Search Results for Tag: Antarctic
Ice paradoxes from pole to pole
Returning after a longish break with little access to news and data, there are several ice and snow stories jumping out of my mailbox at me. I’ve picked out two which those of a skeptical persuasion might say disprove some key climate assumptions, but which actually, in fact, confirm some trends and predictions.
Worrying, but not unexpected, are the latest measurements of the extent of the Arctic sea ice. In February, the experts at the National Snow and Ice Data Center (NSIDC) based in Boulder, Colorado, noted a record for the lowest observed maximum sea ice extent. Although it seems the sea ice did grow at some points during March, the overall for the month was the lowest recorded since satellite measurements began in 1979. The average extent for the month was 14.39 million square km – some 1.13 million square km below the 1981-2010 long-term average. The previous March low of 14.45 million square km was recorded in 2006.
In the Arctic Journal, Kevin McGwin quotes Andy Mahoney, a geophycisist with the Sea Ice Group at the University of Alaska Fairbanks, as saying the irregular pattern, with a kind of “double dip”, with the ice decreasing, increasing, then decreasing again, is “a pretty unusual event, regardless of the reason”. Normally, the ice levels would increase to the seasonal maximum first in March, then decline.
One reason, Mahoney says, could be the wind blowing ice into the regions where ice growth was observed, according to the NDSIC the Bering Sea, Davis Strait and around Labrador.
No contradiction to climate warming theory
The NSDIC says warm conditions in the Bering Sea and the Russian Sea of Okhotsk contributed to the record low winter ice maximum.
The overall downward trajectory, however, is clear. The brief increase in March is not a sign that the sea ice is recovering. Mahoney told the Arctic Journal parts of Alaska had seen abnormally high temperatures this winter, which was in line with the overall seasonal ice observations.
“What drives the maximum extent is what happens at the margins, and they can grow and retreat due to short-term variants. The conditions in the central Arctic, far from the action, are indicative of the warm year we’ve had in Alaska,” he said. Barrow, on Alaska’s northern coast, far away from the southern margin, for example, saw a lot of broken ice this winter, according to Maloney.
WWF expressed concerned about the latest figures:
“This is not a record to be proud of. Low sea ice can create a series of reactions that further threaten the Arctic and the rest of the globe,” said Alexander Shestakov, Director, WWF Global Arctic Programme.
“This chilling news from the Arctic should be a wakeup call for all of us,” said Samantha Smith, the leader of WWF’s Global Climate and Energy Initiative. She stresses the need to cut global emissions to halt the Arctic melt.
The proportion of thick Arctic ice that lasts multiple years has dwindled over the past two decades. A recent study shows that Arctic sea ice has thinned by 65 per cent since 1975, leaving ice that is more susceptible to melting.
Writing for Alaska Dispatch News (AND), Yereth Rosen notes that the most dramatic changes in the Arctic sea ice extent have been in the melt season, not in the period of maximum winter coverage. He quotes NSIDC scientist Julienne Strove, who led a study published last year in Geophysical Research Letters which showed the open-water season is lengthening, mostly because of extended melt in summer and autumn. So is this additional winter record a sign of more melting to come? Only time will tell, but the signs are not looking good.
A story from the opposite pole has also attracted attention. It says climate change is actually increasing the amount of snow in the Antarctic. Puzzling? Not necessarily.
More heat, more snow?
An international study headed by Germany’s Potsdam Institute for Climate Impact research (PIK) comes to the conclusion that every degree of regional warming could increase snowfall there by around five percent. The estimate is based on ice cores and climate modeling.
The information adds a new element to calculations of how much the Antarctic will contribute to global sea level rise. Some people might assume more snow would stop the Antarctic from losing mass. In fact the increasing weight of new snow and ice can make it slide towards the coast and into the ocean faster. In this connection, you might like to read some more stories on these Antarctic issues:
Anders Levermann, one of the new study authors, whom I have spoken to several times on the effects of climate change on the Antarctic and global sea levels, says the latest results back up earlier conclusions that the Antarctic will lose more ice than it will gain and thus have a major influence on global sea level. Levermann, from PIK, is also one of the lead authors of the sea-level chapter of the IPCC report. He stresses that the latest study just provides yet another piece of the “jigsaw puzzle” coming together on how global sea level is likely to develop in the future.
If the world leaders called on to come up with a new world climate agreement at the end of this year need any more motivation, this scientific research from both ends of the world should really give them an extra push.
DateApril 10, 2015 | 3:01 pm
Thick Antarctic ice not sign of cooling
The recent publication of a study on Arctic ice as measured by the “yellow submarine”, an underwater robot, caused a flurry of comments on the “climate hoax” by some of those of a “climate-sceptical” persuasion. I contacted a sea ice physicist at Germany’s AWI Institute for an independent opinion. Here’s the background:
Measurements conducted by an underwater robot have found that Antarctic sea ice is much thicker than previously thought in some places. Much of this floating sea ice is underwater, hidden from the satellites which have been tracking seasonal sea ice for decades. The satellite data is normally validated by drilling into ice floes which can be reached by ship, or visual estimates from the ships themselves. However, it is difficult to reach the thickest ice that way.
Underwater robot below the ice
Over the last four years, an international group of researchers has been mapping the bottom of sea ice in several areas of the Antarctic using an underwater robot, or AUV. It can swim to a depth of some 30 metres (100 feet) and uses sonar directed upwards to survey the bottom of the sea ice. This gave them access to areas where measurements could not be carried out until now.
The study, published in the journal Nature Geoscience, suggests that the average ice thickness could be considerably higher than previous estimates. In three regions surveyed, the robot sub found that deformed, thickened ice accounted for at least half of and as much as 76 percent of the total ice volume, the researchers say.
Climate skepticism vindicated?
While Antarctica’s ice sheet, that is the land ice, is melting and retreating, the extent of the sea ice has been expanding over the last three winters. This has led some who are skeptical about climate change to suggest that it could be evidence that human-made global warming is not happening. But sea-ice physicist Stefan Hendricks, from the Alfred-Wegener Institute for Polar and Marine Research, based in Bremerhaven, Germany, told me in an interview the new measurements were no reason to doubt climate change is happening.
“What our colleagues have shown is that ship-based measurements do not record this really thick ice. That is no surprise to us. It is good that they have found this out, but basically it just tells us that we have to be cautious when it comes to using ship-based data”, Hendricks said.
The sea ice extent in the Antarctic has been growing, while the sea ice in the Arctic, at the northern end of the planet, has decreased dramatically in recent years. Hendricks stresses that the two regions are completely different:
“The Arctic Ocean is surrounded by land, whereas in the Antarctic, the land is in the middle. If the Arctic were not surrounded by land, the ice cover would also be much bigger in winter”, says Hendricks. The increase in Antarctic sea ice in winter can be partly explained by the wind direction, he adds . Ice grows faster, the thinner it is. If it is blown out from shore, for instance into the Indian Ocean, new ice is created very quickly, according to the ice expert. He also warns against comparing what happens to the Arctic in summer to what happens at the southern end of the planet in winter:
“If you look at the cycle over the whole year, your will see that the sea ice in the Antarctic also melts almost completely in summer”.
Valuable data, limited application
Still, the German expert says the new ice measurements from the Antarctic are of major importance to our understanding of how sea ice behaves. But he stresses that the ice floes are on the move all the time. Although the measurements are very exact, the situation is constantly changing ,and the measurements could only be taken at a limited number of spots in what is a huge area of ice.
“The question is how representative is this for the total ice extent? This depends to a very large extent on which ice floe you take. There are large differences between them. The differences are particularly marked if you go further away from land. Close to land, the ice piles up and is deformed and so you get this very thick ice. Further out, you don’t get that”.
The new measurements certainly do not give any reason to be more relaxed about climate warming, says Hendricks. Increased sea ice could have a cooling effect, as ice reflects heat back into space, whereas the sea water absorbs the heat, exacerbating warming. But given that the ice melts again in summer, that effect would be very slight, says the physicist.
DateDecember 4, 2014 | 3:31 pm
Climate action from Peru to Paris
Today is the first of December. It’s the start of the meteorological winter in the northern hemisphere, towards the end of what looks set to be the warmest year since records began. It is also the day when the annual UN climate conference gets underway in Lima, Peru. Negotiators from around the world will try to hammer out the details of a new World Climate Agreement to halt global warming by reducing CO2 emissions. For our polar ice, that agreement can’t come fast enough.
After five years of frustration following the failure of the Copenhagen climate summit in 2009, 2014 may well go down in history as the year when climate change made a comeback onto the international agenda. Although there is still one year to go until the key Paris meeting which is scheduled to come up with a new World Climate Agreement to replace the Kyoto Protocol, 2014 has seen several milestones on the path to a low-carbon future.
In September, the UN Secretary General Ban Ki Moon gave the issue top priority, by holding his own special climate summit in New York. It was accompanied by marches in the USA and other parts of the world, organized by a growing grassroots movement to combat climate change. Meanwhile, the world’s biggest emitters, China and the USA, finally signaled their intention to commit to action on climate change.
No time for delay
The latest report by the Intergovernmental Panel on Climate Change, the IPCC, has left no doubt about the need for urgent action, says Professor Stefan Rahmstorf from Germany’s Potsdam Institute for Climate Impact Research:
“We see that global temperatures have risen by almost one degree centigrade in the last 100 years, we see that global sea level has risen by nearly 20 centimeters in the last 100 years. We see that the mountain glaciers and the Arctic ice cover is in retreat, the continental ice sheets in Greenland and Antarctica are shrinking, losing mass, contributing to sea level rise, we see extreme events on the rise. For example the number of record-breaking hot months has increased five fold as compared to what you get by chance in a stationary climate.”
The international community has agreed, based on the scientific evidence available, that a temperature rise of two degrees is the maximum possible without exposing the world to potentially devastating climate change. That means limiting the greenhouse gas emissions that are warming the planet. But with those emissions still on the rise, that goal is nowhere in sight, says Rahmstorf, and climate change is already having an impact after just under one degree of warming:
“If we don’t stop this process, we will go well beyond two degrees centigrade, and we will leave the range we are familiar with throughout human history. We will be way outside that into uncharted and I think very dangerous waters.”
Peru prepares the way for Paris
Experts see the world on track for a temperature rise of at least four degrees, unless emissions are reduced substantially in the very near future. The latest figures indicate that to stay within the two degree limit, emissions would have to peak within the next ten years and the world become virtually carbon-neutral in the second half of this century.
That is why Peru, like every climate conference, is important, says UN climate chief Christiana Figueres. She stresses that climate protection is an ongoing process. Countries have until March 2015 to put their planned contributions on the table. The EU made a start by announcing its targets last month. The USA and China went on to give encouraging signals:
“The fact is that most countries around the world are currently doing their homework and figuring out on a national scale what is financially, politically, economically, technically possible for them to contribute towards the solution,” says Figueres.
But while that homework continues in the countries of the world, the negotiators assembling in Lima will have to make progress on drafting the universal climate agreement, which is scheduled to be agreed in Paris in December 2015 and to come into effect in 2020.
A price on CO2
Ottmar Edenhofer is the chief economist at the Potsdam Climate Institute. He is also co-chair of the IPCC group concerned with ways of tackling climate change. He says the world has only around 20 to 30 years left to solve the emissions problem. He stresses it is not a question of technology. Alternative energy technologies are there to solve the problem. Yet fossil fuels have been enjoying a renaissance, says the climate expert. The key, he says, is to put a price on carbon, making it too expensive to pump CO2 into the atmosphere. The world only have a limited carbon budget. That means we can only put another one thousand gigatonnes of CO2 into the atmosphere to keep temperature rise below the two-degree threshold and avoid the risk of what Edenhofer describes as “very severe climate change impacts”.
“Space to store CO2 in the atmosphere is becoming scarce”, Edenhofer explained to me recently during a visit to Potsdam. “And when things are scarce, you have to put a price on them. That is the only way to show investors, consumers and companies where they should be investing their money.” The window of opportunity is closing, says Edenhofer. If we keep on with business as usual, we will have used up all our carbon budget in two to three decades.
UN climate chief Figueres agrees that putting a price on pollution by CO2 is a very important component of the shift towards a low carbon economy.
“What we have done over the past 150 years is assumed there is no cost to the irresponsible use of the environment, and we have proceeded as though the environment were constantly renewable, where it is not”, Figueres told me in an interview conducted in her office here in Bonn, right next to our Deutsche Welle building. Putting a price tag on CO2 emissions would mean they could be costed in economic decision-making.
Haggling out the details
The negotiators in Lima have their work cut out for them. Countries with large fossil fuel reserves are reluctant to agree to emissions reductions which would destroy their source of revenue. But Edenhofer is optimistic that ultimately all countries will realize that climate change will pay off in the end.
„We have to assume that people will see sense. They will realize that the long-term consequences of business as usual will be irreversible climate change, with all the problems that brings with it”.
The economist says protecting the climate would also bring the kind of short-term benefits politicians are looking for. He cites the change in China’s policies as an example:
“The drastic air pollution in Beijing is already making it less attractive as a business location. And the reason the Chinese government is thinking very seriously about reducing emissions is because it would also be a step towards improving their air quality.”
Funding boost for UN talks
After years of stagnation and frustration, there are signs that progress is being made on climate change. At a key meeting in Berlin this month, countries pledged a total of almost 10 billion dollars to the Green Climate Fund, which was set up to help poorer countries adapt to climate change. This could motivate developing countries and emerging economies to sign up to a new world climate agreement. So far, many of them have been reluctant to limit their own emissions, as the wealthy industrialized states are the ones who have caused the problem by emissions in the past.
Although both the money pledged for adaptation and the emissions cuts proposals currently on the table are still insufficient and things are moving slowly, German scientist Rahmstorf compares the likelihood of a breakthrough to the fall of the Berlin Wall, 25 years ago.
“If you had asked people just a few months before that how likely it was that the wall comes down, nobody would have said it’s going to happen”, says the Potsdam expert and IPCC author. He says these kind of processes in society are hard to predict – and the signs are encouraging.
He cites the “huge success story” of renewable energies and the considerable emissions reductions by the EU countries since 1990 as encouraging signs. This did not hamper economic growth, says Rahmstorf:
“It shows that your can decouple emissions from economic growth and welfare”.
Ultimately, halting climate change is not something which can be achieved solely within the UN negotiations. This year for the first time a pre-conference meeting was held in Peru to involve non-governmental groups in the process. The transition to a climate-saving low-carbon society requires action across the board. But it is the governments of the world who have to enter into binding agreements, and that means plenty of hard work ahead for the negotiators in Peru over the next two weeks.
Listen to my Peru conference preview on Living Planet.
DateDecember 1, 2014 | 2:21 pm
Acid Arctic Ocean and Russell Brand?
Is ocean acidification a term you are familiar with? If you are a regular Ice Blog reader, I would like to think you will be. But I am prompted to ask this question because the term came up during a discussion at a weekly evening class I attend, and I was flabbergasted that none of the people there had a clue what it meant. These were all university-educated professionals. That means we in the media have our work cut out for us explaining how climate change is making the seas more acidic, and why this is something we should be worried about.
This incident has reminded me that we journalists have to avoid assuming that everyone is familiar with the terms we use in our coverage on a regular basis. Climate change is the kind of topic where you want to reach a specialist audience, but also the vast majority of the population. We all have to change our habits to reduce CO2 emissions, and we all have to vote for the politicians who have the responsibility for energy and environment policy. That means we need to talk about the problems in a way everybody understands.
I am encouraged to see the BBC website had a longer article on the threat of ocean acidification a few days ago. I don’t think it has made its way into the tabloids though, correct me if I am wrong.
I was made very aware of the issue during a trip to Arctic Spitzbergen in 2010 with a team of scientists monitoring just what happens to the life forms in the sea when it becomes more acidic because it is absorbing so much of the CO2 we emit. The polar regions are suffering more than others, as cold water absorbs CO2 faster.
Towards the end of last year, I interviewed Professor Alex Rogers from the University of Oxford, who is also the scientific director of the International Programme on the State of the Oceans, which had just published a major study on acidification.
Listen to the interview:
He told me: “The oceans are taking up about a third of the carbon dioxide we’re producing at the moment. While this is slowing the rate of earth temperature rise, it is also changing the chemistry of the ocean in a very profound way.”
Carbon dioxide reacts with sea water to form carbonic acid. Gradually, this makes oceans more acidic.
Threat to marine life
Sea water is already 26 percent more acidic than it was before the onset of the Industrial Revolution. According to the IPSO report, it could be 170 percent more acidic by 2100.
Over the last 20 years, scientists around the world have been conducting laboratory experiments to find out what that would mean for the flora and fauna of the oceans. Ulf Riebesell of the Helmholtz Institute for Ocean Research in Kiel, a lead author of the report, conducted the world’s first experiments in nature, off the coast of the Arctic island of Svalbard in 2010. This was the project I visited.
Giant test-tubes were lowered into the ocean to capture a water column with living organisms inside it. Different amounts of CO2 were added to simulate the effects of different emissions scenarios in the coming decades. The experiments showed that increasing acidification decreases the amount of calcium carbonate in the sea water, making life very difficult for sea creatures that use it to form their skeletons or shells. This will affect coral, mussels, snails, sea urchins, starfish as well as fish and other organisms. Scientists say some of these species will simply not be able to compete with others in the ocean of the future.
Hard times for coastal residents
All this will have severe economic and social consequences. Ultimately, acidification will affect the food chain. Tropical and sub-tropical areas with warm-water corals are going to suffer. Coral reefs are home to numerous species, serve as nurseries for fish and are a valuable tourist attraction. They also protect coastlines against waves and storms.
At the same time, the polar regions are suffering more than others, as cold water absorbs CO2 faster. Riebesell told me the experiments in the Arctic indicate that the sea water there could become corrosive within a few decades. “That means the shells and skeletons of some sea creatures would simply dissolve.” What a horrific prospect.
The Antarctic is already affected. IPSO’s Alex Rogers told me: “We’re seeing instances where we’re finding tiny shelled molluscs, tiny snails that swim in the surface of the oceans, with corroded shells.”
These creatures play a key role in the marine food chain, supporting everything from tiny fish to whales. “One of our primary sources of marine-derived protein is in rapid decline,” says Monty Halls, manager of the UK-based Shark and Coral Conservation Trust. He describes ocean acidification as the “most serious threat to our children’s welfare.” Monty is working to produce video and cartoon material to interest the younger generation in the need to change our behavior to protect marine life.
Two German scientists Antje Funcke and Konstantin Mewes have written and illustrated a children’s story called Tipo and Tessi to make kids aware of the need to protect the ocean. So far, it has only been published in German. The English translation is available, but so far there is a lack of funding for publication.
Vicious circle of climate change
Scientists are also concerned about a feedback effect that will further exacerbate global warming. In the long run, the ocean will become the biggest sink for human-produced CO2, but it will absorb it at a slower rate. That means the more acidic the ocean becomes, the less capacity is has to act as a buffer.
Alex Rogers sees a further problem: “Carbonate structures actually weigh down particular organic carbon. In other words, they help carbon to sink out of the surface layers of the ocean into the deep sea. Anything that interferes in that process can potentially accelerate the rate of CO2 increase in the atmosphere.”
And that would be very dangerous. “The rates of CO2 increase we are seeing at the moment are probably as high as they’ve been for the last 300 million years,” says Rogers.
The IPSO scientists draw an unsettling comparison between conditions today and climate change events in the past that have resulted in mass extinctions. They say a lot of these major extinction events occurred in connection with high temperatures and acidification, similar effects to the ones that we are experiencing today.
The BBC article I mentioned earlier also mentions new research by scientists at Exeter University, indicating that increasing acidity creates conditions for animals to take up more coastal pollution, like copper. That would mean not only creatures with calcium-based shells would be endangered.
Find a celebrity champion?
The experts stress that it is not too late to halt the acidification process, although the CO2 will remain in the oceans for thousands of years. This brings me back to the topics of recent Ice Blog posts: the UN climate negotiations and the need for urgent action. And of course, to the mention in the title above of the British comedian Russell Brand. This relates to another issue I have been writing about recently: the question of celebrity involvement and whether that can help inform people about and interest them in topics like climate change and the acidification of our oceans. My commentary on this, with regard to Leonardo di Caprio at Ban Ki-moon’s September summit in New York, sparked some interesting discussions.
Just this morning I was reading about Russell Brand and how his new book calling for a revolution on all kinds of issues is attracting huge interest. I have noticed that people otherwise completely uninterested in politics and social issues are at least paying some attention because their favourite comedian is talking about them. Maybe we have to get Russell Brand on board. I’m not sure what kind of action he would advocate, but there would certainly be a lot fewer people who could say they’d never heard of ocean acidification.
DateOctober 31, 2014 | 12:27 pm
Polar melt confirmed from space
I am disappointed that there was so little mainstream media coverage (please correct me if I am wrong) of a report from a team of scientists from Germany’s Alfred Wegener Institute (AWI) in Bremerhaven who have analysed just over two years of data from the CryoSat-2 satellite. Their conclusion that the Greenland ice sheet and Antarctica’s glaciers are melting at record pace, dumping some 500 cubic kilometers of ice into the oceans every year, twice as much in the case of Greenland and three times as much in the case of Antarctica, by comparison with 2009 – yes, you read right, we are talking about a very short period for such a dramatic increase in ice loss – should have made more news headlines and not just the science pages.
To understand the scale of that, the researchers say it would be the equivalent of an ice sheet that’s 600 meters thick and covers an area as big as the German city of Hamburg – or, my colleagues here at DW calculate, as big as Singapore.
The research team headed by Veit Helm used around two years’ worth of data from the ESA CryoSat-2 satellite to create digital elevation models of Greenland and Antarctica. The results were published in the online magazine of the European Geoscience Union (EGU) The Cryosphere.
“The new elevation maps are snapshots of the current state of the ice sheets,” Helm says. “The elevations are very accurate, to just a few meters in height, and cover close to 16 million square kilometers of the area of the ice sheets.” He says this includes an additional 500,000 square kilometers that weren’t covered in previous elevation models from altimetry.
Space technology shows declining ice mass
Helm and his team analyzed all data from the CryoSat-2 radar altimeter SIRAL in order to come up with the detailed maps. The satellite with this new radar equipment was launched in 2010. Satellite altimeters measure the height of an ice sheet by sending radar or laser pulses which are then reflected by the surface of the glaciers or surrounding areas of water and recorded by the satellite.
The researchers used other satellite data as well to document how elevation has changed between 2011 and 2014.
Rapid ice loss over a short period of time
The team used more than 200 million SIRAL data points for Antarctica and some 14 million data points for Greenland to create the elevation maps. The results show that Greenland alone is losing around 375 cubic kilometers of ice per year.
Compared to data which was collected in 2009, the loss of mass from the Greenland ice sheet has doubled. The rate of ice discharge from the West Antarctic ice sheet tripled during the same period.
I think this is definitely worth talking about. We know the huge implications of polar ice melt for global sea levels. Other research from this year also tells us that, at least in the case of parts of Antarctica, the ice melt is probably irreversible.
We cannot afford to ignore what is happening to the ice sheets. The extent of ice loss in Greenland is particularly dramatic. I am losing patience with those people who respond to studies like this and our reporting on it by saying “but the East Antarctic is gaining volume” and “the Antarctic sea ice has grown”. It is so easy to take things out of context and mix different factors up when trying to understand a very complex system.
I will give the last word here to AWI glaciologist Angelika Humbert, who co-authored the study: “If you combine the two ice sheets (Greenland and Antarctic), they are thinning at a rate of 500 cubic kilometers per year. That is the highest rate observed since altimetry satellite records began about 20 years ago.” It seems to me there is no arguing with that.
DateAugust 22, 2014 | 1:33 pm