Turns Out A Wild Geoengineering Plan To Refreeze Arctic Sea Ice Isn't The Best Idea
by Brian Kahn
As the world spins closer to climate catastrophe, fringe ideas are inching toward the mainstream. Geoengineering is among the topics that were once verboten but are now finding traction. And that includes some pretty out-there ideas, including ones focused on saving polar ice by pumping massive amounts of seawater onto the surface of ice, where it will refreeze quicker and strengthen all icepack against melting.
The refreezing idea has been proposed for both poles and would be massively expensive. But a new study shows that, in the Arctic, saving sea ice would do little to slow the climate crisis elsewhere. And it would unleash shocking and unintended consequences in the Arctic itself.
The paper, published in Earth’s Futures on Thursday, takes its inspiration from a previous study that first raised the prospect of an Arctic geoengineering project. That study outlined a proposal to install wind turbines across the Arctic that would power pumps to draw water to the surface of the remaining sea ice, where it would refreeze more quickly than from the bottom-up.
Sounds a little bit (OK, a lot) radical to be sure, but the rapidly warming Arctic needs all the help it can get. Old sea ice that used to hold the icepack together is all but gone, and we could see an ice-free Arctic as early as the next decade if carbon pollution isn’t slowed soon.
But while the previous research showed it was technologically feasible to do the wind turbine thing, it didn’t look too hard at what the climate ramifications would be. The new paper picks up at that point because, as Lorenzo Zampieri, the new study’s lead author and PhD student at Germany’s Alfred Wegener Institute, told Earther, “this geoengineering idea had never been tested with a climate model and, in our opinion, this was a necessary step to contextualise this approach.”
The scientists used an advanced climate model to explore what the scheme would actually do to the Arctic. They modelled a number of scenarios, including one idealised scenario in which seawater was pumped over the entirety of the sea ice. That model found that ice would grow up to 65 metres thick over the rest of the century, a huge change from the average historical thickness of 1.8 metres.
They dialled things back to a bit more “realistic” scenario that aimed for an average thickness of around 2 metres and moderately spaced out wind mills and pumps. The good news: It would indeed help refreeze.
But the less good news is that the process would radically alter the climate in the Arctic while doing very little to fix the global climate overall. Healthy, reflective ice that lasts through the summer would restore the late summer Arctic climate to some semblance of its former self.
Pumping throughout the winter, however, would result in an unintended warming for parts of the Arctic in the latter half of the century. That’s because as the ice freezes, it releases energy in the form of heat. Layer that on top of the warmth from global warming, and you have a recipe for a very confusing Arctic winter.
Oh, and speaking of that global warming: While saving Arctic sea ice is great for polar bears and the people who live there, it does just about jack shit for the climate globally. The mid-latitudes, where most humans live, would see just a few hundredths of a degree of cooling as a result. That’s nice and all, but it ain’t gonna do much to save the coral, stop wildfires from burning out of control, or keep people from dying.
This type of modelling will be crucial in the coming decade to understand the options we have on the table. Other forms of geoengineering, like blocking sunlight or undertaking massive reforestation projects to suck carbon out of the air, are also gaining steam as the climate we so rely on keeps unravelling.
There’s a seductiveness to thinking we can just implement a few techno fixes to buy time while the world gets its act together drawing down emissions, but the reality is they will almost surely come with tradeoffs and gnarly surprises of their own.
“I would like to point out that, according to our findings, this approach could only buy some decades to the Arctic sea ice, while a permanent solution can only be achieved by reducing the excess of greenhouse gasses in the atmosphere and cooling the climate,” Zampieri said.
That’s right. The best thing we could do for the climate and future generations is the one the world has so far failed at. It might not be as sexy as building huge wind turbines in the Arctic, but it damn well gives us a better chance at survival.