We’ve reached the “what if we just make it snow a lot to save Antarctic’s ice sheets” phase of our time on Earth. Good job, everyone.
What sounds like a discussion climate scientists would have after eating a bunch of weed brownies is actually the premise of a new paper out in Science Advances last week. Researchers crunched the numbers on a massive geoengineering modelling experiment to learn what it would take to shore up the most imperilled glaciers on Earth. The results focus on pumping massive amounts of artificial snow onto the surface to stabilise West Antarctica’s glaciers, an idea that would staunch sea level rise but could also have a host of unintended consequences. These types of thought experiments, while interesting to gauge all options humanity has to deal with climate change, also show how desperation could lead to some dangerous decisions by policymakers if carbon emissions aren’t cut soon.
West Antarctic is ground zero for the sea level rise crisis. The coastal glaciers hold back an ice sheet that would raise sea levels more than 10 feet if it melted entirely, but they’re being undercut by warm water . The bedrock beneath them slopes downward as you travel inland, creating an unstable situation that could lead to runaway collapse. Their eventual collapse is possible even if the world meets the Paris Agreement goals, and if that happens it would completely reshape the shorelines of the world.
“There is no alternative to reducing carbon emissions to zero and keeping the Paris Climate Agreement, but even if without further warming the planet we have already caused serious damage,” said Anders Levermann, a climate scientist at the Potsdam Institute for Climate Impact Research who worked on the study. “One process that is currently unfolding in West Antarctica caused by a warming of the ocean, is that all of the marine ice of West Antarctica will discharge into the ocean.”
Previous wild thought experiments for how to deal with this include a proposal for a massive underwater berm to stop warm water from intruding beneath the glaciers. But the new study looks at another avenue of saving the glaciers by increasing snowfall onto the surface to thicken the ice. The process that could in theory stabilise them by adding heft that would push the grounding line—where the ice, seafloor, and ocean meet—further out to sea.
Researchers used a climate model to simulate the ice sheet’s continued meltdown and then cranked up the snowfall on it, which in turn would become ice as it gets compacted down. The findings show that adding up to 32 feet (10 metres) of ice per year over the course of 10 years would be enough to protect the West Antarctic glaciers from completely destabilising if our currently warmed-up climate stayed constant. That would amount to adding 7,400 gigatonnes or billion tons of ice. As Jane Flegal, a science policy expert and adjunct faculty member at Arizona State’s School for the Future of Innovation in Society, pointed out, that’s six times the volume of the Panama Canal.
“For context, I think [Southern California ski resort] Big Bear’s artificial snow system can make roughly 20 tons of snow per minute (at optimal capacity),” she said. “So to do this, some system (powered by zero-carbon energy, I’d hope) would have to run Big Bear’s artificial snowmaking, which is pretty serious, for 700,000 years.”
“People have to understand that if we do not want to lose our cities we have to do something. We just laid out one possibility.”
So yeah, there are a few slight technical impediments that would need to be worked out on the snowmaking end. The study itself acknowledges that, noting that it would require pumping ocean water 2,100 feet (640 metres) in elevation to the glacier surfaces, desalinating said water, and then blowing it as snow or finding a way to store it long enough to freeze. This would require massive amounts of energy—the study notes the pumping alone would require 12,000 high-powered wind turbines to generate enough electricity—all in one of the harshest, most remote places on Earth. And the study notes, it might not even work, or it could have unintended consequences from dropping global sea levels a few inches due to all the water pumping to completely screwing up ocean circulation patterns.
“I am not proposing to do what we have shown to be possible but that is a decision for society,” Levermann said. “People have to understand that if we do not want to lose our cities we have to do something. We just laid out one possibility.”
That scientists are even laying out this seemingly wild-eyed scheme as a possibility illustrates a few things. The first is that we are in a bad place when it comes to climate change. Science has shown the risks for decades on end yet humanity has continued to pump carbon pollution into the atmosphere. And so researchers are starting to examine what even a few years ago were taboo research areas, like geoengineering the crap out of ice sheets to save coastal cities from being swamped. Frankly, this should freak you out.
The second is that from a governance perspective, geoengineering is the Wild West. And if a few governments with major coastal populations decided to try to do this or say, a rogue billionaire decided to pump the sky full of sun-blocking particles, there could be unintended consequences.
Those possible consequences include the aforementioned ocean circulation and sea level drops, and the fact that it might fail. But Flegal also noted there are “societal risks of assuming the feasibility of something that is likely to be impossible.”
Across the Atlantic, there's already a presidential candidate saying he’d execute some geoengineering schemes if elected, including “shoring up glaciers.” Putting our faith in these types of moonshot schemes could leave society even less prepared than it already is for the changes coming our way.
Featured image: NASA ICE (Flickr)