- Written by Mark Pointing
- BBC News climate correspondent
Ice rescue: a daring experiment or a dangerous distraction?
On the sea ice off Canada's northern coast, scientists wearing parkas watch as salty water flows over the frozen ocean.
Their goal? To slow global warming.
As sea ice disappears, the dark ocean surface can absorb more of the sun's energy, accelerating global warming. So the researchers want to increase its thickness to prevent it from melting.
Welcome to the most ridiculous side of geoengineering – deliberately interfering with the Earth's climate system in an attempt to counteract the damage we have done to it.
But more experimental measures are aimed at moving forward, seeking to reduce the energy absorbed by the Earth.
Many scientists strongly disagree, warning that such attempts distract from the crucial step of cutting carbon emissions and risk doing more harm than good.
But a small number of advocates claim that their methods could provide a helping hand to the planet as humanity cleans up its act.
The ultimate goal of the Arctic experiment is to thicken sea ice enough to slow or even reverse the ice melt we've already seen, says Dr. Sean Fitzgerald, whose team at the University of Cambridge's Center for Climate Reform is behind the project.
Will it work or is it, as one scientist put it, “completely crazy”?
“We don't actually know enough to determine whether this is a good or bad idea,” Dr. Fitzgerald admits.
“It's too cold,” say the researchers. The cold winds in Cambridge Bay can make it feel like -45°C
The researchers encountered harsh conditions in Cambridge Bay, a small Canadian village located in the Arctic Circle.
“It's very cold,” Andrea Ciccolini of Real Ice, a British company leading the trip, told me over a patchy Zoom call from inside a fluttering white tent.
“The temperature is around -30°C with strong winds, making it as low as -45°C with the wind chill factor.”
They drill a hole into the sea ice that naturally forms in winter, and pump about 1,000 liters of seawater per minute through the surface.
When exposed to cold winter air, seawater freezes quickly, helping to condense the ice above. Water also compresses ice. Since fresh snow acts as a good insulating layer, ice may now form more easily on the underside in contact with the ocean.
“The idea is that the thicker the ice [at the end of winter]“The longer they survive when we get into the molt season,” Mr. Ciccolini explains.
A pump is used to flood the surface of the sea ice with seawater, which will then freeze
As they talked to me at the end of their trip, they had already seen a few tens of centimeters of ice thick across their small study area. The ice will be monitored by locals in the coming months.
But it's still too early to say whether their approach can actually make a difference in the rapid decline of Arctic sea ice.
“The vast majority of polar scientists think this will never work,” warns Martin Siegert, an experienced glaciologist at the University of Exeter, who was not involved in the project.
One problem is that saltier ice may melt more quickly in summer.
Then there's the huge logistical challenge of scaling the project to a reasonable scale – one estimate suggests you would need about 10 million wind-powered pumps to increase sea ice density across just a tenth of the Arctic.
“It's crazy in my opinion that this is being done on such a large scale in the entire Arctic Ocean,” says Julianne Struve, professor of polar observation and modeling at University College London.
Some of the more experimental geoengineering suggestions include trying to make clouds more reflective by generating additional sea spray, and simulating volcanic eruptions to reflect more of the sun's energy back into space.
A number of scientists – including UN climate and weather bodies – have warned that these approaches could pose serious risks, including disrupting global weather patterns. Many researchers want to see them banned completely.
“Geoengineering techniques come with enormous uncertainties and create new risks for ecosystems and people,” explains Lily Fore, director of the Fossil Economy Program at the Center for International Environmental Law.
“The Arctic is essential to maintaining our planetary systems: large-scale pumping of seawater into sea ice could alter ocean chemistry and threaten the fragile web of life.”
There is a more fundamental and widespread interest in this type of project.
“The real danger is that it provides a distraction, and people with vested interests will use it as an excuse to continue burning fossil fuels,” Professor Siegert warns.
“Frankly, it is crazy and must be stopped. The way to solve this crisis is to decarbonize: it is the best and only way forward.”
Arctic researchers are keenly aware of these concerns. They stress that they are simply testing this technology, and will not unleash it on a larger scale until the risks are better known.
“We're not promoting this here as the solution to climate change in the Arctic,” Dr. Fitzgerald stresses.
“We say it can be [part of it]But we have to go and find out more before society can then decide whether this is reasonable or not.”
They agree that geoengineering is not a silver bullet for tackling climate change, and that sharp reductions in fossil fuels and carbon emissions are critical to avoiding the worst consequences of global warming.
But they point out that even with rapid action, the world still faces a difficult future.
The Arctic Ocean is likely to become virtually free of sea ice by the end of at least one summer by 2050, and perhaps even sooner. As the chart below shows, they have actually seen sharp declines since the 1980s.
“We need other solutions,” says doctoral student Jacob Bantling, a researcher at the Center for Climate Reform who braved icy winds in Cambridge Bay.
“We have to reduce emissions, but even if we do it as quickly as possible, the Arctic will continue to melt.”