Here’s a scenario that seems plausible if we continue down our current path of only vaguely paying attention to climate change: There’s a drought in northern China, almost certainly exacerbated by global warming. People are dying. There’s famine and huge waves of migration out of the region. The government, not known for being calm in a crisis, faces enormous social unrest, and so it resorts to a drastic plan to change the weather, spraying sulfate aerosols–a combination of water vapor and sulfur–out of jets flying high in the sky. The wind carries the aerosols across the planet, eventually increasing the Earth’s albedo (its ability to reflect sunlight back into space) enough that the process of global warming is offset, even if greenhouse gas levels continue to build up in the atmosphere. The earth’s warming is alleviated for a time and, as a result, so are China’s droughts.
The operation wouldn’t cost much in the grand scheme of the world’s largest economies–on the order of billions of dollars per year, according to David Keith, one of the most prominent geoengineering proponents and a professor of applied physics and public policy at Harvard–and a sulfate aerosol spraying initiative with global ramifications could be done from a single airbase. The aerosol spraying could make the sky whiter, perpetually reminding us of how we’ve altered the climate. But how much would that matter if the world could preserve itself as it is today, avoiding the inevitable die-offs from long-term climate change? And in any case, how could the global community stop a country like China or India if it wanted to implement a geoengineering scheme without consent from the rest of the world?
These aren’t rhetorical questions. Over the last few months, scientists have started to more seriously tackle the questions surrounding geoengineering’s ramifications. And there’s a real possibility that altering the environment will be an option on the table at the upcoming international climate talks. If we have the technology, some countries–especially ones that didn’t get to reap the benefits of pumping out a planet-destroying amount of carbon–might argue, why aren’t we using it?
The sulfate aerosol scenario, a type of solar-radiation management (SRM), isn’t the only way to engineer the Earth’s climate so that it suits humanity’s needs, but because it’s relatively cheap and easy, it is one of the most likely schemes to be implemented. The concept of SRM has been around for decades, but interest in the topic has skyrocketed in the past few years, as the scale of climate change’s potential destruction has emerged. Sulfate aerosol spraying has a huge downside, however: once you start, you can never stop. A halt in the scheme would cause temperatures to rise rapidly, with potentially catastrophic results.
The concept of geoengineering goes back to at least the mid-1800s, when meteorologist James Pollard Epsy posited a method for generating artificial rain during droughts. In the 1960s and 1970s, geoengineering on a large scale started being taken seriously, as the former USSR considered ways to warm its tundra and turn it into farmland, according to the U.K.’s Royal Society.
Today, there are two basic approaches for geoengineering planetary systems to reduce climate change: SRM and removing carbon dioxide from the atmosphere (Keith is president of a company called Carbon Engineering that has developed a technique for capturing CO2 from the air). Unlike SRM, scrubbing CO2 from the atmosphere eliminates the root cause of climate change (removing CO2 from the atmosphere) instead of just alleviating the symptoms (cooling the planet, but leaving greenhouse gases in the atmosphere). But it has its downsides–what should be done with all the captured CO2? Companies in the space have a variety of ideas, including making plastic and fuel out of scrubbed CO2.
Getting an SRM scheme off the ground, says Clive Hamilton, a professor of public ethics at Charles Sturt University and author of Earthmasters: The Dawn of the Age of Climate Engineering, “would be a substantial operation, logistically, and it’s almost certainly going to involve the military one way or the other because it’s of such strategic importance.”
Hamilton believes that a nation will only launch an SRM scheme out of true desperation. The most likely first actors are countries like China and Russia, though it’s also not out of the question that the U.S. would launch an SRM project, perhaps after a series of costly weather disasters linked to climate change. China, in particular, has the right recipe: a calculating government that’s unconcerned with opposition and interested in clinging onto power no matter the cost. There wouldn’t be much anyone else could do about it without inciting war, aside from imposing diplomatic or trade pressure.
Luckily, none of this is likely to happen in the immediate future, mainly because the symptoms of climate aren’t yet bad enough to force any country to resort to geoengineering–and inciting the global panic that would certainly ensue. That means there’s still time to create a global structure for governing geoengineering research.
A 2010 paper published by Keith and colleagues suggests “a transparent, loosely coordinated international programme supporting research and risk assessments by multiple independent teams.” Keith, the author of a recent book called A Case for Climate Engineering, stresses that he thinks research should be allowed to proceed. “The dominant thing is fear that talking about doing this will distract attention from what emissions [are doing],” he says. “I don’t see an ethical or political justification for suppressing information about something potentially this useful to both humans and the natural world on account of that reaction.”
Hamilton, on the other hand, compares the governance of geoengineering schemes to that of nuclear and biological weapons. An international institution for building trust and transparency should be built, he says, to reduce the risk of any one country unilaterally deploying (or developing the capacity to deploy) an SRM program.
The topic of geoengineering has remained outside mainstream political discourse, but that may change soon. In February, The National Academy of Sciences released two long-awaited reports with the aim of providing “a careful, clear scientific foundation that informs ethical, legal, and political discussions surrounding geoengineering.”
The reports, which focused on reflecting sunlight to cool the Earth (i.e. sulfate aerosol spraying) along with CO2 removal and sequestration, weren’t exactly a ringing endorsement. The scientists behind the NAS reports believe carbon dioxide removal techniques need more research and development, but shouldn’t be ignored completely.
Reflecting sunlight, on the other hand, is a more complicated case. “Without reductions in atmospheric carbon dioxide levels, the amount of albedo modification required to offset greenhouse warming would continue to escalate for millennia, generating greater risks of negative consequences if it is terminated for any reason,” the researchers write.
But whatever the risks involved, now that the NAS committee has weighed in on geoengineering, governments across the world may start taking the concept more seriously. Hamilton has been told that people in the U.S. State Department are worried that the “geoengineering hand grenade” might be thrown into the middle of climate change negotiations in Paris at the end of the year, potentially derailing global agreements.
Whatever happens, schemes like sulfate aerosol spraying will certainly be considered more thoroughly in the years to come as technology develops and climate conditions change. It is not, Keith suggests, a binary choice. SRM could ostensibly complement carbon emissions mitigation schemes. “I don’t think the right response is to hide from it,” he says.