Flooded Kingdoms Of The Last Ice Age Pt 1 of 5

What Scientists Are Seeing Over Antarctica

Big trouble in the Antarctic has been brewing for a long time

Big trouble in the Antarctic has been brewing for a long time
David Spratt, 15 June 2014

"A game changer" is how climate scientist Dr Malte Meinshausen describes newly published research that West Antarctic glaciers have passed a tipping point much earlier than expected and their disintegration is now "unstoppable" at just the current level of global warming. The research findings have shocked the scientific community. "This Is What a Holy Shit Moment for Global Warming Looks Like," ran a headline in Mother Jones magazine.

In the Guardian, lead researcher Dr Eric Rignot explained:

We announced that we had collected enough observations to conclude that the retreat of ice in the Amundsen sea sector of West Antarctica was unstoppable, with major consequences – it will mean that sea levels will rise one metre worldwide. What's more, its disappearance will likely trigger the collapse of the rest of the West Antarctic ice sheet, which comes with a sea level rise of between three and five metres. Such an event will displace millions of people worldwide.But this news should not have come as a shock. In 2007 when we wrote "Climate Code Red", Philip Sutton and I devoted a chapter to Antarctica, and surveyed scientists who were warning of this scenario. We quoted NASA climate chief James Hansen:

We find it implausible that BAU [‘business-as-usual’] scenarios, with climate forcing and global warming exceeding those of the Pliocene, would permit a West Antarctic ice sheet of present size to survive even for a century.As far back as 1968, John Mercer had predicted that the collapse of ice shelves along the Antarctic Peninsula could herald the loss of the ice sheet in West Antarctica, and 10 years later contended that: "a major disaster — a rapid deglaciation of West Antarctica — may be in progress … within about 50 years."

Such science was excluded from "mainstream" reports such as those of the IPCC, which systematically and embarrassing underestimated likely sea-level rises, with the most recent, 2013 report being no exception.

It's par for the course for climate policy-makers to hope for the best, rather than plan for the worst. More than once this blog has warned that sea-level rises are being underestimated by Australian policy-makers, and that the tens of millions of dollars being put into adaptation planning for sea-level rises of no more than 1.1 metres by 2100 will be a waste of money, and all that work will have to be done again. And now that has come to pass.

It's so dumb, but putting politics ahead of science has got us into this mess, and there is little sign that even peer-reviewed evidence that West Antarctic has passed a tipping point for partial or total collapse of its ice sheets will get those in power to acknowledge scientific reality.

So here, for the record, is what we said back in late 2007.

Climate Code Red (extract): Antarctica

Big changes are also underway at the other end of the world, in the Antarctic, where most of the world’s ice sits on the fifth largest continent. The majority of Antarctic ice is contained in the East Antarctic ice sheet — the biggest slab of ice on Earth, which has been in place for some 20 million years and which, if fully melted, would raise sea levels by more than 60 metres.

Considered more vulnerable is the smaller West Antarctic ice sheet, which contains one-tenth of the total Antarctic ice volume. If it disintegrated, it would raise sea levels by around 5 metres, a similar amount to what we would see with a total loss of the Greenland ice sheet.

While it was generally anticipated that the West Antarctic sheet would be more stable than Greenland at a 1–2 degree rise, recent research demonstrates that the southern ice shelf reacts far more sensitively to warming temperatures than scientists had previously believed. Ice-core data from the Antarctic Geological Drilling joint project (being conducted by Germany, Italy, New Zealand, and the United States) shows that ‘massive melting’ must have occurred in the Antarctic three million years ago, during the Miocene–Pliocene period, when the average global temperature in the oceans increased by only 2–3 degrees above the present temperature. Geologist Lothar Viereck-Götte called the results ‘horrifying’, and suggested that ‘the ice caps are substantially more mobile and sensitive than we had assumed’.

The heating effect caused by climate change is greatest at the poles, and the air over the West Antarctic peninsula has warmed nearly 6 degrees since 1950. At the same time, according to a report in the Washington Post on 22 October 2007, a warming sea is melting the ice-cap edges, and beech trees and grass are taking root on the ice fringes.

Another warning sign was the rapid collapse in March 2002 of the 200-metre-thick Larsen B ice shelf, which had been stable for at least twelve thousand years, and which was the main outlet for glaciers draining from West Antarctica. An ice shelf is a floating sheet, or platform, of ice. Largely submerged, and up to a kilometre thick, the shelf abuts the land and is formed when glaciers or land-based ice flows into the sea. Generally, an ice shelf will lose volume by calving icebergs, but these are also subject to rapid disintegration events. Larsen B, weakened by water-filled cracks where its shelf attached to the Antarctic Peninsula, gave way in a matter of days, releasing five hundred billion tonnes of ice into the ocean.

Neil Glasser of Aberystwyth University and Ted Scambos from the NSIDC found that as glacier fl ow had begun to increase during the 1990s, the ice shelf had become stressed. The warming of deep Southern Ocean currents (which increasingly reach the Antarctic coastline) had also led to some thinning of the shelf, making it more prone to breaking apart. Scambos concludes that ‘the unusually warm summer of 2002, part of a multi-decade trend of warming [that is] clearly tied to climate change, was the final straw’.

Looking at the overall pace of events, Scambos says: ‘We thought the southern hemisphere climate is inherently more stable, [but] all of the time scales seem to be shortened now. These things can happen fairly quickly. A decade or two of warming is all you need to really change the mass balance … Things are on more of a hair trigger than we thought.’

Much of the West Antarctic ice sheet sits on bedrock that is below sea level, buttressed on two sides by mountains, but held in place on the other two sides by the Ronne and Ross ice shelves; so, if the ice shelves that buttress the ice sheet disintegrate, sea water breeching the base of the ice sheet will hasten the rate of disintegration.

In 1968, the Ohio State University glaciologist John Mercer warned, in the journal of the International Association of Scientific Hydrology, that the collapse of ice shelves along the Antarctic Peninsula could herald the loss of the ice sheet in West Antarctica. A decade later, in 1978, his views received a wider audience in Nature, where he wrote: ‘I contend that a major disaster — a rapid deglaciation of West Antarctica — may be in progress … within about 50 years.’ Mercer said that warming ‘above a critical level would remove all ice shelves, and consequently all ice grounded below sea level, resulting in the deglaciation of most of West Antarctica’. Such disintegration, once under way, would ‘probably be rapid, perhaps catastrophically so’, with most of the ice sheet lost in a century. Credited with coining the phrase ‘the greenhouse effect’ in the early 1960s, Mercer’s Antarctic prognosis was widely ignored and disparaged at the time, but this has changed.

(James Hansen says it was not clear at the time whether Mercer or his many critics were correct, but those who labelled Mercer an alarmist were considered more authoritative and better able to get funding. Hansen believes funding constraints can inhibit scientific criticisms of the status quo. As he wrote in New Scientist on 28 July 2007: ‘I believe there is pressure on scientists to be conservative.’ Hansen is responsible for coining the term ‘The John Mercer Effect’, meaning to play down your findings for fear of losing access to funding or of being considered alarmist.)

Another vulnerable place on the West Antarctic ice sheet is Pine Island Bay, where two large glaciers, Pine Island and Thwaites, drain about 40 per cent of the ice sheet into the sea. The glaciers are responding to rapid melting of their ice shelves and their rate of fl ow has doubled, whilst the rate of mass loss of ice from their catchment has now tripled. NASA glaciologist Eric Rignot has studied the Pine Island glacier, and his work has led climate writer Fred Pearce to conclude that ‘the glacier is primed for runaway destruction’. Pearce also notes the work of Terry Hughes of the University of Maine, who says that the collapse of the Pine Island and Thwaites glaciers — already the biggest causes of global sea-level rises — could destabilise the whole of the West Antarctic ice sheet. Pearce is also swayed by geologist Richard Alley, who says there is ‘a possibility that the West Antarctic ice sheet could collapse and raise sea levels by 6 yards [5.5 metres]’, this century.

Hansen and fellow NASA Goddard Institute for Space Studies researcher Makiko Sato agree:

The gravest threat we foresee starts with surface melt on West Antarctica, and interaction among positive feedbacks leading to catastrophic ice loss. Warming in West Antarctica in recent decades has been limited by effects of stratospheric ozone depletion. However, climate projections find surface warming in West Antarctica and warming of nearby ocean at depths that may attack buttressing ice shelves. Loss of ice shelves allows more rapid discharge from ice streams, in turn a lowering and warming of the ice sheet surface, and increased surface melt. Rising sea level helps unhinge the ice from pinning points … Attention has focused on Greenland, but the most recent gravity data indicate comparable mass loss from West Antarctica. We find it implausible that BAU [‘business-as-usual’] scenarios, with climate forcing and global warming exceeding those of the Pliocene, would permit a West Antarctic ice sheet of present size to survive even for a century.Even in East Antarctica, where total ice loss would produce a sea-level rise of 60 metres, mass loss near the coast is greater than the mass increase inland (mass increase inland is caused by the extra snowfall generated from warming-induced increases in air humidity).

While the inland of East Antarctica has cooled during the last 20 years, the coast has become warmer, with melting occurring 900 kilometres from the coast and in the Transantarctic Mountains, which rise up to an altitude of 2 kilometres.

Research published in January 2008 by Rignot and six of his colleagues shows that ice loss in Antarctica has increased by 75 per cent in the last ten years due to a speed-up in the flow of its glaciers, so that the ice loss there is now nearly a great as that observed in Greenland.

"Rivers of Ice": Vanishing Glaciers of the Greater Himalaya

"Rivers of Ice": Vanishing Glaciers of the Greater Himalaya
Published on Jan 16, 2014
Session from the Aspen Ideas Festival 2012. The Himalaya are home to the world's most magnificent peaks and thousands of high-altitude glaciers. These important glaciers supply crucial seasonal flows to rivers across Asia, yet many are disappearing at an increasing rate. "Rivers of Ice" presents recent photographs by mountaineer and photographer David Breashears of the world's least studied glaciers alongside archival photographs taken over the past century by the world's greatest alpine photographers. The comparison starkly reveals the alarming loss of ice during the intervening years.

Chasing Ice (Arabic sub)

Chasing Ice (Arabic sub)

Weathergirl goes rogue

Weathergirl goes rogue
Published on Sep 3, 2012

Arctic ice cover just reached its lowest point in recorded history. Pippa goes off script and drops some science. For more, check outhttp://www.deeprogueram.tumblr.com
Or Facebook: http://www.facebook.com/pages/Deep-Ro...
Or Twitter: https://twitter.com/deeprogueram

Filmed at Strut Studios in Vancouver: http://www.strutstudios.com/

Starring Pippa Mackie and Kai Nagata. Written by Heather Libby.

Melting Polar Ice Caps A "Ticking Timebomb" For Earth's Climate System

Melting Polar Ice Caps A "Ticking Timebomb" For Earth's Climate System
TheRealNews Published on May 28, 2014

Journalist Dahr Jamail & Professor Peter Wadhams say the resulting release of methane will lead to massive climate disruption, and that we have reached a point of no return

Antarctic Ice Melt Rate Has Doubled Since 2010

A glacial ice shelf seen from the air.

Antarctic Ice Melt Rate Has Doubled Since 2010, Study Finds
ANDREW FREEDMAN May 19, 2014 mashable.com

A European Space Agency satellite has found that Antarctica has been shedding ice at an accelerated pace compared to when the continent was last surveyed, backing up other research that has detected similar trends. The study, accepted for publication in the journal Geophysical Research Letters, comes one week after other studies claimed that the "collapse" of some glaciers in the West Antarctic Ice Sheet may be inevitable, due to manmade global warming and other factors.

The new research, by a team of researchers in the U.K., used observations from the CryoSat-2 satellite to produce the first estimate of the volume and mass change of nearly the entire Antarctic ice sheet. The data used in the study included more than 455,000 independent estimates of changes in the land elevation of the vast ice sheets covering Antarctica, both in the western part of the continent, where ice is melting more rapidly, and in the east, where the ice is considered to be more stable, for the time being at least.

Three years of observations, between 2010 and 2013, from the CryoSat-2 satellite show that the Antarctic ice sheet is now losing about 160 billion metric tons of ice each year –- twice as much as when it was last surveyed during the 2005 to 2010 period.


Recent land elevation changes via the CryoSat-2 satellite, showing the greatest amount of sinking land in West Antarctica.

The CryoSat-2 satellite, which is operated by the European Space Agency, uses high-tech altimeter instruments to detect changes in the height of the ice sheet, and see whether it is gaining or losing mass.

According to the study, the average elevation of the Antarctic ice sheet fell by 0.74 inches per year between 2010 and 2013. However, far more rapid rates of land elevation changes, which are a sign of a thinning ice sheet that is discharging more water into the ocean and thereby raising global sea levels, occurred in West Antarctica, the study found.

In the Amundsen Sea Embayment region of West Antarctica, where glaciers terminate in the ocean and extend over the waters via floating ice tongues, six major glaciers are experiencing rapid rates of retreat. These glaciers are being eaten away from underneath due to warm ocean waters that have been driven toward the continent by shifting wind patterns that have in turn been linked to manmade global warming, as well as natural climate variability. For example, the Smith Glacier has been sinking at nearly 30 feet per year, the Cryosat data showed.

“We find that ice losses continue to be most pronounced along the fast-flowing ice streams of the Amundsen Sea sector, with thinning rates of 4 to 8 meters per year near to the grounding lines –- where the ice streams lift up off the land and begin to float out over the ocean –- of the Pine Island, Thwaites and Smith Glaciers,” said lead author Malcolm McMillan of the University of Leeds in the U.K. in a press release.

Using observations of recent rates of ice loss and model-based projections of the future, two studies published in scientific journals last week found that a slow-motion "collapse" of parts of the West Antarctic Ice Sheet may be inevitable, due in large part to manmade climate change and other factors. This could raise average global sea level by up to 15 feet, inundating highly populated coastal areas around the world.

The new study does not explicitly address that conclusion, but it does underscore the rapid melting that is taking place in the West Antarctic Ice Sheet in particular. In West Antarctica, the satellite data shows a mass loss of about 134 billion metric tons of ice per year, which is 31% greater than over the 2005 to 2011 period.

"Our results are in broad agreement with these previous studies. We detect widespread thinning of this part of the West Antarctic Ice Sheet, which is what you would be expect to see from an ice sheet in a state of irreversible long-term collapse," said Malcolm McMillan, a research fellow at the University of Leeds, in an email to Mashable. "I should add that our study focuses on providing an up-to-date assessment of how the ice sheet has changed in the last 3 years, whereas one of the previous studies... uses models to investigate how the ice sheet may evolve in the future."

East Antarctica is losing a relatively small amount of 3 billion metric tons of ice per year, the study found, and McMillan described that part of Antarctica as "roughly in balance."



Projections of global mean sea level rise over the 21st century, based on different emissions scenarios.

Although the study did not find a significant change in the elevation of the interior East Antarctic Ice Sheet, it shows for the first time that the thinning of the Totten glacier in that region extends to the point where the ice meets the land surface below, known as the grounding line. Overall, the researchers found that West Antarctica, the Antarctic Peninsula and East Antarctica have all been losing mass, albeit at different rates.

The Antarctic Peninsula, which is the fastest-warming region on the continent, has been shedding about 23 billion metric tons of ice per year, the study found. Changes in snowfall amounts have helped balance out some of the ice losses there and especially in eastern Antarctica.

For Antarctica as a whole, the study found the current rate of ice sheet mass loss to be about 160 billion metric tons of ice per year. The extra water pouring into the sea is raising sea levels by about 0.1 inches per year, the study found.

That may seem small at first, but over time, especially when combined with other sources of sea level rise such as melting Greenland glaciers and the expansion of seawater as ocean temperatures increase, it adds up. In addition, there are no guarantees that the current rate will be maintained, since many studies have shown the likelihood of a higher rate of sea level rise as global warming continues.

"Antarctica is contributing more to sea level rise than previous measurements suggested. It is essential that we continue to monitor the ice sheet to understand how, and why, it is changing," McMillan said. While the study only includes data for the past three years, the observations extend a longer satellite record that dates back to the early 1990s, McMillan said. This data helps scientists make conclusions about how Antarctica's ice sheets are changing.

The most recent report from the U.N. Intergovernmental Panel on Climate Change projected a global average sea level rise of between about one to three feet, although that report did not take the new findings on Antarctic ice melt into account.

West Antarctic Ice Sheet collapse is under way May 12, 2014

This is a photo of the Thwaites ice shelf taken during an October 2013 Operation IceBridge aerial survey.

West Antarctic Ice Sheet collapse is under way
May 12, 2014 phys.org

The West Antarctic Ice Sheet, which holds enough water to raise global seas by several feet, is thinning. Scientists have been warning of its collapse, based on theories, but with few firm predictions or timelines.

University of Washington researchers used detailed topography maps and computer modeling to show that the collapse appears to have already begun. The fast-moving Thwaites Glacier will likely disappear in a matter of centuries, researchers say, raising sea level by nearly 2 feet. That glacier also acts as a linchpin on the rest of the ice sheet, which contains enough ice to cause another 10 to 13 feet (3 to 4 meters) of global sea level rise. The study will be published on May 16 in Science.

"There's been a lot of speculation about the stability of marine ice sheets, and many scientists suspected that this kind of behavior is under way," said Ian Joughin, a glaciologist at the UW's Applied Physics Laboratory. "This study provides a more quantitative idea of the rates at which the collapse could take place."

The good news is that while the word "collapse" implies a sudden change, the fastest scenario is 200 years, and the longest is more than 1,000 years. The bad news 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," Joughin said. "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."

This is a high-resolution map of Thwaites Glacier's thinning ice shelf. Warm circumpolar deep water is melting the underside of this floating shelf, leading to an ongoing speedup of Thwaites Glacier. This glacier now appears to be in the early stages of collapse, with full collapse potentially occurring within a few centuries. Collapse of this glacier would raise global sea level by several tens of centimeters, with a total rise by up to a few meters if it causes a broader collapse of the West Antarctic Ice Sheet. Credit: David Shean / Univ. of Washington

Earlier warnings of collapse had been based on a simplified model of ice sitting in an inward-sloping basin. The topography around Antarctica, however, is complex. The new study used airborne radar, developed at the University of Kansas with funding from the National Science Foundation, to image through the thick ice and map the topography of the underlying bedrock, whose shape controls the ice sheet's long-term stability. The mapping was done as part of NASA's Operation IceBridge, and included other instruments to measure the height of the ice sheet's rapidly thinning surface. In some places Thwaites Glacier has been losing tens of feet, or several meters, of elevation per year.

UW researchers combined that data with their own satellite measurements of ice surface speeds. Their computer model was able to reproduce the glacier's ice loss during the past 18 years, and they ran the model forward under different amounts of ocean-driven melting. The place where the glacier meets land, the grounding line, now sits on a shallower ridge with a depth of about 2,000 feet (600 meters). Results show that as the ice edge retreats into the deeper part of the bay, the ice face will become steeper and, like a towering pile of sand, the fluid glacier will become less stable and collapse out toward the sea.

"Once it really gets past this shallow part, it's going to start to lose ice very rapidly," Joughin said.

The study considered future scenarios using faster or slower melt rates depending on the amount of future warming. The fastest melt rate led to the early stages lasting 200 years, after which the rapid-stage collapse began. The slowest melt rate kept most of the ice for more than a millennium before the onset of rapid collapse. The most likely scenarios may be between 200 and 500 years, Joughin said.

"All of our simulations show it will retreat at less than a millimeter of sea level rise per year for a couple of hundred years, and then, boom, it just starts to really go," Joughin said.

Researchers did not model the more chaotic rapid collapse, but the remaining ice is expected to disappear within a few decades.

The thinning of the ice in recent decades is most likely related to climate change, Joughin said. More emissions would lead to more melting and faster collapse, but other factors make it hard to predict how much time we could buy under different scenarios.

Graphic: Outlook for Arctic Ice

Stefan Rahmstorf -- The Climate Crisis

Stefan Rahmstorf -- The Climate Crisis
Published on Feb 11, 2014
In his lecture "The Cimate Crisis", professor Stefan Rahmstorf explains how, since the start of the industrial age, the carbon dioxide content of the atmosphere has risen to the by far highest value of the last million years. At the same time, global average surface temperatures have increased by 0.8°C. This warming is continuing unabated: 2010 was, followed by 2005, the hottest year on record since global measurements began more than 130 years ago. The ice cover on the Arctic Ocean is shrinking rapidly and reached a record low value in September 2012. The huge ice sheets both in Greenland and Antarctica are losing mass at an increasing rate, as satellite data show. This contributes to the accelerating rise of sea levels, which rose at a rate of one centimeter per decade at the beginning of the 20th Century, but have been rising at over three centimeters per decade for the past twenty years. The last decade has witnessed a sequence of unprecedented weather extremes, including the 2010 Russian heat wave, the flooding in Pakistan that same year, and the 2012 summer heat wave in the US. To prevent unmanageable climate change, humanity can still limit global warming to a maximum of 2°C -- but only if decisive and rapid action is taken to transform our energy system.

The lectures shared here were given on October 5th 2013 in the following order:

Guðni Elísson: "Earth101"
Stefan Rahmstorf: "The Climate Crisis"
Michael Mann: "The Hockey Stick and the Climate Wars"
Kari Norgaard: "Living in Denial: Climate Change, Emotions and Everyday Life"
Peter Sinclair: "Communicating Climate Science in the Disinformation Era"
Recorded by Phil Coates and edited by Ryan Chapman.

Earth Ice Age Era's

Earth Ice Age Era's
Published on Dec 12, 2013
A look at past Ice Age eras that Earth has experienced throughout its existence; how the slightest changes in the planet's orbit and angle of rotation can bring them about; how long they can last, and when the Earth will endure another.

An ice age, or more precisely, a glacial age, is a period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Within a long-term ice age, individual pulses of cold climate are termed "glacial periods" (or alternatively "glacials" or "glaciations" or colloquially as "ice age"), and intermittent warm periods are called "interglacials". Glaciologically, ice age implies the presence of extensive ice sheets in the northern and southern hemispheres. By this definition, we are still in the ice age that began 2.6 million years ago at the start of the Pleistocene epoch, because the Greenland, Arctic, and Antarctic ice sheets still exist.

There are three main types of evidence for ice ages: geological, chemical, and paleontological.

Geological evidence for ice ages comes in various forms, including rock scouring and scratching, glacial moraines, drumlins, valley cutting, and the deposition of till or tillites and glacial erratics. Successive glaciations tend to distort and erase the geological evidence, making it difficult to interpret. Furthermore, this evidence was difficult to date exactly; early theories assumed that the glacials were short compared to the long interglacials. The advent of sediment and ice cores revealed the true situation: glacials are long, interglacials short. It took some time for the current theory to be worked out.

The chemical evidence mainly consists of variations in the ratios of isotopes in fossils present in sediments and sedimentary rocks and ocean sediment cores. For the most recent glacial periods ice cores provide climate proxies from their ice, and atmospheric samples from included bubbles of air. Because water containing heavier isotopes has a higher heat of evaporation, its proportion decreases with colder conditions. This allows a temperature record to be constructed. However, this evidence can be confounded by other factors recorded by isotope ratios.

The paleontological evidence consists of changes in the geographical distribution of fossils. During a glacial period cold-adapted organisms spread into lower latitudes, and organisms that prefer warmer conditions become extinct or are squeezed into lower latitudes. This evidence is also difficult to interpret because it requires (1) sequences of sediments covering a long period of time, over a wide range of latitudes and which are easily correlated; (2) ancient organisms which survive for several million years without change and whose temperature preferences are easily diagnosed; and (3) the finding of the relevant fossils.

Despite the difficulties, analysis of ice core and ocean sediment cores[citation needed] has shown periods of glacials and interglacials over the past few million years. These also confirm the linkage between ice ages and continental crust phenomena such as glacial moraines, drumlins, and glacial erratics. Hence the continental crust phenomena are accepted as good evidence of earlier ice ages when they are found in layers created much earlier than the time range for which ice cores and ocean sediment cores are available.

In 1742 Pierre Martel (1706--1767), an engineer and geographer living in Geneva, visited the valley of Chamonix in the Alps of Savoy. Two years later he published an account of his journey. He reported that the inhabitants of that valley attributed the dispersal of erratic boulders to the fact that the glaciers had once extended much farther. Later similar explanations were reported from other regions of the Alps. In 1815 the carpenter and chamois hunter Jean-Pierre Perraudin (1767--1858) explained erratic boulders in the Val de Bagnes in the Swiss canton of Valais as being due to glaciers previously extending further. An unknown woodcutter from Meiringen in the Bernese Oberland advocated a similar idea in a discussion with the Swiss-German geologist Jean de Charpentier (1786--1855) in 1834. Comparable explanations are also known from the Val de Ferret in the Valais and the Seeland in western Switzerland and in Goethe's Scientific Work. Such explanations could also be found in other parts of the world. When the Bavarian naturalist Ernst von Bibra (1806--1878) visited the Chilean Andes in 1849--1850 the natives attributed fossil moraines to the former action of glaciers.

Abrupt Climate Change In The Arctic (And Beyond)

Abrupt Climate Change In The Arctic (And Beyond) An Update
Published on Dec 21, 2013
AGU Fall Meeting 2013

Our understanding of future Arctic change is informed by the history of past changes, which often have been both large and abrupt. The well-known ice-age events such as the Younger Dryas show how sea-ice changes can amplify forcing to produce very large responses, with wintertime sea ice especially important. These changes are increasingly seen to have played a central role in the ice-age cycling through their global impact on CO2 storage in the deep ocean.

The Heinrich events reveal processes of ice-sheet/ocean interaction, some of which are being played out in Greenland and Antarctica now, and which may have large future effects on sea-level rise. The paleoclimatic record plus physical understanding greatly reduce the worst worries about instabilities from methane stored in cold places, but tend to support a role in amplifying future warming.

Overall, the very large impacts of past Arctic changes, and the likelihood that future changes under business-as-usual fossil-fuel emissions will be unprecedented in combined size and speed, raise important questions.

The melting polar icecap is creating waves the size of houses

The melting polar icecap is creating waves the size of houses
By Gwynn Guilford, April 29, 2014

Compared with the monster seas of the Pacific, Arctic waters are a picture of calm—whipping up, at their most violent, into lake-like chop. Or, at least, they were. New research shows that something is whipping up waves that reach five meters (16.4 feet).

“That’s a big wave—that’s a house-sized wave. And that has never been observed before in the Arctic,” says Jim Thomson, a physicist at the University of Washington who led the study (paywall).

So why is it happening now? “As the ice retreats in the Arctic, which it is doing in a very remarkable way, we’re finding more and more waves,” says Thomson. “And we’re finding a very direct relationship between the height of the waves and the retreat of the ice.”

He’s talking about the sheet of ice that blankets the Arctic, which melts a bit in the summer and re-freezes throughout winter. Toward the end of the last century, the summer sun typically peeled it back at most 100 kilometers (62 miles) from the coast. Now the edge of the Arctic ice cover recedes thousands of kilometers.

Every summer, in other words, the planet gets a whole new ocean. And with a new ocean comes new waves, it turns out.

Wind is the major force creating waves. While it makes smaller waves locally, swells—those big, rolling waves that can rear up out of the sea in storms—come from much further away. That explains why, until recently, the Arctic had whitecaps, but no swells. But the polar icecap’s recent peel-back is opening up the huge spans of water needed to make waves big.

Take, for instance, the Beaufort Sea that skirts northern Alaska, which Thomson and his colleague Erick Rogers were researching. As late as April, that gap between the north pole and Alaska is completely blanketed in ice, and whereas it once retreated hundreds of kilometers each summer, now the ice disappears almost entirely. That’s why heavy winds in September 2012 kicked up these waves:


​

This is worrisome for a couple of reasons. First, there’s simply safety. The new Arctic waterway is exciting to commercial shipping companies, which see it offering a shorter trade route. China, for example, estimates that by 2020, up to $500 billion worth of its trade could transit through the new waterway.


New transit routes opening up for two major vessel types: current routes (left) vs. those possible in 2050 (right). Smith and Stephenson, PNAS, Early Edition

The tradeoff, as Thomson and Rogers’ research suggests, is that more open sea means bigger waves—and more risk of danger. Between 2009 and 2013, the annual average of ships lost or severely damaged (pdf, p.3) in Arctic waters rose to 45, up from the 2002-7 average of seven ships, according to Allianz. And if the Arctic starts looking more like the rest of the ocean, that could get worse; storms caused three-quarters of all shipping losses last year, reports Allianz.

More ominous still is that the emergence of big swells is very likely accelerating the disappearance of Arctic ice. Swells carry much more energy. The force they deliver when they slam into the icecap breaks off floes, hastening the retreat—and creating ever-bigger swells.

On top of that, the huge amounts of foam created by big waves flushes more carbon dioxide from the atmosphere into the ocean, says Thomson. Though scientists aren’t clear how those gases get dissolved, that’s going to shake up Arctic chemistry in a way that is hard to anticipate.

Above the Earth, documentary on climate change

Above the Earth, documentary on climate change
Published on Jul 24, 2013
Climate Change

Glacier lakes: Growing danger zones in the Himalayas

Glacier lakes: Growing danger zones in the Himalayas
Ken Macfarlane and Suzanne Goldenberg
11 October 2011 theguardian.com Length: 4min 03sec
Source: Guardian/Dan Byers and Mountain Institute

Fears rise of huge outburst flooding in the Himalayas as glaciers melt due to climate change
Suzanne Goldenberg talks to local people and scientists about the threat posed by Lake Imja, a vast lake 5,100m high in the Himalayas that is being formed as glaciers melt

BBC Earth The Power Of The Planet - Ice

BBC Earth The Power Of The Planet - Ice
Uploaded on Sep 18, 2011

What Scientists Are Seeing Over Antarctica

What Scientists Are Seeing Over Antarctica
Published on Dec 1, 2012
NASA's Operation IceBridge has launched its Antarctic 2012 campaign, flying high-priority missions measuring polar ice from a base of operations at the tip of Patagonia on the Strait of Magellan. They have even made a return visit to the Pine Island Glacier, the site of last year's discovery of a massive rift in the ice.

Sea ice doesn't always hold the allure of a massive ice sheet, or a crevassed blue glacier spilling between mountains, but it comes in array of shapes and sizes and has its own ephemeral beauty. Operation IceBridge studies sea ice at both poles, and also runs across interesting formations on route to other targets. Operation IceBridge returned to the Pine Island Glacier twice in 2012, and NASA glaciologist Kelly Brunt discusses the implications of the glacier's impending calving event.

Operation IceBridge has now returned to the Pine Island Glacier, not once, but twice in 2012. And the year-old giant crack in the glacier, poised to create an iceberg the size of New York City? Well it's still there, and that iceberg has yet to break free. But the rift has grown longer, much wider, and spawned a secondary crack. Before we talk about when that mighty berg will be born, let's take a look at the IceBridge missions themselves. IceBridge's first return to the region was a high altitude flight over the entire region, including the Thwaites, Smith, and Kohler glaciers. After this campaign is over, scientists will be able to compare this broad survey with previous years' measurements in order to better document the rapid and widespread changes in the region over time.

Earth in 1000 Years

Earth in 1000 Years
Published on Oct 4, 2013
This edition of COSMIC JOURNEYS explores the still unfolding story of Earth's past and the light it sheds on the science of climate change today. While that story can tell us about the mechanisms that can shape our climate. it's still the unique conditions of our time that will determine sea levels, ice coverage, and temperatures.

Ice, in its varied forms, covers as much as 16% of Earth's surface, including 33% of land areas at the height of the northern winter. Glaciers, sea ice, permafrost, ice sheets and snow play an important role in Earth's climate. They reflect energy back to space, shape ocean currents, and spawn weather patterns.

But there are signs that Earth's great stores of ice are beginning to melt. To find out where Earth might be headed, scientists are drilling down into the ice, and scouring ancient sea beds, for evidence of past climate change. What are they learning about the fate of our planet... a thousand years into the future and even beyond?

30,000 years ago, Earth began a relentless descent into winter. Glaciers pushed into what were temperate zones. Ice spread beyond polar seas. New layers of ice accumulated on the vast frozen plateau of Greenland. At three kilometers thick, Greenland's ice sheet is a monumental formation built over successive ice ages and millions of years. It's so heavy that it has pushed much of the island down below sea level. And yet, today, scientists have begun to wonder how resilient this ice sheet really is.

Average global temperatures have risen about one degree Celsius since the industrial revolution. They could go up another degree by the end of this century. If Greenland's ice sheet were to melt, sea levels would rise by over seven meters. That would destroy or threaten the homes and livelihoods of up to a quarter of the world's population.

With so much at stake, scientists are monitoring Earth's frozen zones... with satellites, radar flights, and expeditions to drill deep into ice sheets. And they are reconstructing past climates, looking for clues to where Earth might now be headed... not just centuries, but thousands of years in the future.

Periods of melting and freezing, it turns out, are central events in our planet's history.
That's been born out by evidence ranging from geological traces of past sea levels... the distribution of fossils... chemical traces that correspond to ocean temperatures, and more.

Going back over two billion years, earth has experienced five major glacial or ice ages. The first, called the Huronian, has been linked to the rise of photosynthesis in primitive organisms. They began to take in carbon dioxide, an important greenhouse gas. That decreased the amount of solar energy trapped by the atmosphere, sending Earth into a deep freeze.

The second major ice age began 580 million years ago. It was so severe, it's often referred to as "snowball earth." The Andean-Saharan and the Karoo ice ages began 460 and 360 million years ago. Finally, there's the Quaternary... from 2.6 million years ago to the present. Periods of cooling and warming have been spurred by a range of interlocking factors: the movement of continents, patterns of ocean circulation, volcanic events, the evolution of plants and animals.

The world as we know it was beginning to take shape in the period from 90 to 50 million years ago. The continents were moving toward their present positions. The Americas separated from Europe and Africa. India headed toward a merger with Asia. The world was getting warmer. Temperatures spiked roughly 55 million years ago, going up about 5 degrees Celsius in just a few thousand years. CO2 levels rose to about 1000 parts per million compared to 280 in pre-industrial times, and 390 today.

But the stage was set for a major cool down. The configuration of landmasses had cut the Arctic off from the wider oceans. That allowed a layer of fresh water to settle over it, and a sea plant called Azolla to spread widely. In a year, it can soak up as much as 6 tons of CO2 per acre. Plowing into Asia, the Indian subcontinent caused the mighty Himalayan Mountains to rise up. In a process called weathering, rainfall interacting with exposed rock began to draw more CO2 from the atmosphere... washing it into the sea. Temperatures steadily dropped.

By around 33 million years ago, South America had separated from Antarctica. Currents swirling around the continent isolated it from warm waters to the north. An ice sheet formed. In time, with temperatures and CO2 levels continuing to fall, the door was open for a more subtle climate driver. It was first described by the 19th century Serbian scientist, Milutin Milankovic.

He saw that periodic variations in Earth's rotational motion altered the amount of solar radiation striking the poles. In combination, every 100,000 years or so, these variations have sent earth into a period of cool temperatures and spreading ice.

Iceberg Twice The Size Of Atlanta

Iceberg Twice The Size Of Atlanta
Published on Apr 22, 2014

A massive iceberg with an area almost twice the size of Atlanta is moving into the ocean off Antarctica and could threaten shipping during the Antarctic winter, scientists say.

The ice island, known as iceberg B31, covers 255 square miles and could be almost a third of a mile thick, scientists say in a report from NASA's Earth Observatory.

The iceberg calved from Antarctica's Pine Island Glacier last November, according to NASA. The crack that produced it was first spotted in 2011.

Since November, B31 has drifted out of Pine Island Bay and into the
Amundsen Sea off the western side of the continent.

"The iceberg is now well out of Pine Island Bay and will soon join the more general flow in the Southern Ocean, which could be east or west in this region," iceberg researcher Grant Bigg from the University of Sheffield in England said in the NASA statement.

Once that happens, the researchers worry it will be difficult track the iceberg during the long weeks of darkness that comprise the Antarctic winter.

And don't expect it to melt. An iceberg of that size could hang around for a year or more, Robert Marsh, a scientist at the University of Southampton in England, said last year.

The largest iceberg ever recorded was called B15. With an area of 4,250 square miles -- about the size of the state of Connecticut or the island of Jamaica -- it calved off Antarctica's Ross Ice Shelf in March 2000. B15 has since broken up, but parts of it still exist around the Antarctic today.