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woensdag 21 september 2016

Arctic sea ice is in big trouble.

Arctic Expert on Sea Ice: We Could "Reach Zero" Within Two Years

Wednesday, 21 September 2016 00:00 By Dahr Jamail, Truthout | Interview
Dr. Peter Wadhams has conducted more than 50 trips to the Arctic, including exploring the Arctic sea ice from below in a submarine. (Photo: Peter Wadhams)Dr. Peter Wadhams has conducted more than 50 trips to the Arctic, including exploring the Arctic sea ice from below in a submarine. (Photo: Peter Wadhams)
Arctic sea ice is in big trouble.
This is bad news for multiple reasons, the primary one being that Arctic sea ice helps keep the polar regions cool along with working to moderate the entire global climate.
"Sea ice has a bright surface; 80 percent of the sunlight that strikes it is reflected back into space," explains the National Snow and Ice Data Center's website. "As sea ice melts in the summer, it exposes the dark ocean surface. Instead of reflecting 80 percent of the sunlight, the ocean absorbs 90 percent of the sunlight. The oceans heat up, and Arctic temperatures rise further."
This also explains the most well-known -- and what is most likely the most important -- climate-related positive feedback loop, which has already spun out of control. 
When it comes to anthropogenic climate disruption (ACD), the Arctic is the proverbial canary in the coalmine. And if Arctic sea ice expert Dr. Peter Wadhams is right, that canary will likely be gone within two years. This would be the first time in more than 10,000 years that the Arctic sea ice has disappeared.
Dr. Wadhams has been a professor of ocean physics at Cambridge University since 2001 and was the director of the Scott Polar Institute there from 1987 to 1992. He has also made more than 50 trips to the Arctic. Dr. Wadhams was one of the very first scientists to show that the icecap that once covered the entire Arctic Ocean was starting to both grow thinner and shrink in area.
Dr. Wadhams recently published A Farewell to Ice, a book that explains, in depth, how the sea ice is vanishing at an alarming rate, and details the dire consequences for the Earth if the sea ice continues to disappear at these rates.
His work and recent book could not be more relevant, as it has been a record hot year for the planet -- and Arctic sea ice is, by most measurements, on pace to reach its second-lowest annual minimum, with open water gaps appearing even near the North Pole.
Current tracking shows that the sea ice is following a steady downward trajectory of melting, and there is no evidence to indicate that this trend will not continue. This makes sense, given that recently released NASA data show that August was the hottest August since record-keeping began, and it tied July for the warmest month ever recorded.
Truthout interviewed Dr. Wadhams to provide a more in-depth perspective about what it means for the planet to lose Arctic sea ice. 
Truthout: Numerous people have predicted the vanishing of the Arctic sea ice in summer, including a US Navy study that predicted it by this summer, but they've all been too early in their predictions. Why do you feel confident about predicting that summer Arctic sea ice will disappear in either 2017 or 2018 at the latest?
Dr. Peter Wadhams: I don't feel confident -- it's simply that this is the trend shown by the sea ice volume in recent years, and since that volume is now quite small, it ought to reach zero within one to two more years. But, of course, something could happen to change that.
How does the rate of Arctic sea ice loss now compare to, say, 20 years ago?
The rate of change of area (averaged over the year) has increased from 3 percent per decade to 8 percent per decade.
What are the immediate and most dramatic regional impacts of the loss of the summer Arctic sea ice on the Arctic?
First, the loss from the shallow shelf areas north of Siberia is dangerous because it encourages emission of methane from the sea bed as the offshore permafrost melts. Secondly, the loss from Baffin Bay and East Greenland in summer encourages warm winds over the Greenland ice sheet, which cause ice-sheet melt and accelerated sea level rise.
How will global climate be impacted by the loss of the summer Arctic sea ice?
The main effect is global albedo reduction. [Albedo, a critically important element of ACD, is the Earth's measure of reflectivity. When Earth's albedo increases, more sunlight and solar radiation is reflected back into space.] This has been calculated as equivalent to adding 25 percent to the warming effect of the greenhouse gases alone. Albedo reduction due to parallel snow area loss [less snow means less albedo/reflectivity, which means more solar radiation and heat are absorbed by Earth] adds another 25 percent.
We have reported quite extensively on the threat of increasing amounts of methane being released as permafrost melts. Why should people be concerned about methane releases in the Arctic, and the fact that these are increasing?
We have modeled what would happen if the rate of emission increased radically to be equivalent to a 50-gigaton pulse (predicted by the Russian scientists who work on offshore methane). It would give a 0.6C boost to global warming immediately -- which is a very large figure.
On August 18 a massive luxury cruise ship departed Seward, Alaska to head up to the Arctic, where it will cruise across the coast en route to New York City. Given your expertise on the Arctic, please share your thoughts about the fact that a company is now exploiting the open ocean there for profit, and already has plans for another cruise given that the first one sold out.
It's very dangerous, as the cruise ship has no ice protection. I was on an NAS[National Academy of Sciences] panel, which considered the implications of an oil spill in Alaskan coastal waters. In our report, the sinking of a cruise ship was one of the most serious scenarios, since it creates an oil slick and the humanitarian problem of how to deal with perhaps 2,000 passengers in a region with no facilities at all.
You have been outspoken and frank about how rapidly the situation is changing in the Arctic. Why do you suppose more scientists aren't being as outspoken in their alarm and concern over what is happening there and what it means to the planet?
Career considerations: If they speak out, they fear that it will upset their promotion prospects, so they keep their heads down.
Similarly, why do you feel most major media tend to shy away from reporting accurately on how far along we already are regarding anthropogenic climate disruption?
Often the proprietor has a vested interest in the continuation of fossil fuel use, e.g. Rupert Murdoch has big interests in the Australian coal industry.
My reportage on climate disruption presupposes that many of our readers understand it cannot be stopped at this point... that we can, at best, hope to mitigate the impacts somewhat. Do you propose any solutions for what can be done along those lines, both on a personal as well as a governmental level?
In my book, I acknowledge that nothing we can do to reduce CO2 emissions is enough, because there is already more than enough CO2 in the atmosphere to cause a 2C warming. [2C warming above preindustrial baseline temperatures has been an internationally agreed-upon political goal of the maximum warming that can be allowed. Global governments agreed in Paris in December 2016 that 1.5C should be the maximum warming allowed; however, we are already very near to that limit today, just 10 months after the Paris climate talks.] The only things we can do are to, first, put a sticking plaster on warming by use of geoengineering techniques to reflect more radiation -- for example, marine cloud brightening -- and second, to solve the problem properly by spending a lot of thought and energy developing a cost-effective method of direct air capture of CO2 from the atmosphere.
Any final thoughts you'd like to leave with our readers?
As a final point, sea ice retreat from the Greenland Sea has prevented the formation of chimneys -- deep cylinders through which surface water sinks to great depths. This slows the thermohaline circulation [the movement of seawater in a pattern of flow dependent on variations in temperature, which give rise to changes in salt content and hence in density], which will result in cooling -- or slower warming -- of the Northwestern Atlantic coastline (e.g. Britain) and faster warming of the tropical Atlantic (e.g. more intense hurricanes).
The latest research echoes Dr. Wadhams' concerns.
Earlier this year, NASA provided data showing that the wintertime Arctic sea ice extent had hit a record low.
Rapid loss of sea ice continued until May, but then slowed enough that the previous summertime sea ice minimum record was not broken.
That said, Walt Meier, a sea ice scientist at NASA's Goddard Space Flight Center in Maryland announced this August: "Even when it's likely that we won't have a record low, the sea ice is not showing any kind of recovery. It's still in a continued decline over the long term. A decade ago, this year's sea ice extent would have set a new record low and by a fair amount. Now, we're kind of used to these low levels of sea ice -- it's the new normal."
Thus, as Dr. Wadhams warns, if the "new normal" continues at the current trajectory, within two years, the Earth is going to look very, very different.
Copyright, Truthout. May not be reprinted without permission.

DAHR JAMAIL

Dahr Jamail, a Truthout staff reporter, is the author of The Will to Resist: Soldiers Who Refuse to Fight in Iraq and Afghanistan, (Haymarket Books, 2009), and Beyond the Green Zone: Dispatches From an Unembedded Journalist in Occupied Iraq (Haymarket Books, 2007). Jamail reported from Iraq for more than a year, as well as from Lebanon, Syria, Jordan and Turkey over the last 10 years, and has won the Martha Gellhorn Award for Investigative Journalism, among other awards.
His third book, The Mass Destruction of Iraq: Why It Is Happening, and Who Is Responsible, co-written with William Rivers Pitt, is available now on Amazon. 
Dahr Jamail is the author of the forthcoming book, The End of Ice, forthcoming from The New Press. He lives and works in Washington State.

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