Search Results for Tag: ice
Melting permafrost eroding Siberian coasts
Rising summer temperatures and dwindling Arctic sea ice are eroding the cliffs of Eastern Siberia at an increasing pace. Scientists from AWI, the German Alfred Wegener Institute and the Helmholtz Centre for Polar and Marine Research have been evaluating data and aerial photographs of the coastal regions from the last 40 years. As the sea ice recedes more and more from year to year, the cliffs are being undermined by waves. At the same time, the land surface is beginning to sink.
The research documents warming summers. While the temperatures during the period looked at were higher than zero degrees Celsius on an average of 110 days per year, the scientists counted a total of 127 days in the years 2010 and 2011. In 2012, the number of days with temperatures above freezing increased to 134.The number of summer days on which the sea ice in the southern Laptew Sea vanishes completely is also on the increase. “During the past two decades, there were, on average, fewer than 80 ice-free days in this region per year. During the past three years, however, we counted 96 ice-free days on average. Thus, the waves can nibble at the permafrost coasts for approximately two more weeks each year,“ says AWI permafrost researcher Paul Overduin.
Not only a problem in Siberia
Sea ice plays an important role in protecting coasts from waves. When this barrier is not there, the waves dig deep and erode land away. I saw the results of this first-hand during a trip to Barrow, Alaska, in 2008. I visited sites at Point Barrow, the northernmost point of the United States, where villages had been washed into the sea. On a trip to Greenland in 2009, I was amazed to see buildings being artificially cooled to avoid them sinking into the ground as warming temperatures melt the permafrost.
In the area of Siberia investigated by the German scientists, high cliffs protect the coastline. As the permafrost melts above and waves cut in from below, the cliffs are undermined and break off.
The erosion does not only have an impact on land. It also washes material into the sea, changing the quality of the water. Depending on the kind of erosion and the particular structure of the coast, between 88 and 800 tons of plant-, animal, and microorganism-based carbon are currently washed into the sea per year and kilometer of coastline – materials which were previously sealed in the permafrost, according to the AWI researchers. Once in the water, carbon may turn into carbon dioxide and, as a result, contribute to the acidification of the oceans.
The studies were conducted as part of the PROGRESS project which is funded by the German Federal Ministry of Education and Research. PROGRESS is the acronym for Potsdamer Forschungs- und Technologieverbund für Naturgefahren, Klimawandel und Nachhaltigkeit (Potsdam Research Cluster for Georisk Analysis, Environmental Change and Sustainability).
DateOctober 31, 2013 | 1:46 pm
“Poles apart” on the Arctic?
Intrigued by a tweet from the British Guardian, “Arctic melt means more pirate chases, say Polish climate hosts”, I clicked on to the website of the organisers of this year’s UN climate talks, to be held in the Polish capital Warsaw next month. Alas, the blog where the offending entry had been posted has been temporarily closed, leaving only this message:
“For the time being we decided to take some time away from our blog. Our idea was to focus attention on important issues that need good solutions and spark discussions on those. We did not foresee that some readers would take the presented texts literally as the official Polish position. Notwithstanding we would like to express regret as some of you found the text to be inappropriate. We acknowledge these criticisms. It was certainly not our aim to offend anybody. We will take due care that all new articles and posts on this website are written in a clear and sensitive manner so as to avoid misunderstandings. Stay tuned for more ideas.”
Unbelievable. The people responsible for the COP19 website have not felt obliged to write carefully up to now? People have been able to put their own “non-official” views on there? Well, the aim of “sparking discussions” has certainly been achieved, if not in the way the conference organisers intended. I will have to refer you to the Guardian if your curiosity is aroused as to what was actually on the blog before it was closed. Let it suffice here to quote the possibility mentioned there of “chasing the pirates, terrorists and ecologists that will come to hang around…” in the developing Arctic. No wonder Greenpeace and WWF amongst others called for the post to be removed. “Pirates, terrorists and ecologists”?
Poland’s hosting of the conference is in itself controversial, given that the country receives almost all its electricity from coal. The conference partners listed on the website include PGE, the Polish Energy Group which runs several coal power plants in the country, including the largest coal-fuelled thermal power plant in Europe, Belchatow.
Poland, you will have to smarten up your act and drastically improve your communications in the run-up to a key conference that should pave the way for emissions reductions in the interest of the Arctic and the rest of the planet. Assuming you are taking this issue seriously?
DateOctober 11, 2013 | 9:55 am
Greenpeace Arctic Protest in Germany
Greenpeace campaigners were on the streets around the world on Saturday October 5th, protesting against the arrest of the Arctic Sunrise crew by the Russian coastguard. For a short summary of the background, see “Greenpeace holds rallies...” on our DW environment page.
I paid a visit to the stand set up in our local shopping centre, Bad Godesberg, to see what was happening. Greenpeace Bonn were working hard to persuade shoppers on a drizzly October morning to sign the online protest against the arrests. It was interesting to see a mix of younger and more experienced campaigners outside the town theatre. There was also quite a wide age range amongst the passers-by who stopped to find out what was happening or even sign the online petition to have the Arctic Sunrise crew freed.
The controversy has certainly brought a lot of attention to the Arctic. I have the feeling there is a growing awareness here of the whole issue surrounding climate change, melting Arctic ice, and the difficulties involved in the economic development of such an ecologically sensitive area. Still, most people do not realise how relevant the “distant” Arctic is to all of us, given the role it plays in influencing climate change as a whole, our weather patterns and, of course, with the huge Greenland ice sheet, global sea levels.
DateOctober 7, 2013 | 11:29 am
Ice Blog back online!
Apologies for the absence of icy news on the blog over the past three months. I was collecting new stories and pictures of glacier development in the Swiss Alps during a hiking holiday and unfortunately slipped on some ice. It has taken me three months to recover, but before that I did take plenty of pictures, some of which will be appearing on the blog at some point in the next few weeks. I first visited that particular area in 1984, so have photos as well as memories of the glaciers as they looked then, and now. A comparison shows major changes. Many areas which were then iced over are now completely ice free.
In the meantime, of course, there has been no shortage of news and stories in the world at large relating to the polar regions and climate, including the annual sea-ice minimum measurements and the IPCC report.
As for the sea-ice measurements, the scientists from Germany’s Alfred Wegener Institute say the fact that the sea ice covered a bigger area than last year does not mean the ice pack is recovering. Its extent is still very low compared to the long-term average, and is in line with an overall trend towards less of the stable, thicker multi-year ice. A new study published this week suggests the Arctic will be ice-free in summer within 25 years. See this summary and context from the Climate News Network: Ocean damage is worse than thought.
The IPCC report includes a lot more data on developments at the poles, which was lacking in the last report. Ice melt from the Greenland and Antarctic ice sheets are shown to be playing a much greater role in increasing sea levels than previously thought. There’s a brief summarizing article on the DW environment page.
More on the “state of the ice” in the coming week. Please look out for regular posts from your Ice Blogger again from now on. It’s great to be back in action.
DateOctober 4, 2013 | 11:04 am
The “big Greenland melt”
- Melting Ice off Greenland.
Just recently I interviewed a scientist who told me he assumed last year’s record melt in Greenland was a one-off thing and not necessarily a result of climate change. Or rather, he said, it was impossible to say until we see whether it actually happens again. Given that the Greenland ice sheet is the biggest ice mass in the northern hemisphere and would also have a huge impact on global sea levels if it melts, it is encouraging to know that a huge effort is going on to find out exactly what is happening.
Ice Blogger’s gallery on climate change in Greenland
Audio feature on climate change in Greenland (Irene Quaile, for DW)
Tim Radford of Climate News Network has just published an article on the subject, with an excellent overview. He quotes scientists from Sheffield, UK, who have come up with a new theory. This is what Tim has to say. I quote at length, as it such a good summary of what has been happening and the possible explanations so far. Thanks Tim Radford and Climate News Network for drawing our attention to the latest research and filling in so much background. Over to you:
“First: the story so far. For a few days in July 2012, almost 97% of the surface of Greenland began suddenly to thaw. This was a melt on an unprecedented scale.
Greenland carries a burden of three million cubic kilometres of ice and even in the summer, most of it stays frozen, partly because of the island’s high latitude and partly because ice reflects sunlight, and tends normally to serve as its own insulator.
The event was so unusual, and so unexpected, and on such a scale that nobody seriously suggested that the dramatic conversion of snow to slush was direct evidence of climate change because of human-induced global warming.
Soot, smoke and heat
At first, climatologists were inclined to see the thaw as a consequence of the record-breaking heat waves and forest fires that afflicted North America last summer: snow could have been darkened by columns of soot and smoke from forest fires, just enough to start absorbing the sunlight, some reasoned.
Then in April a team at the University of Wisconsin-Madison suggested that freak cloud behaviour over Greenland at the time might have caused the melting. Clouds normally block sunlight and keep the terrain below them cool.
But these clouds could have been thin enough to let solar radiation through, but thick enough to trap the consequential infra-red radiation from the ground, and raise the local temperature levels.
Now Edward Hanna and colleagues at Sheffield report in the International Journal of Climatology that they have another explanation. Unusual atmospheric circulation and changes in the jet stream – the same changes that almost washed away summer in England – sent a blister of warm air sweeping over the ice sheet.
Hanna and his team analysed all the weather data collected by the Danish Meteorological Institute and by US researchers, and then employed satellite readings and a computer simulation called SnowModel to reconstruct the strange turn of events. And climate change may after all be a suspect.
High melt years
The Greenland Ice Sheet is a highly sensitive indicator of regional and global change, and, says Prof Hanna, been undergoing rapid warming, and losing ice, for at least the last five years and probably the last 20.
“Our research found that a ‘heat dome’ of warm southerly winds over the ice sheet led to widespread surface melting.” This was not predicted by the climate models used by the Intergovernmental Panel on Climate Change, and perhaps that indicated a deficiency in those models, he suggested.
The event seemed to be linked to changes in a phenomenon known to oceanographers and meteorologists as the summer North Atlantic Oscillation (NAO), another well-observed high pressure system called the Greenland Blocking Index, and the polar jet stream, all of which sent warm southerly winds sweeping over Greenland’s western coast.
“The next five to 10 years will reveal whether or not 2012 was a rare event resulting from natural variability of the NAO or part of an emerging pattern of new extreme high melt years.” It was hard to predict future changes in the Greenland climate in the current state of knowledge, but important to keep on trying.
There is an awful lot of ice on top of Greenland. Once it starts to melt, it is likely to be, say the Sheffield scientists, “dominant contributor to global sea level change over the next 100 to 1,000 years.”
Tim Radford, Climate News Network, 18.6.2013.
The Ice Blogger is heading off for a short break. Back July 8th, with new ice and snow pictures, I hope!
DateJune 26, 2013 | 10:59 am