dioxide from the atmosphere, at a cost of just a few million dollars. At the other end of the spectrum, projects like the injection of megatons of sulfur dioxide into the upper atmosphere to simulate the effects of a volcano would easily cost in the tens of billions of dollars—still within the means of most developed countries.
It’s this combination of differential impact and relatively low cost that makes international disputes over geoengineering almost inevitable. Even if there is broad consensus that geoengineering is too risky, research into environmental modification will happen simply out of self-preservation—nobody wants to fall behind. Moreover, it’s not hard to imagine some international actors seeing geoengineering as something other than solely a way of avoiding environmental disaster.
It wouldn’t be the first time states looked at the environment as a weapon. In the early 1970s, the Pentagon’s Project Popeye attempted to use cloud seeding to increase the strength of monsoons and bog down the Ho Chi Minh Trail. In 1996, a group of Air Force and Army officers working with the Air Force 2025 program produced a document titled “Weather as a Force Multiplier: Owning the Weather in 2025” (it never went anywhere). The Soviet Union reputedly had similar projects underway. But although the idea of a geoengineering arms race may superficially parallel this line of thinking, it’s actually a very different concept. Unlike “weather warfare,” geoengineering would be subtle and long term, more a strategic project than a tactical weapon; moreover, unlike weather control, we know it can work, since we’ve been unintentionally changing the climate for decades.
The offensive use of geoengineering could take a variety of forms. Overproductive algae blooms can actually sterilize large stretches of ocean over time, effectively destroying fisheries and local ecosystems. Sulfur dioxide carries health risks when it cycles out of the stratosphere. One proposal would pull cooler water from the deep oceans to the surface in an explicit attempt to shift the trajectories of hurricanes. Some actors might even deploy counter-geoengineering projects to slow or alter the effects of other efforts.
The subtle, long-term aspects of geoengineering could make it appealing. Because the overt purpose of geoengineering would be to fight global warming, and because complex climate systems would make it hard to definitively blame a given project for harmful outcomes elsewhere, offensive uses would likely be hard to detect with certainty. And, in a world where nuclear deterrence remains strong but the value of conventional military force has come under question, states will look for alternative, unexpected ways of boosting their strategic power relative to competitors.
Despite the global impact of geoengineering, the differential climate patterns and the resilience of local technological, economic, and social infrastructures guarantees that some states will fare better than others. Much as Cold War nuclear strategists could argue about “winning” a nuclear war by having more survivors, advocates of a Global Warming War might see the United States, Western Europe, or Russia as better able to “ride out” climate disruption and manipulation than, say, China or the countries of the Middle East. It’s a new version of “thinking the unthinkable.”
Smart policies could lessen these risks. The 1977 Environmental Modification Convention, produced by the United Nations in response to Project Popeye, prohibits the use of engineered weather or environmental changes for military purposes; signatory countries may wish to look at ways of monitoring and enforcing this treaty. Outright banning of geoengineering research is highly unlikely, as it offers a last-ditch hope for staving off climate disaster. Instead, putting research into the hands of transparent, international bodies could reduce the temptation to “weaponize” geoengineering; internationalization could also help to spread the liability and costs, reducing one potential source of tension.
The best strategy to avoid the possible offensive use of geoengineering techniques, however, is twofold: First, embrace the social, economic, and technological changes necessary to avoid climate disaster before it’s too late; and second, expand the global environmental sensor and satellite networks allowing us to monitor ecosystem changes—and manipulation. This strategy may not reduce the temptation to look at geoengineering as an offensive capacity, but it would ensure that experiments and prototype efforts couldn’t readily be hidden under the cover of fighting climate change. We know all too well that the international contest for power will continue even in the face of a growing global threat. It would be a tragedy if, in seeking to avoid environmental catastrophe, we inadvertently enabled a new quest for geopolitical advantage. The risks of turning the Earth itself into a weapon are far too great.