METHANE IN THE ARCTIC OCEAN
By Peter Wadhams London: Allen Lane, 2016
Why is the Arctic warming faster than the rest of the world? One explanation refers to the release of methane from permafrost— frozen soil. Methane retains heat vastly more than carbon dioxide, the greenhouse gas that we worry about most. Con - siderable research has been done on the rising temperatures of Arctic soil, especially in Siberia, a large part of the world’s carbon is located. However, there is also permafrost at the bottom of the Arctic ocean, whence comes much of the methane now being emitted. ¹
Methane has been escaping from the Arctic Ocean for thousands of years, and not enough research has been done yet to predict the duration of this process. Some say we have hundreds of years to solve the problem, while others say that it is happening quickly and may result in a few big explosions that push us past the tipping point toward calamity.
Apparently, large quantities of methane are being held down by an undersea permafrost “lid” that can perforate and release plumes of methane. Where the ocean is deep, this methane is absorbed without reaching the surface or the atmosphere. But the East Siberia Sea is extremely shallow, and there one can see plumes of methane bubbling to the surface, where it can be set on fire. (Indeed, it would be preferable to burn it all than let it escape as gas, since the product of burning it is CO2, which retains heat less than methane.)
Other studies report that much of the methane is coming from the undersea permafrost itself. Yet another recent study asserts that most of these plumes contain methane from a single large reservoir under the Laptev Sea. ²
Finally, a new report shows that the amount of methane being released at any moment is determined by the moon! The moon controls tides, and when the tide is high, the extra water holds the undersea gas down, while low tide reduces the pressure so that more methane is released. ³ The authors of this paper speculate as to whether the extra ocean depths that will result from global warming will have one beneficial side effect: limiting methane reduction. If so, this may help to offset what in other respects will be catastrophic.
Published a few years ago and slighted by climate science opinion makers, the media and policy makers, A Farewell to Ice is now coming into its own under the pressure of Arctic change. Peter Wadhams is the pre-eminent specialist on sea ice. This book is based on a career’s worth of Arctic and Antarctic ice observation, including more than fifty voyages on icebreakers in the ice and in nuclear-powered submarines under it. For this reviewer the chief takeaway is the potential for a release of methane from the coastal Arctic seabed, a release in volume and rate that may overwhelm the human effort to avert catastrophic climate change.
Wadhams, who teaches at the University of Turin, writes fluently and is a pleasure to read. His subject matter is complex but always of interest. In what amounts to a crash course on polar ocean and climate studies he introduces us to sea ice, the cycle of ice ages, workings of the greenhouse effect, the death spiral of Arctic sea ice, and effects of its loss on the weather, on the Gulf Stream and deep ocean currents and on the state and future of the planet. The book ends with a heartfelt discussion of what is to be done.
In Wadhams’s view there’s not a lot of choice. Mindless use of technology is serving to wreck the Earth’s ability to support life. Humanity has great difficulty in foregoing the comforts and conveniences of a fossil-fuelled existence. The Paris Agreement is a great step forward, but its purposes cannot be achieved by emission cuts alone. Mindful technology is what’s required.
This means carbon capture and sequestration (CCS), which is the development and employment of means to extract carbon dioxide from the air, to reduce the gaseous carbon to solid form and to bury it forever. A formidably complex and expensive process that is now being tested on Vancouver Island and elsewhere, CCS may offer a means to contain global warming and the climate change that comes from it. But it is certain to take time.
Wadhams therefore favours interim reliance on solar radiation management ( SRM) technology, which is even further from deployment than CCS. The idea here is to lower the surface temperature of the Earth by injecting sulphur particles into the stratosphere to back - scatter the sun’s rays and thus contain global warming for the time required to bring carbon capture to fruition.
These proposals for collective action offer a reasonable but incomplete response to the dire straits we are in. They prompt the question of where the motivation will come from for societies and governments to contain their desire for fossil-fuel benefits, to control the fossil-fuel incontinence that drives global warming and constrains timely decarbonization? They also encourage people to give up on the cessation of greenhouse gas emission. After all, if the Earth can be cooled, why worry about fossil-fuel use now?
Some of the motivation we need for a new approach to decarbonization may come from chapter nine. It deals with methane, a greenhouse gas that’s at least twenty times more potent than carbon dioxide and is now arising in abundance from permafrost under the shallow coastal waters of the Arctic Ocean, principally from the continental shelves adjoining Siberia.
As Wadhams explains, anthropogenic global warming has produced a feedback effect since about 2005. The effect starts when the atmosphere gets hot enough to melt Arctic sea-ice cover in summer. It continues as the retreat of the ice reveals more and more open water, which allows the sun to warm the sea, which raises the temperature of the frozen seabed, which
serves to release ancient methane into the atmosphere, which amplifies global warming, and around we go again. The shelf in the East Siberian Sea is estimated to hold 400 gigatonnes (Gt) of methane. If 50 Gt is released in a decade of sea-ice loss between 2015 and 2025, Wadhams calculates, the global temperature rise from this pulse of methane from this one Arctic area could be 0.6 degrees C by 2040.
A global catastrophe is taking shape in the Siberian offshore. Techno - logical responses are surely to be pursued. The same applies to efforts for consensus on the severity and imminence of the threat arising from terrestrial permafrost thaw as well as seaice melt. But how are we to apply our technological ingenuity in time to prevent runaway warming? How might we overcome our fossil-fuel incontinence?
Where Canada is concerned, we might begin by establishing a NorthSouth discourse that encourages shared knowledge of the situation we face. This means a sharing between the great southern majority with all its capabilities and detached appreciation of Nature, and Canada’s Arctic and northern Indigenous peoples whose traditional knowledge favours respect for and up-close understanding of the natural environment from within. SRM and CCS may be required of Canada as a whole, but we in the deep south will not achieve them without taking on Indigenous traditional knowledge that gives us attachment and emotion in caring for our milieu. There’s missing motivation to be had here.