Big science for refreezing the Arctic ice cap: Bob McDonald

Scientists have proposed a massive geoengineering project to to restore the melting Arctic ice cap.

Millions of wind turbines proposed to power Arctic ice-making

An idea for a radical mega-project involving a large network of windmill-powered water pumps scattered across the Arctic could reverse the dramatic loss of sea ice due to climate change, researchers say. But it will cost billions and could have unknown side effects.

One of the more serious effects of climate change is the dramatic loss of sea ice during summers in the Arctic Ocean. The white ice and snow at the top of the world can reflect as much as 90 per cent of sunlight that falls on it back into space, which in turn helps keep the planet cool.

Depiction of Arctic sea ice cover on Sept. 12, 2013, close to the annual minimum, with a line showing the 30-year average minimum extent in yellow. (NASA Goddard's Scientific Visualization Studio/Cindy Starr)

If the present warming trend continues, however, permanent summer ice in the Arctic will be gone by the 2030s, possibly sooner. In turn, darker seawater would then absorb much of the sunlight, accelerating global warming. Scientists are worried because that could set off a chain reaction of other effects, such as melting permafrost, which releases methane — another, more potent greenhouse gas — compounding the problem even further in a vicious cycle called a feedback loop.

Of course, the best solution to the problem is to cut off the source of accelerated planetary warming — the burning of fossil fuels. But political efforts, such as the Paris Agreement, which aims to slow the production of those gases, will likely not be enacted fast enough to save the permanent Arctic ice cap.

So rather than wait for the world to transition away from fossil fuels toward alternative forms of energy production, geoengineers at Arizona State University are proposing a radical idea to save the ice before it's gone. They're proposing a series of windmill-powered pumps stationed around the Arctic that would pump water from below the ice up onto the surface, increasing the ice growth during winter and compensating for ice loss during summer.

A wind turbine on the Scottish moors - not quite as harsh conditions as you'd find in the Arctic Ocean. (Richard Dorell, copyright cc-by-sa-2.0)

In the Arctic Ocean, ice freezes from the bottom up. Even though we see images of the frozen north with snow everywhere, the northern climate is actually quite dry, so there isn't much snowfall to add to the ice from above, as happens on glaciers farther south.

As water freezes, it must lose heat. Usually, that heat migrates up through the ice itself and is carried away by cold air. But as the ice grows thicker, it begins to act as an insulating blanket, making it more difficult for the heat to get through, so the heat remains in the water, slowing the growth of ice.

The idea is to speed up the release of heat by pumping water from under the ice onto the surface where it will lose heat to the air faster, then freeze in place, forming in an extra layer on top at least a metre thick. If 10 per cent of the Arctic ice were to be enhanced this way, it would be enough to compensate for the current rate of loss.

NASA ICESCAPE scientists watch as the US Coast Guard icebreaker Healy cuts a path through multiyear Arctic ice. (NASA/Kathryn Hansen)

Of course, there will be challenges designing windmills and water pumps that will work throughout the frigid Arctic winter, but that's a problem scientists can leave to the engineers.

There is just one little catch. This is not a modest proposal. It will take a lot of windmills. About 10 million of them, constructed at a rate of a million per year over 10 years at a cost of about $50 billion USD.

To put that into perspective, Canada currently has roughly 6,200 wind turbines connected to the grid in the entire country. Building all those machines, installing them and maintaining them in the harsh conditions of the far north would be an enormous international effort involving Canada, Russia, the US, Norway and other circumpolar countries.

This is another case of scientists coming up with an Earth-changing mega-project in the same class as the idea to spray sulphur particles into the atmosphere and create a global haze to shade the Earth from sunlight.  

Both ideas come with tremendous price tags and both could have unforeseen global side effects such as shifting weather patterns, changing ocean currents, not to mention the effect on wildlife.

The scientists agree that these are desperate measures to prevent our planet from overheating and suggest the best solution to the problem is to move away from fossil fuels. But since that is not happening fast enough, they are doing the calculations now to show these crazy ideas might actually work if we become truly desperate.

A more sensible idea might be to take that $50 billion and put it towards research into alternative energies, but in light of the recent decision by U.S. President Trump to open the Arctic to more drilling for oil and gas, it looks like, in the short term, oil derricks might be more likely to rise above the northern landscape than windmills.


Bob McDonald is the host of CBC Radio's award-winning weekly science program, Quirks & Quarks. He is also a science commentator for CBC News Network and CBC-TV's The National. He has received 12 honorary degrees and is an Officer of the Order of Canada.