Let's hope the scientists are all familiar with Ice-9 in Vonnegut's Cat's Cradle.*
From The Times (London & environs), June 22:
A government-backed team will soon start running field trials to ask whether thousands of robots could be deployed to thicken and preserve polar sea ice
For much of his career, Dr Shaun Fitzgerald of the University of Cambridge worked on trying to cut the amount of carbon we pump into the atmosphere. Five years ago, he shifted his focus. “We’ve been talking about reducing emissions for decades,” he said. “The truth is, they’re still rising.”
He turned his attention to something more radical. Could we, he wondered, refreeze the Arctic?
The idea has serious backing. In June the UK’s Advanced Research and Invention Agency (Aria) — a government body created to back “ideas on the edge of what’s possible” — awarded a team led by Fitzgerald £10 million in funding.
The money will be spent on exploring whether it might be possible to use hundreds of thousands of robots to thicken and prolong the life of a portion of the sea ice that forms each winter across the High Arctic.
Over coffee in a common room at Cambridge’s Department of Engineering, Fitzgerald explained that the basic physics is relatively straightforward. The ethics and engineering, however, are anything but.
The idea builds on well established knowhow. “Communities in the Arctic already build ice roads,” he said. “They drill holes, pump seawater on top and let it freeze to thicken the ice.”
The goal in Fitzgerald’s case is not strength as such, but longevity. The only long-term solution to global warming is to stop emitting carbon. But sea ice plays an important role in regulating the planet’s temperature by reflecting some of the sun’s energy back into space.
As global temperatures rise, the Arctic’s ice mirror is shrinking, with projections suggesting the region will, within 15 to 20 years, be entirely free of sea ice at the end of each summer. Reinforcing it, even modestly, could have a significant cooling effect, buying time to reach net zero.
Naturally, new sea ice forms from beneath. For this new ice to grow, heat must escape upwards, through the existing ice, allowing the seawater below to cool and solidify.
Snow, however, is an excellent insulator. When the ice has a layer of snow on it, the heat that must rise upwards is trapped, slowing the formation of new ice. If you flood the surface with seawater, the snow is washed away. Two things should now happen: the water on the surface will turn to ice and the rate of freezing below the ice should also increase.
Preliminary experiments last year involved drilling holes through sea ice and pumping water up. This “snow flooding” produced about 25cm of new ice on the surface, and a further 25cm below. “These are encouraging results, not conclusive ones,” Fitzgerald said. “We need much better data.”
The £10 million from Aria will fund laboratory tests, computer models and field trials. Controlled experiments will be conducted around Cambridge Bay, which lies along the Northwest Passage in the Canadian Arctic, across three winters, starting later this year.
If all goes well, the areas treated could be extended to up to about 1 sq km per experiment site. “The goal is to gather essential real-world data to rigorously assess if this intervention warrants further consideration,” Aria has said.
As well as tackling the engineering challenges, which include protecting equipment from temperatures that can drop below -40C, the team will assess environmental side-effects. What microbes are being brought to the surface? Is wildlife being disturbed?
Another question concerns albedo, or the reflectivity of the Arctic surface. Snow bounces away far more solar energy than bare ice. Ice, in turn, reflects more than open ocean. There is a chance, then, that removing snow and replacing it with ice could make things worse.
However, Fitzgerald believes that snow flooding could be done in the winter, when the Arctic is plunged into a months-long period of darkness. Since the sun is not shining, there is no solar radiation to bounce away. When the sun returns, a blanket of artificial snow could possibly be created, providing a bright insulating blanket that would slow melting during the summer.
Another issue is whether the salty seawater pumped to the surface will make the ice melt faster in spring. Salt lowers the freezing point of water, so it might. But when ice crystals form, most of the salt gets pushed out of them. There are early signs that the salty brine that is then formed drops through the ice, creating small channels. These may help meltwater drain away in spring, leaving bright bare ice instead of pools of dark water on the surface....
....MUCH MORE
Fortunately for the taxpayers a lot of the research and modeling can be done at the University of Bristol on their fancy, newly installed supercomputer:Britain's Most Powerful Supercomputer And The Butterfly Effect Of Weather Modeling In the Cloud
Great name.
Isambard Kingdom Brunel may be the greatest engineer of all time and the second greatest Briton of all time, trailing Winston Churchill. (Æthelred II did not make the list)....
