Climate science tells us the alarm bells are ringing

by Michael Oppenheimer and Kevin Trenberth, op-ed, The Washington Post, June 7, 2013

Michael Oppenheimer is a professor of geosciences and international affairs at Princeton University. Kevin Trenberth is a distinguished senior scientist at the National Center for Atmospheric Research.

In a recent op-ed for The Post, Rep. Lamar Smith (R-Tex.) offered up a reheated stew of isolated factoids and sweeping generalizations about climate science to defend the destructive status quo. We agree with the chairman of the House Committee on Science, Space and Technology that policy should be based on sound science. But Smith presented political talking points, and none of his implied conclusions is accurate.

The two of us have spent, in total, more than seven decades studying Earth’s climate, and we have joined hundreds of top climate scientists to summarize the state of knowledge for the Intergovernmental Panel on Climate Change (IPCC), the World Climate Research Program and other science-based bodies. We believe that our views are representative of the97 percent of climate scientists who agree that global warming is caused by humans. Legions of studies support the view that, left unabated, this warming will produce dangerous effects. (This commentary, like so much of our work, was a collaborative process, with input from leading climate scientists Julia Cole, Robert W. Corell, Jennifer Francis, Michael E. Mann, Jonathan Overpeck, Alan Robock, Richard C.J. Somerville and Ben Santer.)

Man-made heat-trapping gases are warming our planet and leading to increases in extreme weather events. Droughts are becoming longer and deeper in many areas. The risk of wildfires is increasing. The year 2012, the hottest on record for the United States, illustrated this risk with severe, widespread drought accompanied byextensive wildfires.

Last month, levels of carbon dioxide in the atmosphere exceeded 400 parts per million, approaching the halfway mark between preindustrial amounts and a doubling of those levels. This doubling is expected to cause a warming this century of four to seven degrees Fahrenheit. The last time atmospheric carbon dioxide reached this level was more than 3 million years ago, when Arctic lands were covered with forests. The unprecedented rate of increase has been driven entirely by human-produced emissions.

Projections from an array of scientific analyses summarized by the National Academy of Sciences and most of the world’s major scientific organizations indicate that by the end of this century, people will be experiencing higher temperatures than any known during human civilization — temperatures that our societies, crops and ecosystems are not adapted to.

Computer model projections from at least 27 groups at universities and other research institutes in nine countries have proved solid. In many cases, they have been too conservative, underestimating over the past 20 years the amounts of recent sea-level rise and Arctic sea ice melt.

Much has been made of a short-term reduction in the rate of atmospheric warming. But “global” warming requires looking at the entire planet. While the increase in atmospheric temperature has slowed, ocean warming rose dramatically after 2000. Excess heat is being trapped in Earth’s climate system, and observations of the Global Climate Observing System and others are increasingly able to locate it. Simplistic interpretations of cherry-picked data hide the realities.

In recent years, our understanding of the relationship between climate and extreme weather has sharpened, along with our appreciation of the vast damages such events cause.

Contrary to Smith’s assertions, there is conclusive evidence that climate change worsened the damage caused by Superstorm Sandy. Sea levels in New York City harbors have risen by more than a foot since the beginning of the 20th century. Had the storm surge not been riding on higher seas, there would have been less flooding and less damage. Warmer air also allows storms such as Sandy to hold more moisture and dump more rainfall, exacerbating flooding.

Smith referred to the IPCC’s special report on extremes but did not mention that the report connects several types of extreme weather to climate change, including heat waves, extreme precipitation and, in some regions, drought. Furthermore, the last major IPCC report, in 2007, stated unequivocally that Earth is warming.

While we are addressing science here, one broad policy implication is clear: Humans must reduce their greenhouse gas emissions. Since John Tyndall discovered in 1859 that carbon dioxide and other greenhouse gases cause warming, science has made great strides toward establishing the scope of that warming and its impact.

The combined impetus of observed trends in climate and weather extremes, and continuing discoveries in climate science, lay bare how ludicrous Smith’s suggestion is that since we know nothing, we should do nothing.

We know a lot, more than enough to recognize that the alarm bells are ringing.

Increases in heat waves and record high temperatures; record lows in Arctic sea ice; more severe rainstorms, droughts and wildfires; and coastal communities threatened by rising seas all offer a preview of the new normal in a warmer world. Smith’s policy plan amounts to “wait and see.” But the longer we wait — effectively, like him, closing our eyes to science — the more difficult and expensive the solutions become, and the more irreversible the damage will be.

http://www.washingtonpost.com/opinions/climate-science-tells-us-the-alarm-bells-are-ringing/2013/06/07/ca81cb84-cef6-11e2-8845-d970ccb04497_story.html

Politico: Did climate change contribute to Sandy? Yes

by Drs. Bob Corell, Jeff Masters and Kevin Trenberth, Politico, November 5, 2012

As Hurricane Sandy battered the East Coast this week, meteorologists and climate scientists were repeatedly asked to explain what role climate change played in amplifying the storm.

We did our best to answer: We know that a warming climate puts more energy into storms, including hurricanes, loading them with more rainfall and the stronger winds pushing more of a storm surge. That makes flooding more likely. We also know that storm surge now rides higher on sea levels that have risen over the last century due to global warming, amplifying losses where the surge strikes. On the stretch of the Atlantic Coast that spans from Norfolk to Boston, sea levels have been rising four times faster than the global average.

Overall, we know that climate change has stacked the deck so that this kind of event happens more frequently. That answer, however, prompts a deeper, more unsettling question that many want to know: is climate change worsening some recent extreme weather events like super storm Sandy?

The short answer is yes. Climate scientists broadly agree that the extreme weather we’ve seen over the past few years is exactly what we’d expect to see in a changing climate. And it’s not just Sandy; we’re on track to have the hottest year in more than a century of record-keeping in the continental United States, the country has suffered one of the most crippling droughts in history, as well as one of the worst wildfire years in history. Last year, when Hurricane Irene hit the United States, meteorologists called it “unprecedented,” yet Sandy has already outpaced the damage from Irene.

We’ll probably never know the exact point when the weather stopped being entirely natural. But we should consider Sandy—and other recent extreme weather events – an early taste of a climate-changed world, and a grim preview of the even worse to come, particularly if we continue to pump more carbon pollution from smokestacks and tailpipes up into the atmosphere.

Last weekend, millions of Americans prepared for the storm by turning to meteorologists to tell them where the storm would hit. The meteorologists relied on detailed computer models to form an accurate prediction of where it would hit and how strong it would be.

We climate scientists use models too, and our results are remarkably consistent and remarkably dire. For example, our models predicted an increase in extreme precipitation with global warming, and that’s exactly what we have witnessed. In the northeast U.S. extreme precipitation has gone up 67 percent in recent years, due to the same rain-loading action that pumped up both Sandy and Hurricane Irene. Our models also predicted more heat waves, and again that’s exactly what we have gotten as the most extreme summers are now much more frequent around the world, setting the stage for intense heat waves.

This new world is expensive – damage from Sandy will be in the billions of dollars, with estimates as high as $50 billion. In 2011, the United States broke a record for the most billion dollar weather disasters in one year, fourteen, totaling $47 billion dollars.

It’s time to stop asking when climate change will arrive. It’s here, and we need to move aggressively to curb carbon emissions while also preparing for a changed world. We are at nothing less than a critical juncture.

In addition to more extreme weather, failing to change our ways will mean extreme costs. Not acting on climate change could cost our nation more than 1 percent of GDP by 2025, or $218 billion a year, according to an analysis by Frank Ackerman, an economist at Tufts University. And it skyrockets from there, possibly to an estimated $1.8 trillion by 2100.

Fortunately, scientists have outlined what is needed to meet this challenge. We need to cut industrial carbon pollution. There are several ways to achieve that goal, many of them also money-savers, and as scientists we stand ready to help policymakers figure out the best, most cost-effective ways to do so.

Dr. Bob Corell is a senior policy fellow for the American Meteorological Society and former Chair of the United States Global Change Research Program.

Dr. Jeff Masters is the founder and Director of Meteorology for Weather Underground and a former NOAA Hurricane Hunter.

Dr. Kevin Trenberth is a Distinguished Senior Scientist in the Climate Analysis Section at the National Center for Atmospheric Research.

Permafrost melt shows significant acceleration in last 5 years, Siberia, Arctic Sea coast, leaking methane (Sergey Zimov, Katey Walter Anthony, Robert Corell)

As Siberia's thawing permafrost leaks methane, some see another emerging climate threat

by  Arthur Max, Associated Press, November 21, 2010

CHERSKY, Russia (AP) -- The Russian scientist shuffles across the frozen lake, scuffing aside ankle-deep snow until he finds a cluster of bubbles trapped under the ice. With a cigarette lighter in one hand and a knife in the other, he lances the ice like a blister. Methane whooshes out and bursts into a thin blue flame.

Gas locked inside Siberia's frozen soil and under its lakes has been seeping out since the end of the last ice age 10,000 years ago. But in the past few decades, as the Earth has warmed, the icy ground has begun thawing more rapidly, accelerating the release of methane -- a greenhouse gas 23 times more powerful than carbon dioxide -- at a perilous rate.

Some scientists believe the thawing of permafrost could become the epicenter of climate change. They say 1.5 trillion tons of carbon, locked inside icebound earth since the age of mammoths, is a climate time bomb waiting to explode if released into the atmosphere.

"Here, total carbon storage is like all the rain forests of our planet put together," says the scientist, Sergey Zimov -- "here" being the endless sweep of snow and ice stretching toward Siberia's gray horizon, as seen from Zimov's research facility nearly 350 kilometers (220 miles) above the Arctic Circle.

Climate change moves back to center-stage on Nov. 29, 2010, when governments meet in Cancun, Mexico, to try again to thrash out a course of counteractions. But U.N. officials hold out no hope the two weeks of talks will lead to a legally binding accord governing carbon emissions, seen is the key to averting what is feared might be a dramatic change in climate this century.

Most climate scientists, with a few dissenters, say human activities -- the stuff of daily life like driving cars, producing electricity or raising cattle -- is overloading the atmosphere with carbon dioxide, methane and other gases that trap heat, causing a warming effect. 

But global warming is amplified in the polar regions. What feels like a modest temperature rise is enough to induce Greenland glaciers to retreat, Arctic sea ice to thin and contract in summer, and permafrost to thaw faster, both on land and under the seabed.

Yet awareness of methane leaks from permafrost is so new that it was not even mentioned in the seminal 2007 report by the Intergovernmental Panel on Climate Change, which warned of rising sea levels inundating coastal cities, dramatic shifts in rainfall disrupting agriculture and drinking water, the spread of diseases and the extinction of species.

"In my view, methane is a serious sleeper out there that can pull us over the hump," said Robert Corell, an eminent U.S. climate change researcher and Arctic specialist. Corell, speaking by telephone from a conference in Miami, said he and other U.S. scientists are pushing Washington to deploy satellites to gather more information on methane leaks.

The lack of data over a long period of time casts uncertainty over the extent of the threat. An article last August in the journal Science quoted several experts as saying it's too early to predict whether Arctic methane will be the tipping point.

"Arctic Armageddon Needs More Science, Less Hype," was its headline.

Studies indicate that cold-country dynamics on climate change are complex. The Arctic Monitoring and Assessment Program, a scientific body set up by the eight Arctic rim countries, says overall the Arctic is absorbing more carbon dioxide than it releases.

"Methane is a different story," said its 2009 report. The Arctic is responsible for up to 9% of global methane emissions. Other methane sources include landfills, livestock and fossil fuel production.

Katey Walter Anthony, of the University of Alaska-Fairbanks, has been measuring methane seeps in Arctic lakes in Alaska, Canada and Russia, starting here around Chersky 10 years ago.

She was stunned to see how much methane was leaking from holes in the sediment at the bottom of one of the first lakes she visited. "On some days it looked like the lake was boiling," she said. Returning each year, she noticed this and other lakes doubling in size as warm water ate into the frozen banks.

"The edges of the lake look like someone eating a cookie. The permafrost gets digested in the guts of the lake and burps out as methane," she said in an interview in Amsterdam, the Netherlands, en route to a field trip in Greenland and Scandinavia.

More than 50 billion tons could be unleashed from Siberian lakes alone, more than 10 times the amount now in the atmosphere, she said.

But the rate of defrosting is hard to assess with the data at hand.

"If permafrost were to thaw suddenly, in a flash, it would put a tremendous amount of carbon in the atmosphere. We would feel temperatures warming across the globe. And that would be a big deal," she said. But it may not happen so quickly. "Depending on how slow permafrost thaws, its effect on temperature across the globe will be different," she said.

Permafrost is defined as ground that has stayed below freezing for more than two consecutive summers. In fact, most of Siberia and the rest of the Arctic, covering one-fifth of the Earth's land surface, have been frozen for millennia.

During the summer, the ground can defrost to a depth of several feet, turning to sludge and sometimes blossoming into vast fields of grass and wildflowers. 

Below that thin layer, however, the ground remains frozen, sometimes encased in ice dozens or even hundreds of meters (yards) thick.

As the Earth warms, the summer thaw bites a bit deeper, awakening ice-age microbes that attack organic matter -- vegetation and animal remains -- buried where oxygen cannot reach, producing methane that gurgles to the surface and into the air.

The newly released methane adds to the greenhouse effect, trapping yet more heat which deepens the next thaw, in a spiraling cycle of increasing warmth.

Curbing man-made methane emissions could slow this process, said Walter Anthony.

"We have an incentive to reduce our fossil fuel emissions. By doing so, we can reduce the warming that's occurring in the Arctic and potentially put some brakes on permafrost thaw," she said.

The U.S. National Oceanic and Atmospheric Administration, in its 2010 Arctic Report Card issued last month, said the average temperature of the permafrost has been rising for decades, but noted "a significant acceleration" in the last five years at many spots on the Arctic coast.

One of those spots would be Chersky, an isolated town on the bank of the Kolyma River at the mouth of the East Siberia Sea.

The ground in this remote corner of the world, 6,600 kilometers (4,000 miles) east of Moscow, has warmed about 2 °C (3.6 °F) in the last five years, to about -5 °C (23 °F), today, says Zimov, director of the internationally funded Northeast Science Station, which is about three kilometers (2 miles) from town.

The warming is causing the landscape to buckle under his feet.

"I live here more than 30 years. ... There are many (dirt) roads in our region which I used or built myself, but now I can't use anymore. Now they look like canyons," he says.

Buildings, too, collapse. The school in Chersky, a Soviet-era structure with a tall bronze statue of Karl Marx on its doorstep, was abandoned several years ago when the walls began to crack as the foundations gave way.

The northern Siberian soil, called yedoma, covers 1.8 million square kilometers (700,000 sq. miles) and is particularly unstable. Below the surface are vertical wedges of ice, as if 15-story-high icicles had been hammered into the soft ground, rich in decaying vegetation, over thousands of years.

As the air warms, the tops of the wedges melt and create depressions in the land. Water either forms a lake or runs off to lower ground, creating a series of steep hillocks and gullies. During summer, lakeside soil may erode and tumble into the water, settling on the bottom where bacteria eat it and cough up yet more methane.

The process takes a long time, but Zimov has done a simulation by bulldozing trees and scraping off moss and surface soil from 1 hectare (2.5 acres) of former larch forest, rendering it as if it had been leveled by fire.

Seven years later the previously flat terrain is carved up with crevices 10-15 feet (3-5 meters) deep, creating a snowy badlands.

Gazing across a white river to the apartment blocks on a distant hill, Zimov said, "In another 30 years all of Chersky will look like this."

Link: http://hosted.ap.org/dynamic/stories/E/EU_CLIMATE_SIBERIAN_MELTDOWN?

Robert Corell, Dahl-Jensen express great concern over the increasing velocity of glacier outflow on Greenland; Gore focuses on water scarcity looming for a billion people

Robert Corell, Dahl-Jensen express great concern over the increasing velocity of glacier outflow on Greenland; Gore focuses on water scarcity looming for a billion people


COPENHAGEN (AFP) – Climate guru Al Gore warned UN climate talks Monday that the record melting of glaciers worldwide could deprive more than a billion people of access to fresh water.

"There are more than a billion people on the planet who get more than half of their drinking water -- many of them all of their drinking water -- from the seasonal melting of snow melt and glacier ice," Gore said at the release of a report he co-sponsored.

A triple threat from crumbling ice sheets, disappearing glaciers and the shrinking Arctic ice cap are feeding global warming and will fuel rising sea levels, the report found.

Adding to an avalanche of bad scientific news over the last two years, the former US vice president also cited new research showing that the Arctic ice cap may have shrunk to record-low levels last year.

"2008 had a smaller minimum, probably, than 2007," Gore said, alluding to work led by California-based researcher Wieslaw Maslowski.

"Some of the models suggest to Dr. Maslowski that there is a 75% chance that the entire polar ice cap during some summer months could be completely ice free within five to seven years," Gore said.

Scientists reported in September that the Arctic ice cover -- which helps beat back the Sun's heat-delivering rays back into space -- had reversed course compared to 2007, when it had shrunk to its smallest size since the start of accurate measurements some four decades ago.

But when measured by volume, it turns out that the 4.5 million km² (1.7 million sq miles) area in 2008 was actually smaller than the year before.

The Arctic ice cover does not affect sea levels, but is a critically important barrier to global warming.
Intact, its white surface acts as a mirror, but when the ice disappears it becomes a sponge.

"Instead of 85% of the solar energy being reflected, 85% is absorbed in the Arctic Ocean," said Gore who was awarded the Nobel Peace Prize in 2007 for his work on warning of the threat posed by climate change.

One of the report's authors, Robert Corell of the H. John Heinz III Center for Science, Economics and the Environment in Washington, pointed to another threat: the massive, accelerating loss of mass -- measured in hundreds of billions of tonnes per year -- from icesheets in Greenland and Antarctica.

Combined with the expansion of ocean water due to global warming, the continent-sized icesheets are now set to contribute to a global sea level rise of about a metre by the end of the century, double the mid-point prediction of the UN's benchmark science report in 2007.

"A one meter rise equals 100 million people who will have to move, one hundred million environmental refugees," said Corell.

"We have woken giants," said Arctic ice specialist Dorothe Dahl-Jensen at Copenhagen University of the ice sheets.

"This is really scary. This really shakes us scientists. These icesheets are enormous," she said in presenting a second report on Greenland from the Arctic Monitoring and Assessment Programme.

Greenland's ice block holds enough frozen water to lift seas seven metres, while West Antarctica could add another five metres to the global water mark.

Dahl-Jensen said the pace at which some glaciers on the west coast of Greenland were "calving," or falling into the sea, has sped up dramatically over the last decade.

"This is by far the fastest flowing ice we have ever dreamed of. This is a rate of loss that we have never seen before," she said.

Both scientists pointed out that all of these impacts had been unleashed by a less than 1.0 °C (1.8 °F) increase of global temperatures since pre-industrial times.

"Current proposals from individual countries for their own actions would lead to a temperature increase of approximately 3.8 °C (6.8 °F)", by the end of the century, Corell said.

Link:   http://news.yahoo.com/s/afp/20091214/ts_alt_afp/unclimatewarminggore_20091214190858

Greenland Ice Sheet, Glaciers 2007, II

Greenland is now a country fit for broccoli growers

The climate is changing so quickly that a land of hunters is becoming one of farmers and fearful scientists

by Isabel Hilton in Qassiarsuk, published in The Guardian online, Friday, 14 September 2007

After a summer of catastrophic flooding in Britain, it would be encouraging to see the conference season as an opportunity for British politicians to move from the highly rhetorical to the real in their climate change policies. The reaction of some Conservatives, however, to the relatively modest suggestion that airport expansion in Britain should be halted, or that those who pollute should pay, is a reminder that there are still people who suffer from the delusion that doing nothing on climate is an option, or that inaction will somehow guarantee that things stay the same. Eric Rode Frederiksen knows different.

Eric is rotund, white-haired - and clear-eyed on the subject of climate change. He was born 80 years ago in the village of Qassiarsuk in Subarctic Greenland, where an earlier Eric, the Nordic Viking Eric the Red, first established a colony in the 10th century.

One legend has it that Eric was so desperate to entice others to join him that he lied about the inhospitable nature of the vast island of rocky mountains and deep valleys. He sent word that he had found a "green land" fit for settlement. Fifteen ships did follow him, and the Viking settlement lasted nearly 500 years.

The legend does Eric a disservice. The slopes the Vikings settled were, indeed, green, and the accumulated topsoil testifies to long periods of fertility in the past. Eric and his people farmed sheep and grew potatoes, supplementing their diets with fishing and hunting. It was when the climate cooled, 400 years later, narrowing the margin of possible agriculture in southern Greenland to zero, that the Viking settlement failed and farming disappeared for 500 years. In the 20th century, Eric Rode Frederikse's father became the first Greenlander since the Vikings to give sheep farming another go. Today, 65 families are making a living as farmers in southern Greenland, the growing season is a month longer than before, and people have begun to plant little gardens. This summer, they tasted their first Greenland-grown broccoli.

As the Vikings failed in the south, in north Greenland the Inuit were thriving, equipped with effective technology and the hunting skills needed to live off the rich Arctic animal life. But two years ago, for the first time, the Greenland government had to fly dog food to the far north, emergency relief for the starving hunting dogs of the Arctic Circle. Today, Greenland's Inuit hunting communities are facing extinction.

The uneven effects of climate change are not lost on the Greenlanders. If the ice loss is a disaster for the Arctic hunters, Greenland as a whole is sitting, literally, on a gold mine. The gold is already being mined, and other resources are beckoning from the melting ice fields. Oil majors are quartering the territory, looking for fresh supplies. The aluminium giant, Alcoa, is negotiating to open three smelters in Greenland to take advantage of a bonanza in hydro-electric power. In settlements inside the Arctic Circle, where thousands of dogs still sit tethered and restless, waiting for ice that no longer comes, Greenlanders are about to be catapulted into an industrial age.

They have little choice but to adapt. In the Arctic, the mirror of life for the rest of the planet, things are now changing at a dizzying pace that far outstrips the cautious estimates of the Intergovernmental Panel on Climate Change, or even the expert assessments of the Arctic Council. For instance, the sea around Ilulissat, the biggest town in Arctic Greenland, always froze between December and the end of May. It has not frozen at all for the last three years. The IPCC predicted an ice-free Arctic by the end of the century; some scientists now predict it for 2020. Ten years ago, it was thought that the Greenland ice cap - 11,000 feet high in some places - would take centuries to melt. Now, the pace of melting of the ice cap, and the unpredictable interaction of the feedback loops such melting may trigger, makes any firm prediction hazardous. In Greenland they know human civilisation is already entering unknown territory.

Robert Corell, a US-based Arctic scientist and member of the IPCC, described what he had found three weeks ago on a visit to the ice cap. "I spent four months on the ice cap in 1968 and there was no melting at all," he told participants in the Symposium on Religion, Science and Environment in Greenland this week. "Now it's dramatic. There are thousands of moulins - holes that go down into the ice. You can hear water roaring and gurgling. Nobody knows now how quickly it will melt, but the palaeo-data tells us that at three degrees warmer than at present, the ice cap will melt. The projections for global temperature increases are now between three and four degrees."

Greenlanders have waited a long time for prosperity and, bizarrely, climate change may bring it, ending the need for the present annual subsidy from Denmark of $10,500 a year for each of Greenland's 55,000 inhabitants - equivalent to roughly half the Greenland national budget. Future economic promise is fuelling an independence movement; but for the rest of the world, Greenland's melting ice threatens catastrophe. So vast is the Greenland ice sheet that it works as a regional air conditioner. The albedo effect - the reflection of 80% of the sun's heat by the snow and ice - keeps temperatures in the region cool. But as the ice melts, the dark seas and the bare rock surface absorb heat, further accelerating melting and triggering sea level rises that will inundate, among other places, the Nile Delta, much of San Francisco and 40% of Bangladesh.

Arctic scientists are having to tear up their recent predictions and start again. "This is all unprecedented in the science," Corell explains. "Until recently we didn't believe it possible, for instance, for water to permeate a glacier all the way to the bottom. But that's what's happening. As the water pools, it opens more areas of ice to melting."

"For the last 10,000 years," Corell says, "we have been living in a remarkably stable climate that has allowed the whole of human development to take place. In all that time, through the mediaeval warming and the Little Ice Age, there was only a variation of 1C. Now we see the potential for sudden changes of between 2C and 6C. We just don't know what the world is like at those temperatures. We are climbing rapidly out of mankind's safe zone into new territory, and we have no idea if we can live in it."

isabel.hilton@guardian.co.uk

Greenland Ice Sheet, Glaciers 2007

Shockwaves from melting icecaps are triggering earthquakes, say scientists

By Daniel Howden, in Ilulissat, Greenland

http://environment.independent.co.uk/climate_change/article2941866.ece

Published: 08 September 2007, The Independent

High up inside the Arctic circle the melting of Greenland's ice sheet has accelerated so dramatically that it is triggering earthquakes for the first time.

Scientists monitoring the glaciers have revealed that movements of gigantic pieces of ice are creating shockwaves that register up to three on the Richter scale.

The speed of the arctic ice melt has accelerated to such an extent that a UN report issued earlier this year is now thought to be out of date by its own authors.

The American polar expert Robert Correll, among the key contributors to the UN International Panel on Climate Change (IPCC) report issued in February, described the acceleration as "massive".

Estimates of the likely rise in sea levels this century vary, and the IPCC published a conservative range of between 20cm-60cm. But those estimates are now heavily disputed, with many scientists insisting that new data collected since the IPCC report suggested a rise closer to two metres. Professor Correll said there was now a "consensus" that a significant acceleration in the loss of ice mass has occurred since the last report.

The revelations came at a conference in the north of Greenland, which has drawn world religious leaders, scientists and environmentalists to the Ilulissat Icefjord. Ilulissat is home to the most active glacier in Greenland and it was one of the immense icebergs that calve from it on a daily basis that is believed to have sunk the Titanic. The Arctic is acknowledged as the fastest warming place on earth.

The local Inuit population, whose lives have been drastically altered by the changing climate, were yesterday led in a silent prayer for the future of the planet by the Ecumenical Patriarch Bartholomew, the organiser of the arctic symposium and spiritual leader of the world's 250 million Orthodox Christians.

Greenland's ice cap is immense, the second largest in the world, and its break-up would be catastrophic. The packed ice is up to two miles thick and its total collapse into the ocean would raise worldside sea levels by seven metres.

At the Ilulissat Icefjord, 250km north of the Arctic Circle, the advance of the glacier into the sea is now visible to the naked eye. "It's moving toward the sea at a rate of two metres an hour," said Professor Correll. "It's exuding like toothpaste, moving towards us at 15 kilometres per year."

One day's worth of the Ilulissat ice would provide enough fresh water to supply the largest cities in the world for a whole year – and yet it amounts to only 7 per cent of Greenland's total melt.

As the glaciers thaw, pools of water are forming, feeding fractures in the ice, down which the water flows until it hits the bedrock.

"These so-called moulins are phenomenal," said Professor Correll, who said they had been remarkably scarce when he first visited the glacier in 1968. "Now they are like rivers 10 or 15 metres in diameter and there are thousands of them."

He compared the process to putting oil underneath the ice to make it move forward faster.

As the reality of the unprecedented thaw becomes apparent, the consequences are outstripping the capacity of scientific models to predict it.

Earthquakes, or glacial ice quakes, in the north-west of Greenland are among the latest ominous signs that an unprecedented step change is under way. The Finnish scientist Veli Albert Kallio is one of the region's leading ice experts and has been tracking the earthquakes.

"Glacial earthquakes in north-west Greenland did not exist until three years ago," he said.

The accelerating thaw and the earthquakes are intimately connected, according to Mr Kallio, as immense slabs of ice are sheared from the bed rock by melt water. Those blocks of ice, often more than 800m deep and 1500m long, contain immense rocks as well and move against geological faults with seismic consequences. The study of these ice quakes is still in its infancy, according to Professor Correll, but their occurrence is in itself disturbing. "It is becoming a lot more volatile," said Mr Vallio. Predictions made by the Arctic Council, a working group of regional scientists, have been hopelessly overrun by the extent of the thaw. "Five years ago we made models predicting how much ice would melt and when," said Mr Vallio. "Five years later we are already at the levels predicted for 2040, in a year's time we'll be at 2050."

This dramatic warming is being felt across the Arctic region. In Alaska, earthquakes are rocking the seabed as tectonic plates – subdued for centuries by the weight of the glaciers on top of them – are now moving against each other again.

In the north of Sweden, mean temperatures have risen above zero for the first time on record.

Professor Terry Callaghan has been working in the remote north of the country at a research station which has been taking continuous readings for the past 100 years. His recent findings tally with the accelerating pace of change elsewhere.

"Mean temperatures have remained below zero here since medieval times," said Professor Callaghan. "Now, over the past 10 years we have exceeded zero, the mark at which ice turns to water." Professor Correll said: "We are looking at a very different planet than the one we are used to."

Melting ice cap triggering earthquakes

· Estimates of sea-level rise out of date, say scientists
· Religious leaders pray for planet at Greenland glacier

• Paul Brown in Ilulissat
• The Guardian
• Saturday September 8 2007

The Greenland ice cap is melting so quickly that it is triggering earthquakes as pieces of ice several cubic kilometres in size break off.

Scientists monitoring events this summer say the acceleration could be catastrophic in terms of sea-level rise and make predictions this February by the Intergovernmental Panel on Climate Change far too low.

The glacier at Ilulissat, which supposedly spawned the iceberg that sank the Titantic, is now flowing three times faster into the sea than it was 10 years ago.

Robert Corell, chairman of the Arctic Climate Impact Assessment, said in Ilulissat yesterday: "We have seen a massive acceleration of the speed with which these glaciers are moving into the sea. The ice is moving at 2 metres an hour on a front 5km [3 miles] long and 1,500 metres deep. That means that this one glacier puts enough fresh water into the sea in one year to provide drinking water for a city the size of London for a year."

He is visiting Greenland as part of a symposium of religious, scientific, and political leaders to look at the problems of the island, which has an ice cap 3km thick containing enough water to raise worldwide sea levels by seven metres.

Yesterday Christian, Shia, Sunni, Hindu, Shinto, Buddhist and Jewish religious leaders took a boat to the tongue of the glacier for a silent prayer for the planet. They were invited by Bartholomew I, the spiritual leader of 250 million Orthodox Christians worldwide.

Dr Corell, director of the global change programme at the Heinz Centre in Washington, said the estimates of sea level rise in the IPCC report were based on data two years old. The predicted rise this century was 20-60cm (about 8-24ins) , but it would be at the upper end of this range at a minimum, he said, and some believed it could be two metres. This would be catastrophic for European coastlines.

He had flown over the Ilulissat glacier and "seen gigantic holes in it through which swirling masses of melt water were falling. I first looked at this glacier in the 1960s and there were no holes. These so-called moulins, 10 to 15 metres across, have opened up all over the place. There are hundreds of them."

This melt water was pouring through to the bottom of the glacier creating a lake 500 metres deep which was causing the glacier "to float on land. These melt-water rivers are lubricating the glacier, like applying oil to a surface and causing it to slide into the sea. It is causing a massive acceleration which could be catastrophic."

The glacier is now moving at 15km a year into the sea although in surges it moves even faster. He measured one surge at 5km in 90 minutes - an extraordinary event.

Veli Kallio, a Finnish scientist, said the quakes were triggered because ice had broken away after being fused to the rock for hundreds of years. The quakes were not vast - on a magnitude of 1 to 3 - but had never happened before in north-west Greenland and showed potential for the entire ice sheet to collapse.

Dr Corell said: "These earthquakes are not dangerous in themselves but the fact that they are happening shows that events are happening far faster than we ever anticipated."