Solar geoengineering (SGE) is an emerging technology that has the potential to help cool our warming earth. It works quickly, it’s cheap, and it can cool large areas of the globe.
It’s also an addictive Band-Aid with long-term consequences that are not fully understood..
Matthew McGinty, a professor of economics at UWM, is a co-author of a recent paper published in the Journal of the Association of Environmental and Resource Economists. In it, he and his collaborators explore the possibility that a single nation, called a ‘free driver,’ begins to use SGE to cool the planet.
The paper examined voluntary climate change agreements between nations and looked at them as a series of questions: Do they want to participate in an agreement, like the Paris Accords or the Kyoto Protocol? How much should they choose to reduce emissions by? Can the nations form a coalition? Then, the authors added another scenario: What if countries had the option to implement solar geoengineering?
“What we show is that you can actually ‘crowd in’ emissions if the threat of this free driver is out there, and you can be damaged by them doing too much geoengineering,” McGinty explained. “If one nation uses it, it could harm other nations.”
Here are three things you need to know about McGinty’s research and SGE.
1. Solar geoengineering is a Band-aid, not a solution.
SGE is still 5-10 years from being realized, but McGinty and other researchers know that it’s coming, and it needs to be studied.
SGE refers to a spate of technologies that reflect the sun’s energy away from the Earth’s surface, thereby cooling the temperature. These include methods like covering rooftops in reflective paint or placing large mirrors in orbit around the planet. But the most cost-effective technology, and therefore most likely to be implemented, is called stratospheric aerosol injection (SAI). That involves using airplanes to distribute particulates into the upper atmosphere, mimicking a natural cooling phenomenon that scientists observed when a volcano erupted in the Philippines in 1991. The fine particles that spewed into the air caused a .5 degrees Celsius cooling effect around the world over the next year.
SAI is also inexpensive, costing as little as $20 billion per year when other mitigation strategies cost in the trillions of dollars.
But there are pitfalls – namely, SGE does not address the emission of greenhouse gases like carbon dioxide. While SGE would cool the earth, greenhouse gases would continue to be emitted, and other consequences, like the acidification of the oceans, would still occur.
Also, SGE is a short-term solution. The cooling effect would last for a year or two at best, and then SAI particulates would have to be “re-upped” every so often to achieve the effect again.
“So, once you start to use this technology, it becomes addictive,” said McGinty. “If you stop, you could have a massive rebound in temperature.”
2. There are no international climate agreements in place that include SGE, and anyone could start using it.
McGinty studies international climate agreements, particularly through the lens of game theory. Game theory assumes that nations, despite their promises, will ultimately act in their own self-interest. While climate agreements like the Paris Accords say that countries pledge to reduce their emissions to achieve specific targets on a set timeline, they are non-binding and there are no ramifications if countries fail to meet their goals.
The paper posed the question: What would happen if any of those countries decided to use SGE on their own?
This is what McGinty and his co-authors refer to as the ‘free driver’ problem. In economics, a ‘free rider’ is a person or entity that benefits from the actions of another without putting in work themselves. In a climate agreement, a free rider is any nation that does not contribute to climate change mitigation efforts, but nevertheless enjoys the benefits of those efforts.
A free driver would be the opposite: An entity or nation that takes on the individual task to reap individual benefits without regard for others. The countries that have the means to deploy these technologies would likely be the United States, China, or Russia, but a rogue nation state like North Korea or even an individual billionaire could decide to implement them, given how inexpensive SGE is.
And that could be bad news for the rest of the planet. “Potentially, it’s going to change global precipitation patterns. There are unknown long-term side effects,” McGinty warned.
Countries could try to curb a free driver by imposing sanctions or embargoes on the rogue actor, but that wouldn’t be enough to stop SGE. “If you were even to pay money or embargo or stop one driver, the next driver emerges,” McGinty pointed out. “You can’t sanction all of (them).”
3. Despite consequences, SGE may inspire initiatives to lower greenhouse gas emissions.
It all goes back to game theory. McGinty thinks the fear that a rogue state or individual could deploy SGE technology outside of the framework of a climate agreement could be enough to encourage nations to begin cutting their emissions.
“That’s the underlying takeaway from our paper. … We call it an ‘anti-driver’ effect. If the damages from the free driver using too much geoengineering are too high, then you protect yourself by reducing your emissions so they don’t use it,” McGinty explained.
Hypotheticals and reality
Why plan for these hypothetical scenarios? SGE is still 5-10 years away, and global relationships and the climate itself are always in flux.
But McGinty thinks that if SGE is part of the future, we need to start planning for it now.
“The question becomes, who gets to decide where the global thermostat is set, and are we going to have an agreement on that?” McGinty said. “If we can understand the individual incentives, then we can think about how to design an agreement that people can join. … It also tells us that if this technology is out there, then maybe that can lead us to agreements where we actually do solve the underlying problem of emissions.”
Until then, McGinty and his colleagues will continue their research. Scientists and governments can’t afford to ignore solar geoengineering, and McGinty worries that the day is coming when his hypotheticals will be all too real.
By Sarah Vickery, College of Letters & Science