The Greenland ice sheet, photographed 2009 (I.Quaile)

Two interesting publications relating to Greenland caught my eye over the past few days. But it has not proved easy to get them onto the international news agenda. Given the huge importance of the Greenland ice sheet to the planet’s future, this is frustrating to say the least. Fortunately there is the Ice Blog.

The first research relates to a study about the role of ash from fires in bringing about large-scale surface melting. The other predicts Greenland will be a far greater contributor to sea rise than expected.

Let me start with the latter, published in Nature Geoscience. Scientists from the University of California – Irvine and NASA glaciologists have found previously uncharted long deep valleys under the Greenland Ice Sheet. Since these bedrock canyons are well below sea level, they are much more vulnerable to warm ocean waters than previously thought. When warmer Atlantic water hits the fronts of hundreds of glaciers, the edges will erode much further than previously assumed, releasing far greater amounts of water.

Ice melt from the subcontinent has already accelerated, as warmer marine currents have migrated north, the authors say. Older models predicted that once higher ground was reached in a few years, the ocean-induced melting would halt. Greenland’s frozen mass would stop shrinking, and its effect on higher sea waters would be curtailed.

“That turns out to be incorrect. The glaciers of Greenland are likely to retreat faster and farther inland than anticipated – and for much longer – according to this very different topography we’ve discovered beneath the ice,” says lead author Mathieu Morlighem, a UC Irvine associate project scientist, on the university website. “This has major implications, because the glacier melt will contribute much more to rising seas around the globe.”

Icebergs from a Greenland glacier melt on.. (I.Quaile)

To obtain the results, Morlighem developed what he says is a breakthrough method that for the first time offers a comprehensive view of Greenland’s entire periphery. It’s nearly impossible to accurately survey at ground level the subcontinent’s rugged, rocky subsurface, which descends as much as 3 miles beneath the thick ice cap.

Since the 1970s, limited ice thickness data has been collected via radar pinging of the boundary between the ice and the bedrock. Along the coastline, though, rough surface ice and pockets of water cluttered the radar sounding, so large swaths of the bed remained invisible.

Measurements of Greenland’s topography have tripled since 2009, thanks to NASA Operation IceBridge flights. But Morlighem says he quickly realized that while that data provided a fuller picture than the earlier radar readings, there were still major gaps between the flight lines.

To reveal the full subterranean landscape, he designed a novel “mass conservation algorithm” that combined the previous ice thickness measurements with information on the velocity and direction of its movement and estimates of snowfall and surface melt.

The difference was dramatic, says Morlighem. What appeared to be shallow glaciers at the very edges of Greenland are actually long, deep fingers stretching more than 100 kilometers (almost 65 miles) inland.

“We anticipate that these results will have a profound and transforming impact on computer models of ice sheet evolution in Greenland in a warming climate,” the researchers conclude.

“Operation IceBridge vastly improved our knowledge of bed topography beneath the Greenland Ice Sheet,” said co-author Eric Rignot of UC Irvine and NASA’s Jet Propulsion Laboratory. “This new study takes a quantum leap at filling the remaining, critical data gaps on the map.”

Other co-authors are Jeremie Mouginot of UC Irvine and Helene Seroussi and Eric Larour of JPL. Funding was provided by NASA.

This is the same team that reported on accelerated glacial melt in West Antarctica, as discussed in an earlier Ice Blog post.  Together, the papers “suggest that the globe’s ice sheets will contribute far more to sea level rise than current projections show,” Rignot said.

Indeed. These scientists are telling us the IPCC forecasts were way too low. This could have huge consequences for coastal communities all around the globe.

Unfortunately, a lot of people (even those you would expect to know better) tend to mix up “Arctic” and “Antarctic”. It all goes into the category of “melting ice”, and they think they have heard it all before. What they still don’t realize is that this is something that concerns us all, and that these two polar areas are of huge significance to the world climate as a whole and global sea level. When those two Antarctic studies were released, there was a flurry of news coverage. The challenge for us journalists is how to follow this up and stop the attention curve from dropping.

Plodding on… (I.Quaile)

The other interesting piece of recent Greenland research was conducted by the Dartmouth College Thayer School of Engineering and the Desert Research Institute and reported in the Proceedings of the National Academy of

Sciences. It concludes that ash from Northern hemisphere forest fires combined with rising temperatures to cause large-scale surface melting of the Greenland ice sheet in 1889 and 2012.

The researchers say their findings contradict conventional thinking that the melting was driven by warming alone.

The findings suggest that continued climate change will result in nearly annual widespread melting of the ice sheet’s surface by the year 2100.

Melting in the dry snow region does not contribute to sea level rise, but when the meltwater percolates into the snowpack and refreezes, the surface is less reflective. This reduces the albedo.

Let me give the (almost) last word to the study’s lead author Kaitlin Keegan.

“With both the frequency of forest fires and warmer temperatures predicted to increase with climate change, widespread melt events are likely to happen much more frequently in the future”.

It figures.

Ice in shadow on an Arctic summer night (I.Quaile)

When a meeting of the Senior Arctic Officials of the Arctic Council scheduled to take place in Canada in June was cancelled, one couldn’t help assuming the political standoff between Russia, on the one side, and the US and other European partners on the other over Ukraine must have played a role. The Arctic Council Secretariat, based in Tromsoe in Norway, was keen to play down any political implications. In response to my inquiry, I was told the meeting had been rescheduled in form of teleconferences and written exchanges, and various meetings of Council working groups and task forces were going ahead in the coming weeks in Canada and in other Arctic Council member states. Business as usual? When Canada, which currently holds the chair of the Arctic Council, boycotted a working meeting of the organization planned for April in Moscow, Environment Minister Leona Aglukkaq called it a “principled stand” against Russian actions in Ukraine.

On other levels, the political repercussions of the Ukraine crisis for the Arctic are undisputed. A statement from the US State Department reads:

“Given Russia’s ongoing violation of Ukraine’s sovereignty and territorial integrity, the US government has taken a number of actions, to include curtailing official government-to-government contacts and meetings with the Russian Federation on a case-by-case basis”.

And that includes Arctic-related events. In Alaska Dispatch, Yereth Rosen reports the withdrawal of State Department funding for a hazard-reduction workshop planned for June between Russian scientists and their US counterparts. He also notes the head of Russia’s emergency services failed to show up at an international meeting in the US state last month.

With the West looking to broaden sanctions against Russia because of the Ukraine dispute, relations between the two factions are bound to be strained in a region where climate change has set off a highly competitive race for oil, gas and other resources.

Defending Arctic interests

While careful to secure their own business interests, the USA plans to block exports of oil and gas technology for new projects run by Russian state-controlled companies, if the Kremlin interferes with the Presidential elections planned to take place in Ukraine on May 25^th.

“Depriving Rosneft and Gazprom of the most modern technology would be a significant setback for their ambitions in the areas that are the future of the Russian industry, including the Arctic”, writes Ed Crooks in the Financial Times of May 14^th.

Well before the annexation of Crimea, Moscow made no bones about its intention to defend its energy and other economic interests in the Arctic region. President Putin has made it a strategic priority, re-establishing Soviet airfields and ports and preparing a strategic military command to be set up in the Russian Arctic by the end of this year.

Melting ice, easier access, disputed claims (I.Quaile)

Territorial claims

Russia, the only non-NATO coastal Arctic state, holds more Arctic territory than any of the other seven Arctic nations. It also lays claim before the UN Commission on the Limits of the Continental Shelf to an extension of its own shelf, including the huge seabed area of the Lomonosov Ridge. Other countries that have claims on the Arctic seabed include Canada, Denmark,  Norway, and the United States.

In March this year, the Commission approved Russia’s longstanding claim to 52,000 square kilometers of seabed in the Sea of Okhotsk in the Pacific Ocean, believed to be rich in oil and gas. At the time, the Russian Minister of Natural Resources and Environment Sergey Donskoy told journalists the UN decision was also “the first step in our Arctic applications, which will be ready in the near future.”

The Times Moscow correspondent Ben Hoyle responded with the headline “Russia’s legal land grab is dress rehearsal for Arctic showdown”.

A matter for NATO?

Former US Secretary of State Hillary Clinton earlier this year called for the USA and Canada to take up a united stand in response to Moscow’s military build-up in the Arctic .

According to the TTU online newsletter on defense and strategy, pressure is mounting on the Canadian prime minister Stephen Harper to abandon opposition to making the Arctic a part of NATO’s official agenda.

Harper would prefer to see the bilateral North American Aerospace Defense Command NORAD extended to forces on land and on sea. The defense experts say the Harper administration is at the same time using the Ukrainian conflict to re-gain geostrategic influence at a time where Russia is building up a strong maritime position in the Arctic.

The defense publication quotes international political risk research consultancy Polarisk Analytics however as saying extending NORAD’S powers would mean keeping up the old block mentality. That would not guarantee sufficient stability to attract private western investment in the Arctic.

Including the Arctic in NATO’s official agenda would provoke a counterproductive escalation, which could have a lasting destabilizing effect on Arctic cooperation and lead to confrontations, says Polarisk. They suggest the debate should be conducted within the Arctic Council. But so far, that has remained outside its mandate, focusing instead on environmental protection and health and safety.

Professor Lawson Brigham of the University of Alaska Fairbanks, former chairman of Arctic Council’s Arctic Marine Shipping Assessment, told Alaska Dispatch “There are enough environmental issues and enough people issues to keep us busy and keep us together”.

He said he hoped tensions would ease enough and US leaders would be “diplomatically adroit enough to pull off one of the goals articulated in White House recent Arctic Strategy implementation plan:  a 2016 “Presidential Arctic Summit”, attended by heads of Arctic nations to mark the Arctic Council’s 20^th anniversary.

First, let’s see how the next Arctic Council SAO meeting in Yellowknife, Canada this autumn works out. Given that the chair of the Council goes to the USA in 2015, it seems unlikely that the long shadow of the ongoing Ukrainian conflict will become shorter any time soon.

Melting…

You can’t  say the latest research results on the thinning of the West Antarctic ice sheet didn’t make the media. From the news agencies through the quality media and even publications not known for their detailed science or environment coverage – nearly all reported that two separate studies each independently come to the conclusion that parts of the West Antarctic ice sheet are already “collapsing”. They say this could result in a considerable sea level rise within the next century or two. This would have devastating consequences for low-lying coastal areas around the globe.

No-one can really say they didn’t know about this. For once, the Antarctic ice has made into the headlines of the mainstream media. This is the region people tend to think of as having “eternal ice”, where global warming will “not make much difference”. There are those who criticize the media for sensationalism or exaggeration by taking over the term “collapse” for a process which will still take hundreds to thousands of years. See for example Andrew Revkin’s post on Dot Earth (New York Times), (and an excellent response by Tom Yulsman in ImaGeo: (Discover Magazine). But, semantic discussions apart – as Yulsman puts it:

“On a human timescale, 200 years or more for the start of rapid disintegration is a very long time indeed. But on a geologic timescale, it is the blink of an eye. And that’s important to keep in mind too — that in a blazing flash, geologically speaking, we humans are managing to remake the life support systems of our entire planet. This is why I think today’s news may eventually be seen as having historic significance”. At any rate, he concludes “it is yet another clear sign that human-caused changes to the planet once regarded as theoretical are now very real”.

Indeed Tom. The question is: what are we going to do about it? Has it set the alarm bells ringing? Did anybody see a rash of reactions promising quick action on reducing emissions to mitigate climate change? If so, please point me in the right direction. So far, I haven’t seen any indication of anything other than business as usual.

The West Antarctic ice sheet contains so much ice that it would raise global sea level by three to four meters if it melted completely. As it sits on bedrock that is below sea level, it is considered particularly vulnerable to warming sea water. Until now, scientists assumed it would take thousands of years for the ice sheet to collapse completely. The two new studies indicate that could happen much faster – as early as 200 years from now or, at the most, 900. Both research teams, using different methods and looking at different parts of the ice sheet, conclude that the trend is probably unstoppable.

The NASA study published in “Geophysical Research Letters” uses data from satellites, planes, ships and measurements from the shelf ice to examine six large glaciers in the Amundsen Sea over the last 20 years. The second report, from the University of Washington published in the journal “Science,” uses computer models to study the Thwaites glacier. It is considered of particular importance because it acts as a type of “lynch pin”, holding back the rest of the ice sheet.

According to NASA researcher Eric Rignot, the glaciers in the Amundsen Sea sector of West Antarctica have “passed the point of no return.” He told journalists this would mean a sea level rise of at least  1.2 meters (3.93 feet) within the next 200 years.The University of Washington scientists worked out, using topographical maps, computer simulations and airborne radar, that the Thwaites glacier is also in an early stage of collapse. They expect it to disappear within several hundred years. That would raise sea levels by around 60 centimeters (23.62 inches). The NASA study showed that sea level rises of 1.2 meters are possible

The good news, according to author Ian Joughlin, is that while the word “collapse” implies a sudden change, the fastest scenario is 200 years, and the longest more than 1,000 years. The bad news, he adds, is that such a collapse may be inevitable: “Previously, when we saw thinning we didn’t necessarily know whether the glacier could slow down later, spontaneously or through some feedback,” Joughlin says. “In our model simulations it looks like all the feedbacks tend to point toward it actually accelerating over time. There’s no real stabilizing mechanism we can see.”

The latest IPCC report does not adequately factor ice loss from the West Antarctic ice sheet into its projections for global sea level rise, on account of a lack of data. These “will almost certainly be revised upwards,” according to Sridar Anandakrishnan from Pennsylvania State University at the presentation of the University of Washington study. The scientist was not involved in the research.

NASA glaciologist Rignot said he was taken aback by the speed of the changes. “We feel this is at the point where … the system is in a sort of chain reaction that is unstoppable,” he said.

Rignot also makes the key point that this development tells us not only about the area down at the South Pole, but about the whole climate system: “This system, whether Greenland or Antarctica, is changing on a faster time scale than we anticipated. We are discovering that every day.”

My last two blog posts have been about melting of the Greenland ice sheet and melting even in the East Antarctic, which is usually cited as the last bastion against ice-destroying climate change. We are subjecting our cryosphere to huge pressures and have set a “snowball” rolling, which is picking up momentum and will ultimately carry masses of ice into a rising ocean.

Rignot says even drastic measures to cut greenhouse gas emissions could not prevent the collapse of the West Antarctic ice sheet. That is a terribly depressing thought.  I would like to think this will prove wrong. But if there is any chance to avert that disaster and preserve our polar ice for thousands of years rather than just a few hundred, surely the time for action is now?

Greenland ice sheet (Photo I.Quaile) – melting too fast!

And does it ultimately make any difference? Scientists from the University of Washington (UW) have published a paper in Nature estimating that up to half of the recent warming in Greenland and surrounding areas may be due to climate variations that originate in the tropical Pacific and are not connected with the overall warming of the planet. You can just hear the “I told you so”, from the climate skeptics. “Still”, the UW scientists add, “at least half the warming remains attributable to global warming caused by rising carbon dioxide emissions”.

With all due respect to the scientists who do this essential research – I repeatedly find myself wondering how we can talk about “natural” climate variations at all any more,  given that we have changed the parameters so much you could argue none of it is really without human impacts. Does natural fluctuation not act differently if you are starting from completely different base data, brought about by man-made warming through greenhouse gas emissions?

Greenland and parts of neighboring Canada have experienced some of the most extreme warming since 1979, at a rate of about 1 degree Celsius per decade, or twice the global average, the scientists say. “We need to understand why in the last 30 years global warming is not uniform”, says first author Qinghua Ding, a UW atmospheric research scientist. “Superimposed on this global average warming are some regional features that need to be explained”.

Longer enforced holidays for sled dogs? (Quaile, Greenland)

The study uses both observations and advanced computer models. It comes to the conclusion that a warmer western tropical Pacific Ocean has caused atmospheric changes over the North Atlantic that have warmed the surface by about half a degree per decade since 1970. “The pattern of the changes in the tropical Pacific that are responsible for remarkable atmospheric circulation changes and warming in Greenland and the Canadian Arctic are consistent with what we would call natural variability”, says co-author David Battisti, a UW professor of atmospheric sciences.

Of course there will always be natural variability in the course of the seasons and changing meteorological conditions.  But in many of the fastest—warming areas on earth, co—author of the new study  John “Mike” Wallace, also professor at UW, says global warming and natural variations combine to create a “perfect storm” for warming.

The scientists attribute the natural variations in their study to an “unusually warm western tropical Pacific, near Papua New Guinea. Sind the mid-1990s the water surface there has been about 0.3 degrees hotter than normal. Computer models show this affects the regional air pressure, setting off a stationary wave in the atmosphere that arcs in a great circle from the tropical Pacific toward Greenland before turning back over the Atlantic”.  Wallace says there are warm spots where the air has been pushed down, and cold spots where the air has been pulled up. And Greenland, he explains, is in one of the warm spots”.

This and other research by these scientists has documented the existence of decades-long climate variations in the Pacific Ocean which resemble the better known shorter-range El Nino variations. Other studies have indicated that waves starting in the same place in the tropical Pacific but radiating southward are warming West Antarctica and melting the Pine Island Glacier, which has been the subject here on the Ice Blog before.

The experts describe this natural variation as “unpredictable”, whereas the half of the warming in Greenland from the “forcing of climate by anthropogenic greenhouse gases” is “predictable”.

So what do we learn from all of this? One thing is clear. It does NOT change the threat to Greenland’s ice from our man-made warming: “Nothing we have found challenges the idea that globally, glaciers are reatreating, says Battisti. “Ice appears to be exquisitely sensitive to the buildup of greenhouse gases, more than we ever would have thought”, says his colleague Wallace.

Ultimately, the researchers say, natural variations could either accelerate or decelerate the melting rate of Greenland’s glaciers in coming decades. But, “in the long run, the human induced component is likely to prevail”.

So don’t let anybody use this as an excuse to talk down the need to cut emissions in a big way asap.

… And the ice continues to melt. (Pic: I. Quaile, Greenland)

While the Arctic is melting twice as fast as the rest of the planet, and protests continue against the race for oil at huge risk to the sensitive environment,  the icy regions around the south pole were long considered immune to climate change. But melting glaciers on the Antarctic Peninsula in recent years sparked doubts in the scientific community about just how stable the western region of Antarctica really is. Earlier this year, I wrote an article on the irreversible melt of the Pine Island glacier on western Antarctica. The huge iceberg that broke off last November has been in the news again, heading for the open sea.

Only the huge icy vastness of Eastern Antarctica still appeared to be safe from the perils of a warming climate. Now experts from Germany’s Potsdam Institute for Climate Impact Research (PIK) have published findings indicating that this too might no longer be the case. In a study published in “Nature Climate Change“, they write that the melting of just a small volume of ice on the East Antarctic coast could ultimately trigger a discharge of ice into the ocean which would result in unstoppable sea-level rise. They are talking about tomorrow or the next decade. Still, the prospect of more irreversible thawing in the Antarctic is a very worrying one.
“Previously, only the West Antarctic was thought to be unstable. Now we know that the eastern region, which is ten times bigger, could also be at risk”, says Anders Levermann, co-author of the study. The findings are based on computer simulations which make use of new, improved data from the ground beneath the ice sheet.PIK scientist Levermann was one of the lead authors of the sea-level section in the latest IPCC report.
“The Wilkes Basin in East Antarctic is like a bottle that is tilted”, says Matthias Mengel, lead author of the new study.”If you take out the cork, the contents will spill out”. At the moment, the “cork” is formed by a rim of ice at the coast. If that were to melt, the huge quantities of ice it holds back could shift and flow into the ocean, raising sea levels by three to four meters. Although air temperatures over Antarctica are still very low, warmer ocean currents could cause the ice along the coast to melt.

Warming oceans: Melting from below (Photo: I.Quaile)

So far, there are no signs of warmer water of this sort heading for the Wilkes Basin. Some simulations suggest though that the conditions necessary for the “cork” to melt could arise within the next 200 years. Even then, the scientists say it would take around 2000 years for sea level to rise by one meter.
According to the simulations, it would take 5,000 to 10,000 years for all the ice in the affected region to melt completely. “But once this has started, the discharge will continue non-stop until the whole basin is empty”, says Mengel. “This is the basic problem here. By continuing to emit more and more greenhouse gases, we could well be triggering reactions today that we will not be able to stop in the future. ” Indeed.
The IPCC report predicts a global sea-level rise of up to 16 centimeters this century. As this could already have devastating impacts on many coastal areas around the globe, any additional factor is of key importance to the calculations. “We have presumably overestimated the stability of East Antarctica”, says Levermann. Even the slightest further increase in sea level could aggravate flooding risks for coastal cities like New York, Tokyo or Mumbai.
At the moment, the largest contribution to Antarctic ice loss and rising sea levels comes from the Pine-Island glacier in West Antarctica. As I mentioned at the start, a huge iceberg, which broke off from the glacier last year, is currently floating into the open waters of the Southern Ocean. French glaciologist Gael Durand from Grenoble University told me in an interview the huge glacier had already reached a point where its continued melting is irreversible, regardless of air temperature or ocean conditions.