In the race against global heating, a team of scientists is trying a novel strategy: pumping seawater onto Arctic ice to inhibit melting. But others have warned of potential dangers and labelled the effort a distracting, ineffective approach.
A small team of University of Cambridge researchers spent the last winter in the Canadian Arctic “drilling a hole in the sea ice that naturally forms in winter, and pumping around 1,000 litres of seawater per minute across the surface,” reports BBC News. “Exposed to the cold winter air, this seawater quickly freezes, helping to thicken the ice on top.”
The water also helps compact the snow, the news story adds. “As fresh snow acts as a good insulating layer, now ice can also form more easily on the underside in contact with the ocean.”
Success would be significant in the climate fight because ice reflects much of the sun’s warming energy back into space, whereas dark open water absorbs it. Significant polar ice gain could make a major dent in global heating.
That’s the hope that took the small team from the UK’s Cambridge Centre for Climate Repair to Cambridge Bay, Nunavut, to field test the process with a hydrogen fuel cell generator powering their pump. In the future, underwater drones powered by green hydrogen could perform the task, says Real Ice, the company leading the project.
The idea is, the thicker the ice at the end of winter, the longer it will survive in the melt season, said Real Ice’s Andrew Ceccolini.
Sea ice within the small study area did thicken by a “few tens of centimetres” over the course of the test, reports BBC. Now, local residents will monitor the experiment as winter turns to spring and summer.
But the jury is still out on the merits of the plan, the BBC writes. “We don’t actually know enough to determine whether this is a good idea or bad idea,” acknowledged team lead Shaun Fitzgerald.
Other scientists who were not involved in the project remain skeptical. “The vast majority of polar scientists think this is never going to work out,” said University of Exeter glaciologist Martin Siegert. There is the possibility that the saltier, manufactured ice will melt more quickly in the summer, since salt water has a lower freezing point than fresh and needs to absorb less heat before it begins melting.
Scaling up the project would also demand a huge energy input. “One estimate suggests that you could need about 10 million wind-powered pumps to thicken sea ice across just a tenth of the Arctic,” writes the BBC.
Others fear unintended consequences. “Geoengineering technologies come with enormous uncertainties and create novel risks for ecosystems and people,” said Lili Fuhr, director of the Fossil Economy Program at the Center for International Environmental Law, adding that the ice thickening plan could well contain just such risks.
“The Arctic is essential to sustaining our planetary systems,” she said. “Pumping seawater onto sea ice on a large scale could change ocean chemistry and threaten the fragile web of life.”
Detractors also fear that the endeavour, like all efforts to “geoengineer” a solution to global heating, will be nothing more than a dangerous distraction to the primary job of slashing emissions. “The way to solve this crisis is to decarbonize: it’s our best and only way forward,” Siegert said. He described the seawater-to-ice project as “insane” and something that “needs to be stopped.”
Fitzgerald and his team are “acutely aware of these concerns,” writes the BBC.
“We’re not here promoting this as the solution to climate change in the Arctic,” Fitzgerald said. “We’re saying that it could be [part of it], but we’ve got to go and find out a lot more before society can then decide whether it’s a sensible thing or not.”
The reality is that even with steep emissions cuts, the Arctic will remain in peril from heat already baked into the system. “We need other solutions,” said Centre for Climate Repair PhD student Jacob Pantling, who spent the winter in Cambridge Bay. “We have to reduce emissions, but even if we do… as quickly as possible, the Arctic is still going to melt.”
