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Arctic thaw – carry on regardless?

 

Svalbard ice (Irene Quaile)

Svalbard ice (Irene Quaile)

When a colleague who has a lot of sympathy for those who do NOT accept that humans are responsible for global warming drew attention to the fact that this had been the hottest June on record, following hard on the hottest May, I must admit I was temporarily put of my guard. Aha, I thought. Is he finally getting the message? Alas, the answer is no. There is a small minority of people that still argues – for whatever reason – that natural variation could be responsible for all this, while acknowledging the record concentration of CO2 in the atmosphere. “And all that stuff”. Hm.

Date

July 24, 2014 | 2:16 pm

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Emperor Penguins in Distress

Penguins galore, Thanks to the International Polar Foundation for the pic from Antarctica, December 2012,

Penguins galore?  Thanks to the International Polar Foundation for the pic from Antarctica, 2012,

It has been a busy week for me here at DW, and unfortunately I was not able to do justice to the latest research on the likely fate of the Emperors down at the far south of the planet in the form of some interviews or a detailed article. Before I head off to a seminar tomorrow, I want to make sure the Ice Blog does not neglect our majestic friends in the Antarctic. Fortunately, Tim Radford from the Climate News Network has summed up the story: ” Loss of Antarctic sea ice through climate change threatens the emperor penguin’s habit to such an extent that scientists say it should now be made an iconic symbol – like China’s endangered giant panda – of the wildlife conservation movement” . Thanks Tim, Alex and all at the Climate News Network who keep us up-to-date on so many important climate issues. Thanks also to Dave Walsh for alerting to me to this study which, I am pleased to say, made its way into a lot of media outlets, if only briefly. Thanks also to Dave for the Belgian International Polar Foundation picture.

Allow me to quote at length from Tim’s summary:

“Global warming will this century take its toll of Antarctica’s most regal predator, the emperor penguin. There are now 45 colonies of this wonderful bird, but by 2100 the populations of two-thirds of these colonies will have fallen by half or more.

Stéphanie Jenouvrier, a biologist at the Woods Hole Oceanographic Institution in the US, and colleagues from France and the Netherlands report in Nature Climate Change that changes in the extent and thickness of sea ice will create serious problems for a flightless, streamlined , survival machine that can live and even breed at minus 40°C, trek across 120 kilometres of ice, and dive to depths of more than 500 metres. The researchers took all the data from 50 years of intensive observation of one colony in Terre Adélie and used climate models to project a future for the other 44 colonies known in the Antarctic.

Decisive factor

They found that the decisive factor in emperor penguin survival was the sea ice. If the seas warmed and there wasn’t enough ice, then that affected the levels of krill in the southern ocean, and therefore reduced the available prey. It also made the penguins more vulnerable to other predators. If the opposite happened and there was too much sea ice, then foraging trips took longer and penguin chicks were less likely to survive.

Aptenodytes forsteri – the Linnean name for the emperor – is not in trouble yet, and its numbers may even grow in the years up to 2050. But this growth won’t last, and decline is likely everywhere. Climate change has already begun to affect penguin species much further north, in Argentina, by taking toll of young chicks.

Emperor penguins stand out against the ice - even seen from space!

Emperor penguins stand out against the ice – even seen from space! Picture by Paul Ponganis, NSF

Endangered class

For different reasons, the average rise in global temperatures forecast by the Intergovernmental Panel on Climate Change (IPCC) could push the emperor into the endangered class.

“If sea ice declines at the rates projected by the IPCC climate models, and continues to influence emperor penguins as it did in the second half of the 20th century in Terre Adélie, at least two-thirds of the colonies are projected to have declined by greater than 50% from their current size by 2100,” Dr Jenouvrier said. “None of the colonies, even the southernmost locations in the Ross Sea, will provide a viable refuge by the end of the 21st century.”

The researchers end their paper by arguing that the emperor should – like the giant panda in China – become an icon for the conservation movement. They conclude: “We propose that the emperor penguin is fully deserving of Endangered status due to climate change, and can act as an iconic example of a new global conservation paradigm for species threatened by future climate change.” – Climate News Network.

– Yet another worrying piece of evidence on how human-made climate change is threatening the biodiversity of the planet, even in that “last bastion” of the Antarctic.  The question is whether those iconic examples of species under threat from climate change like the penguins and their northern counterparts the polar bears are doomed to disappearance or whether their plight can really prompt the kind of lifestyle change and political and economic turnaround we need to put the brakes on climate change. I wish I could say I felt optimistic and had heard more than a lot of sympathetic “awwww”s in response to this latest distressing piece of penguin news.

See also:

West Antarctic Ice Sheet collapse unstoppable

Climate Risk to Icy East Antarctica

Ice Blog Post: Will the Antarctic share the Arctic’s Fate?

 

 

Date

July 3, 2014 | 2:10 pm

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Polar Ice at UN Bonn Climate Talks

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

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

The delegates to the UN climate meeting currently taking place here in Bonn are receiving an urgent appeal from polar scientists to cut emissions to slow polar ice melt and give low-lying coastal regions more time to adapt to rising sea levels.

I was very interested to hear about a side-event being held here this evening, at which the authors of this year’s key studies on developments in the Antarctic will be explaining the connections between melting polar ice and climate change impacts like rising seas, affecting regions as diverse as small island states, Bangladesh or Florida in the USA.

I interviewed Anders Levermann from PIK, the Potsdam Institute for Climate Impacts Research and Pam Pearson, Director of ICCI, the International Cryosphere Climate Initiative, both in Bonn for the event.

The ICCI decided to bring the cryosphere into the Bonn talks to sensitize delegates to the dramatic developments in the Antarctic in particular, says Pearson. Ice Blog readers (and I was so delighted to hear Pam herself is one!) will remember posts earlier this year on melting in the East and West Antarctic. I also covered these in articles for DW. The shocking thing is that the Antarctic, even East Antarctica, which was until relatively recently considered so cold it had to be safe from global warming, is already being affected by climate change. The papers on the West Antarctic even described the melt trend as “irreversible”.

We have entered an era of irreversible climate change”.

Today, Anders Levermann, author of the East Antarctic paper and one of the world’s leading Antarctic researchers, told me “we have entered a new era of climate change, witnessed the tipping of the West Antarctic ice sheet, and this is irreversible”.

That should really shock people into action, you would think. But climate negotiations are moving, as one of the experts said to me at the meeting “at a glacial pace”. As we can see in Antarctica, though, and Greenland and other regions, those glaciers are speeding up. Maybe there is hope for the climate talks yet!

The announcements by the USA and China on possible emissions cuts have brought a new “buzz” to the Bonn conference. The fact that the key emitters could finally be getting the message and preparing to move, with the impacts of climate change hitting their own countries, has to be a positive signal. Pearson confirmed to me that people in the sunshine state of Florida, where she lives, had become more aware of the importance of melting ice caps with increasing floods and storms.

As Levermann says, Antarctica and Greenland have a huge potential to raise sea level further than previously anticipated. He was lead author on the IPCC report chapter on sea level rise. The latest IPCC report factored in some of the likely impacts from melting ice in these regions for the first time. Of course the latest research was not yet included. For the 21st century forecast, this will not make a lot of difference, says Levermann. But the fact that this irreversible Antarctic melt is now underway will make a big difference to coming generations.

There are those who dispute whether the warming of the ocean, which is causing the Antarctic melt (unlike the surface melt on Greenland) is man-made. Levermann does not rule out natural variation as a possible influence. But ultimately, he says, that is irrelevant. Greenhouse gas emissions and so human interference are warming the planet, and any further warming, whatever the cause, will speed up ice melt. So cutting emissions is the way to slow it down and, Pearson adds, gives people time to adapt to rising seas.

The combination of models based on the principles of physics, using a higher resolution than ever before, and evidence from ice cores showing what happened in the past, make for a high degree of certainty about these ice developments, says Levermann.

“The level of warming will determine the rate with which we discharge West Antarctica, and we can still prevent the tipping of East Antarctica”, the cryosphere experts told us here in Bonn.

That is a huge responsibility. Here’s hoping the message will make it into the hearts and minds of those negotiating the future of the earth’s climate and the governments they represent.

Date

June 13, 2014 | 2:34 pm

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Keeping Greenland in focus

Greenland ice wall

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.”

IMG_1172

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)

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.

 

Date

May 23, 2014 | 2:39 pm

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Cryosphere in Crisis?

Melting...

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.

P1010041

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?

 

 

Date

May 14, 2014 | 2:46 pm

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