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Extreme Arctic Melt Could Increase Sea Level Rise Twice as Fast as Previously Estimated

Extreme Arctic melt could increase global sea level rise twice as fast as previously estimated and cost the world economy between $7 trillion and $90 trillion by 2100, a new analysis shows.

The assessment from the Arctic Monitoring and Assessment Program projects that increased ice melt in the Arctic could contribute to an overall 20 to 29 inches of global sea level rise over the next century—nearly double the minimum estimates provided by the UN Intergovernmental Panel on Climate Change.

The Arctic warmed faster than any other region on earth between 2011-2015 and the assessment speculates that the Arctic Ocean could be ice-free in the summer by 2040.

"The Arctic is continuing to melt, and it's going faster than expected in 2011," Lars-Otto Reiersen, head of the Arctic Monitoring and Assessment Program (AMAP) which prepared the report, told Reuters.

"Multi-year ice used to be a big consolidated pack. It's almost like a big thick ice cube versus a bunch of crushed ice. When you warm the water, the crushed ice melts a lot quicker."

For a deeper dive:

InsideClimate News, Reuters, Miami Herald

For more climate change and clean energy news, you can follow Climate Nexus on Twitter and Facebook, and sign up for daily Hot News.

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A 130-metre-wide waterfall drains meltwater from the Nansen Ice Shelf into the ocean. Stuart Rankin via Flickr

Giant Waterfall in Antarctica Worries Scientists

By Tim Radford

Scientists poring over military and satellite imagery have mapped the unimaginable: a network of rivers, streams, ponds, lakes and even a waterfall, flowing over the ice shelf of a continent with an annual mean temperature of more than -50C.

In 1909 Ernest Shackleton and his fellow explorers on their way to the magnetic South Pole found that they had to cross and recross flowing streams and lakes on the Nansen Ice Shelf.

Antarctic Waterways

Now, U.S. scientists report in the journal Nature that they studied photographs taken by military aircraft from 1947 and satellite images from 1973 to identify almost 700 seasonal networks of ponds, channels and braided streams flowing from all sides of the continent, as close as 600km to the South Pole and at altitudes of 1,300 meters.

And they found that such systems carried water for 120km. A second research team reporting a companion study in the same issue of Nature identified one meltwater system with an ocean outflow that ended in a 130-meter wide waterfall, big enough to drain the entire surface melt in a matter of days.

In a world rapidly warming as humans burn ever more fossil fuels, to add ever more greenhouse gases into the atmosphere, researchers expect to observe an increase in the volume of meltwater on the south polar surface. Researchers have predicted the melt rates could double by 2050. What isn't clear is whether this will make the shelf ice around the continent—and shelf ice slows the flow of glaciers from the polar hinterland—any less stable.

"This is not in the future—this is widespread now, and has been for decades," said Jonathan Kingslake, a glaciologist at Columbia University's Lamont-Doherty Earth Observatory, who led the research.

"I think most polar scientists have considered water moving across the surface of Antarctica to be extremely rare. But we found a lot of it, over very large areas."

The big question is: has the level of surface melting increased in the last seven decades? The researchers don't yet have enough information to make a judgment.

"We have no reason to think they have," Dr Kingslake said. "But without further work, we can't tell. Now, looking forward, it will be really important to work out how these systems will change in response to warming, and how this will affect the ice sheets."

Many of the flow systems seem to start in the Antarctic mountains, near outcrops of exposed rock, or in places where fierce winds have scoured snow off the ice beneath. Rocks are dark, the exposed ice is of a blue colour, and during the long days of the Antarctic summer both would absorb more solar energy than white snow or ice. This would be enough to start the melting process.

The Antarctic is already losing ice, as giant floating shelves suddenly fracture and drift north. There is a theory that meltwater could be part of the fissure mechanism, as it seeps deep into the shelves.

Drainage Theory

But the companion study, led by the polar scientist Robin Bell of the Lamont-Doherty Observatory suggests that drainage on the Nansen Ice Shelf might help to keep the ice intact, perhaps by draining away the meltwater in the dramatic waterfall the scientists had identified.

"It could develop this way in other places, or things could just devolve into giant slush puddles," she said. "Ice is dynamic, and complex, and we don't have the data yet."

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Massive Iceberg Hangs by 12-Mile 'Thread'

The growing rift in the Antarctic Peninsula has now lengthened to 110 miles, meaning that the Larsen C ice shelf is now connected to the main ice shelf by only a 12-mile "thread," USA TODAY reports.

The British Antarctic Survey determined that the crack has expanded by 50 miles since 2011.

"It is particularly hard to predict when it will occur," Adrian Luckman of Project MIDAS told USA TODAY about the eventual calving, which would create a Delaware-sized iceberg. "I am quite surprised as to how long it is holding on!"

"The rift (or crack) has continued to open, and the berg continues to drift outward at a very consistent rate," Luckman added.

However, he noted that the crack has not grown longer in recent weeks.

As EcoWatch mentioned previously, the loss of this portion of the ice shelf will not raise sea levels as it is already floating on the water. However, as these ice shelves disintegrate, the land-locked glaciers they hold back may begin sliding into the sea. If all of the ice the Larsen C ice shelf holds back slides into the ocean, it will raise sea levels globally by four inches.

According to Project MIDAS, "there is not enough information to know whether the expected calving event on Larsen C is an effect of climate change or not, although there is good scientific evidence that climate change has caused thinning of the ice shelf."

Temperatures at the Antarctic Peninsula, where the Larsen ice shelf is found, have risen by 2.5 degrees Celsius in the past 50 years.

Antarctica's ice shelves are indeed melting rapidly as ocean waters warm. Climate Nexus reported in October that three glaciers in West Antarctica have undergone "intense unbalanced melting," risking their stability and further acceleration of sea level rise.

Research published in Nature Communications found that the Smith, Pope and Kohler glaciers in the Amundsen Sea embayment collectively lost about 1,000 feet of ice from 2002 to 2009.

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A team from Rutgers University and the University of Georgia, led by Asa Rennermalm of Rutgers, measures meltwater runoff from the ice sheet margin in Greenland during summer 2013. Photo credit: Asa Rennermalm/Rutgers University

Greenland's Coastal Glaciers Rapidly Withering Away

Greenland's icy coastlines are withering away at a rapid pace. With ever rising temperatures in the region, scientists fear the glaciers may never grow back.

A team from Ohio State University discovered that about 20 years ago, melting on the island reached a tipping point. In this event, a layer of old snow called the firn, was frozen over and the ice sheet growth was stunted. This caused the new growth on the coastlines to halt. Combined with rising temperatures of the sea, the ice has been melting away in large sectors. At the rate it's going, the team said there will be a 1.5 inch increase in global sea level rise by 2100.

According to the study:

The find is important because it reveals exactly why the most vulnerable parts of Greenland ice are melting so quickly: the deep snow layer that normally captures coastal meltwater was filled to capacity in 1997. That layer of snow and meltwater has since frozen solid, so that all new meltwater flows over it and out to sea.

Though these findings are bad news, the researchers said there is no "immediate cause for panic." The Greenland Ice Sheet—the second largest ice cache in the world—is relatively intact. Associate professor at Ohio State, and co-author of the study Ian Howat, said the outer layers of ice contribute a small portion to the greater sheet, and that their melting may even be ephemeral, or seasonal to some degree.

"Since this 'tipping point' was reached in the late 90's before warming really took off, it indicates that these peripheral glaciers are very sensitive and, potentially, ephemeral relative to the timescales of response of the ice sheet," said Howat.

The areas in red are most at risk of being lost.

Though the entire coastline is not at risk, if it were to melt away, we'd see an uptake of a few inches in sea level. To put that in terms of the greater ice sheet, if the entire entity melted, we'd see a rise of 24 feet in total.

"These peripheral glaciers and ice caps can be thought of as colonies of ice that are in rapid decline, many of which will likely disappear in the near future," said Howat. "In that sense, you could say that they're 'doomed.' However, the ice sheet itself is still not 'doomed' in the same way. The vast interior ice sheet is more climatologically isolated than the surrounding glaciers and ice caps."

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Photo credit: Sea Shepherd Conservation Society

Fast and Furious Star Joins Sea Shepherd to Show Impact of Climate Change on Baby Seals

A Sea Shepherd team flew over the Gulf of St. Lawrence last week documenting an ecological disaster that very few people want to talk about—especially those in the Canadian government.

It has been 40 years to the month that French actress Brigitte Bardot first went to the ice floes in Canada to focus attention on the slaughter of baby seals at the behest of Sea Shepherd founder, Captain Paul Watson.

This year, actress Michelle Rodriguez—best known for her role as Letty Ortiz in the blockbuster franchise The Fast and the Furious—joined the all-woman survey team known as Operation Ice Watch. The group was led by Sea Shepherd Toronto coordinator Brigitte Breau and also included Yana Watson, the wife of Sea Shepherd leader Captain Paul Watson, Sea Shepherd advisory board member Clementine Pallanca and Canadian animal rights lawyer Camille Labchuk of Animal Justice.

The group was accompanied by a three-person documentary crew: French photojournalist Bernard Sidler, Australian videographer Jasmine Lord and Toronto-based Czech photographer Marketa Schusterova.

Since Captain Watson first founded Sea Shepherd 40 years ago in 1977, much has changed in the Gulf of St. Lawrence. Not all whitecoat seals are clubbed to death on the ice (shotguns are also permitted now), the kill quota is almost twice what it was then. Since 2011, the Canadian Department of Fisheries and Oceans has been allowing the slaughter of 400,000 seals they define as "adult" although many are no more than six weeks old.

Canadian seal products are banned in Europe and in the U.S. Regardless of the quota that has allowed sealers to kill 2.4 million seals over the last six years, only around 350,000 have actually been slaughtered in total because of a scarcity of markets.

However, there is one very significant change that the world needs to know.

Where is the Ice?

Harp seals cannot give birth to pups unless there is ice for them to be born upon. The team of Operation Ice Watch had trouble finding any substantial ice during its investigation.

Earlier in the week, the Operation Ice Watch crew found a couple of small patches along the coast of Cape Breton containing a few hundred seals and their pups. Two days later that patch was gone, broken up by high winds. It was found again two days later, more broken up and with fewer seals. Most likely the seal pups drowned.

There should be more than 200,000 seal pups in the Gulf yet no one seems to know where they are.

What the Operation Ice Watch team witnessed is something that Sea Shepherd has never witnessed before—a completely ice-free and seal-free Gulf. This alarming sight means that without ice, seal pups cannot be born. They are being birthed into the sea, only to drown or forced up on land where they have little chance of survival.

Despite the lack of ice, the Canadian government has issued a kill quota once again of 400,000 seals for the year 2017. This is an astounding figure when tens of thousands of seals may have already perished in the Gulf of St. Lawrence this year due for lack of ice.

Captain Watson and Sea Shepherd feel this should be declared a national emergency and a clear warning that climate change is accelerating faster than authorities anticipate.

Brigitte Bardot and Michelle Rodriguez: Posing With Seals Then and Now

Captain Paul Watson sent the all-female crew to the ice to commemorate the courage of Brigitte Bardot when she went to the ice in 1977 to focus international attention of the slaughter of seals. A photo of Bardot posting with a seal brought world attention to the cause and the need to protect harp seals. It became a pivotal point in the fight to stop this annual Canadian obscenity of cruelty and mass slaughter.

Bardot and Seal, 1977.

In recognition of Bardot's famous picture, taken 40 years ago this March, Rodriguez posed with a whitecoat baby seal in her own 21st Century version of the iconic photo.

Michelle Rodriguez posed with a whitecoat baby seal in her own 21st Century version of the iconic photo.Sea Shepherd Conservation Society

"People listen to celebrities," said Captain Watson. "Michelle has over 13 million friends on her Facebook page along with an international following. This helps to get the message out that now the seals are not just threatened by human hunting, but even more threatened by climate change and the loss of ice. Not content to kill the babies, mankind has now wiped out the nurseries."

However, unlike the ice conditions of 1977 which made Bardot's photoshoot a relatively safe one, it was not so easy to recreate the shot in 2017. The ice was so broken up and thin that Sea Shepherd's helicopter could not land. Rodriguez, along with Yana Watson, Sidler and Lord had to hop from one small pan of ice to another just to reach the seals.

Despite the challenges, Rodriguez was thrilled to meet the seals on the small patch of ice.

"Seeing these beautiful creatures and understanding their place in the ecosystem, I'm saddened the Canadian government has been so short sighted in failing to prevent a massive ecological catastrophe," said Rodriguez. "It's sad to know the truth and watch the world turn a blind eye."

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Photo credit: NASA / Kathryn Hansen

Sea Ice Falls to Record Lows in Both the Arctic and Antarctic

By Roz Pidcock

The Arctic and Antarctic have experienced record lows in sea ice extent so far in 2017, according to the latest data from the U.S. National Snow and Ice Data Center (NSIDC).

At about this time each year, the Antarctic reaches its lowest extent for the year while the Arctic reaches its highest. The new satellite data, released Wednesday, confirms that there is less sea ice globally than at any time in the entire 38-year satellite record.

The NSIDC doesn't usually release data for both poles simultaneously, but has done so this time because of what scientists have dubbed an "exceptional" year in 2017.

The news comes as the World Meteorological Organization confirmed this week that 2016 "made history" with record high global temperatures and low sea ice. Many of last year's extreme conditions have continued into 2017, the report noted.

Arctic Low

With just 14.42m square kilometers on March 7, this year's winter maximum in the Arctic ranks as the smallest in the satellite record, for the third year in a row.

This year's maximum extent is 1.22 million square kilometers below the 1981 to 2010 average maximum of 15.64 million square kilometers, NSIDC confirmed Wednesday.

Record low sea ice extent in February continued a string of records over the winter months, from October through February. A "heatwave" in mid-November caused some parts of the Arctic to be 15ºC warmer than usual, for example.

Carbon Brief

The Arctic winter maximum has been shrinking by about three percent per decade. The decline is much faster for the summer minimum in September, at more like 13 percent per decade. Recent research shows up to two-thirds of the drop is a direct result of human activity.

Ice lost from the Arctic can have consequences much further afield, as a new WMO report explained:

"Scientific research indicates that changes in the Arctic and melting sea ice is leading to a shift in wider oceanic and atmospheric circulation patterns. This is affecting weather in other parts of the world because of waves in the jet stream—the fast-moving band of air which helps regulate temperatures."

As we enter 2017's summer melt season, Arctic sea ice looks vulnerable. This is especially so, given that the latest sea ice thickness observations from the CryoSat-2 satellite show very thin ice in a number of regions, said Zack Labe, a PhD student studying sea ice at the University of California. That said, it's too soon to tell if we'll see a record low minimum come September, he told Carbon Brief:

"Weather has a big role in the summer melt season, so speculations are challenging as to whether 2017 will be a new record minimum."

Arctic sea ice extent for March 7 was 14.42 million square kilometers. The orange line shows the 1981 to 2010 median extent for that day.U.S. National Snow and Ice Data Center

Greenland

While the behavior of Arctic sea ice tends to attract the biggest headlines, the continent of Greenland has been experiencing unusual weather this winter, too.

Despite some periods of extreme cold, this winter has been much warmer than average, according to Polar Portal, a website run by Danish researchers. A succession of heavy storms since October dumped more snow than usual on the eastern and southern parts of ice sheet, the scientists explained:

"The accumulation season got off to a flying start in October, when a series of large storms hit the east coast of Greenland, dropping 264mm of rain in the main town of Tasiilaq in 25 days, compared to the average for October of 83mm for the whole of October."

Top: Map of ice mass lost (red) and gained (blue) from the surface of Greenland through snowfall between Sept. 1 2016 and March 20 (in mm water equivalent) Bottom: Change in surface ice mass during winter 2016/17 compared to previous years. Danish Meteorological Institute

But while some claim this extra snowfall over winter means Greenland ice is at "record high" levels, this ignores a much bigger part of the picture. Icebergs "calving" off the ice sheet and into the ocean account for much bigger losses, explained Dr. Ruth Mottram, a researcher at the Danish Meteorological Institute. She told Carbon Brief:

"Over the last decade, Greenland has lost around 200-300bn tonnes (gigatonnes, Gt) of ice each year; the extra snowfall we estimate from our models is about 150Gt. So it's not at all balancing what is lost by melting and calving in a typical year."

The summer months—June, July and August—are the most important for the ice sheet, so it's important not to read too much into heavy snowfall over the winter season, Mottram added.

"Exceptional Year" in the Antarctic

Meanwhile, at the other end of the planet, Antarctic sea ice has been experiencing its minimum extent for the year.

With 2.11m square kilometers of ice, this year's low marks an all-time record low for the satellite era. Reached on March 3, the summer minimum caps off an unusually vigorous melt season, with new records set in every month since November.

Carbon Brief

How does 2017 compare to previous years? Natural fluctuations play a big role in Antarctic climate, causing swings in sea ice extent from year to year. Dr. Mark Brandon, a polar oceanographer at the Open University, told Carbon Brief:

"Just a few years ago the Antarctic sea ice extent was breaking records as being relatively high, but this year it has shown record-breaking lows for several months."

The Antarctic's "exceptional year" in 2017 could even be a hangover from the powerful El Niño the world recently experienced, said Brandon:

"A pattern of air pressure that determines the wind circulation in the high southern latitudes called the Southern Annular Mode switched from positive to negative in late 2016 and this may be linked to the large El Nino of 2014-16."

This switch made the ice "more mobile and likely led to the relatively early Antarctic spring," explained Brandon.

Antarctic sea ice extent for March 3 was 2.11 million square kilometers. The orange line shows the 1981 to 2010 median extent for that day.U.S. National Snow and Ice Data Center

Having passed the summer minimum, sea ice has started growing again. But scientists will be keeping a close eye in coming months to see how the ice fares over the winter freeze up season, explained Prof. John Turner, a climatologist at the British Antarctic Survey. He told Carbon Brief:

"The rate of recovery after March 1 has been a little slow, but not too far off what we see normally. It's just that the amount of ice is about 400,000 square kilometers less than the previous minimum."

Bucking the Trend

Such low ice cover at this time of year is unusual for recent times. Satellites have, in fact, measured a slight increase in Antarctic sea ice over the past 20 years or so, despite rising global temperature. You can see this in the graph below from NSIDC.

A number of factors could be behind this somewhat counterintuitive trend, said Dr. Jonathan Day, an expert in sea-ice prediction at the University of Reading. He told Carbon Brief:

"[The upward trend in Antarctic sea ice] could be a response to human-caused climate changes, such as ozone depletion or freshening of the ocean surface due to melting of land ice, both of which may cause the ice cover to expand."

Evidence also suggests a change in winds driven by a natural cycle in the tropical Pacific Ocean could be behind recent Antarctic sea ice growth, said Day. Prof. Jerry Meehl, a scientist from the National Center for Atmospheric Research and lead author on that research, told Carbon Brief:

"The connection from the tropical Pacific to the Antarctic involves a chain reaction of linked physical processes that ends up with the winds around Antarctica affecting sea ice extent."

If natural variability has been masking the signal of human-caused climate change in the Antarctic over the satellite period, this pattern will reverse at some stage. In fact, it may already have, said Meehl. He told Carbon Brief there is evidence the Pacific cycle "switched" in 2015, which could mean we're seeing the start of a declining trend in Antarctic sea ice.

But the message from scientists is that while Antarctic sea ice appears to be bucking the trend this year, they need more than a single year before they can tell if a long-term change is afoot.

Conclusion

Overall, it has been an exceptional year for the world's ice cover. While Antarctic sea ice has thrown up a few interesting questions for polar scientists, record low levels in the Arctic for this time of year continues the persistent downward trend that characterizes the last three decades.

Reposted with permission from our media associate Carbon Brief.

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63.5º F: Antarctica's New Record High Temp

The World Meteorological Organization announced Wednesday that Antarctica hit a new record high recorded temperature of 63.5 degrees F.

The record, set at an Argentine research base in 2015 and just confirmed by the World Meteorological Organization, breezes past the previous record of 59 degrees.

Meanwhile, real time data released from the National Snow and Ice Data Center showed only 2.131 million square kilometers of sea ice surrounding the continent on Feb. 28—about 159,000 square kilometers less than the record low set in 1997. The Antarctic ice sheet contains 90 percent of the world's freshwater, which would raise sea levels by 200 feet if it were to melt.

For a deeper dive:

Temps: Reuters, USA Today, Gizmodo

Sea ice: Washington Post

Commentary: Forbes, Marshall Shepherd column

For more climate change and clean energy news, you can follow Climate Nexus on Twitter and Facebook, and sign up for daily Hot News.

University of Maine

Temperatures Skyrocket in Arctic, Prompt Desperate 'Refreeze' Plan

Temperature readings near the North Pole soared to 50 degrees F above average on Friday, as a storm pushed warm air into the Arctic region.

Animation of global temperatures including the record warm year of 2016.

This is the third such worryingly warm period this winter and sea ice figures released last week show the lowest January ice extent in satellite record—nearly 500,000 square miles below average.

The situation in the region is so alarming that a team of scientists from Arizona State University have published a plan to "refreeze" the Arctic in the American Geophysical Union's journal Earth's Future. The fact that the $500 billion plan, which would use millions of wind pumps to circulate colder water to the surface of the ice, is even being discussed "reveals just how desperately worried researchers have become about the Arctic," reported the Guardian.

For a deeper dive:

Temperatures: Washington Post, Mashable, Christian Science Monitor

Refreeze: The Guardian

Background: Climate Signals

For more climate change and clean energy news, you can follow Climate Nexus on Twitter and Facebook, and sign up for daily Hot News.

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