Greenland Ice Sheet Melt Nearing Critical ‘Tipping Point’

JR: Last year, scientists explained that the Greenland Ice Sheet “could undergo a self-amplifying cycle of melting and warming” that is “difficult to halt.” A new study finds we may be close to a “tipping point.” Climate Central has the story.

Satellite data of Greenland reflectivity June 1-22, 2012 versus the same periods in previous Junes back to 2000. The blue colors indicate a decrease in reflectivity compared to previous Junes. Credit: NASA/

by Andrew Freedman, via Climate Central

The Greenland ice sheet is poised for another record melt this year, and is approaching a “tipping point” into a new and more dangerous melt regime in which the summer melt area covers the entire land mass, according to new findings from polar researchers.

The ice sheet is the focus of scientific research because its fate has huge implications for global sea levels, which are already rising as ice sheets melt and the ocean warms, exposing coastal locations to greater damage from storm surge-related flooding.

Greenland’s ice has been melting faster than many scientists expected just a decade ago, spurred by warming sea and land temperatures, changing weather patterns, and other factors. Until now, though, most of the focus has been on ice sheet dynamics — how quickly Greenland’s glaciers are flowing into the sea. But the new research raises a different basis for concern.

The new findings show that the reflectivity of the Greenland ice sheet, particularly the high-elevation areas where snow typically accumulates year-round, have reached a record low since records began in 2000. This indicates that the ice sheet is absorbing more energy than normal, potentially leading to another record melt year — just two years after the 2010 record melt season.

“In this condition, the ice sheet will continue to absorb more solar energy in a self-reinforcing feedback loop that amplifies the effect of warming,” wrote Ohio State polar researcher Jason Box on the blog. Greenland is the world’s largest island, and it holds 680,000 cubic miles of ice. If all of this ice were to melt — which, luckily won’t happen anytime soon — the oceans would rise by more than 20 feet.

In a new study, Box and a team of researchers describe the decline in ice sheet reflectivity and the reasons behind it, noting that if current trends continue, the area of ice that melts during the summer season is likely to expand to cover all of Greenland for the first time in the observational record, rather than just the lower elevations at the edges of the continent, as is the case today. The study has been accept for publication in the open access journal The Cryosphere.

Trend in the reflectivity of high elevation ice in Greenland, showing the record low as of June 26, 2012. Credit:

The high reflectivity of snow is what has kept Greenland so cold by redirecting incoming heat from the sun back out toward space. But with several factors combining to increase temperatures in Greenland and reduce the reflectivity of the snow and ice cover, the ice sheet is becoming less efficient at reflecting that heat energy, and as a consequence melt seasons are becoming more severe.

Freshly fallen snow reflects up to 84 percent of incoming sunlight, but during the warm season the reflectivity declines as the ice grains within the snowpack change shape and size. In addition, once snow cover melts completely it often reveals underlying ice that has been darkened by dust and other particles, whose surface absorbs more solar energy, promoting heating.

Box’s research has shown that the change in the reflectivity of the Greenland ice sheet during the 12 summers between 2000 and 2011 allowed the ice sheet to absorb an extra 172 “quintillion joules” of energy, nearly twice the amount of energy consumed in the U.S. in 2009. This extra energy has gone into raising the temperature of the snow and ice cover during summer.

“If the area of the Greenland Ice Sheet experiencing net melt expands to eclipse the accumulation zone of the ice sheet, the ice sheet will, by definition, be tipped into a state of inevitable decline,” said William Colgan, a research associate at the Cooperative Institute for Research in Environmental Sciences (CIRES) who did not participate in the new research.

In an interview shortly before leaving for a Greenland research expedition, Box said the new findings reveal that the normally snowy, windswept higher-elevation areas of Greenland are rapidly transitioning to melt during the summer in a similar manner to the lower reaches of the ice sheet.

“It appears that we’re about to cross a threshold in summer . . . you might even call it a tipping point as we go into a net energy absorption” of the higher elevations, Box said. “Then we’ll see the melt area expanding abruptly and potentially covering the entire ice sheet in summer for the first time in observations.”

Box said the shift may take another decade or so, provided that current trends continue. “We’re right on the threshold.”

Colgan said it’s difficult to make predictions based on the reflectivity record, but it would be significant if 2012 becomes another record melt year.

“The frequency with which Greenland record melt years are being established is exceptional, and certainly supports the notion that the Arctic climate is warming, and moving away from an equilibrium climate state in which extreme or record events are relatively rare,” Colgan said in an email conversation.

Andrew Freedman is a senior science writer for Climate Central. This piece was originally published at Climate Central and was reprinted with permission.

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42 Responses to Greenland Ice Sheet Melt Nearing Critical ‘Tipping Point’

  1. Here’s a naive question: Is there any way to increase the albedo of the greenland ice sheet to delay the effects described in the article? Yes, it could be considered geoengineering, but the side effects of a project like this would be less severe and unpredictable than injecting sulfates into the atmosphere (an action that I view as beyond the pale). Can anyone here knowledgeably comment about this issue?

  2. prokaryotes says:


    Sheet ice elasticity

    Although the Greenland Icecap appears, on its surface, to be hard and immobile, snow and ice are visco-elastic materials which slowly deform over time, depending on temperature and density. Despite its seeming stability, the Icecap is, in fact, in constant, slow movement- spreading outward from the center. This spreading movement, over the course of a year, causes tunnels and trenches to narrow as their walls deform and bulge, eventually leading to a collapse of the ceiling. By the summer of 1962 the ceiling of the reactor room within Camp Century had dropped and had to be lifted 5 feet (1.5 meters). During a planned reactor shutdown for maintenance in late July 1963, the Army decided to operate Camp Century as a summer-only camp and did not reactivate the PM-2A reactor. The camp resumed operations in summer 1964 using its standby diesel power plant, the portable reactor was removed that summer, and the camp was abandoned altogether in 1966.

    They removed the reactor? Really?

  3. prokaryotes says:

    Movie from 2009:

    The Greenland Ice Sheet in a Changing Climate

  4. prokaryotes says:

    The 1968 Thule Air Base B-52 crash, Thule affair or Thule accident (pronounced /ˈtuːliː/) was an accident on January 21, 1968, involving a United States Air Force (USAF) B-52 bomber. The aircraft was carrying four hydrogen bombs on a Cold War “Chrome Dome” alert mission over Baffin Bay when a cabin fire forced the crew to abandon the aircraft before they could carry out an emergency landing at Thule Air Base. Six crew members ejected safely, but one who did not have an ejection seat was killed while trying to bail out. The bomber crashed onto sea ice in North Star Bay,[Note 1] Greenland, causing the nuclear payload to rupture and disperse, which resulted in widespread radioactive contamination.[

    Eventually this contamination has now a higher chance to finds it way into the food chain. And nothing we can do about it.

  5. jyyh says:

    The tasteless joke here is of course:”Once you go black, you can’t go back.”

  6. fj says:

    Yes, there should be simple means of accelerating ice formation during the winter and slowing in the summer and one source of insight may be ice production in the New York’s Adirondacks which supplied ice as far south as the Caribbean.

    Similarly, amplifying submarine convection systems — since water starts to expand at 39 degree F — may also be a method to slow Arctic ice loss.

    The scale of this stuff is daunting but since nature provides so much for free optimizing just minor amplifying forcings in the right direction could have the potential for terrific restorative effects.

  7. fj says:

    This may not directly address an albedo solution; but, perhaps methods to accelerate insulating protective layers and methods for creating an abundance surface water temperatures much closer to freezing; obviously the idea stage of a potential research and development effort.

  8. catman306 says:

    What a really cool article for a really hot day. What was the air temperature inside that ice tunnel?

  9. Mark E says:


    How many units of energy does the ice sheet receive as sunshine?

    How many units of energy will take to melt it all?

    It’s obviously much more complicated… but I’d like to have a sense of these figures to provide a bit of context when I read “it won’t melt _too_ fast”

  10. wili says:

    So does that put us back in the realm of Hansen’s prediction of multiple meters of sea level rise, rather than just the one meter that seems to have been the consensus?

    Or does this put us beyond even Hansen’s predictions?

    Another feedback not mentioned here is that this rapid melt from albedo change in the highest parts of Greenland will be further exacerbated as those high parts melt down into ever lower ever warmer altitudes.

    Multiple feedbacks mathematically tend to turn linear systems into exponential systems and then into hyperbolic systems. We seem to be moving toward the latter.

  11. Let’s add a feedback event to this.

    With the opening of the “Northwest Passage,” how long before we see a steady amount of commercial shipping through the Arctic? And, then, when soot from marine diesel engines lands on snow on Greenland, on Baffin and Ellesmere islands, the melt accelerates more.

  12. prokaryotes says:

    Another fingerprint for Greenland ice melt ( explaining the european problem) – gravitational water mass displacement.

    The Weekend Wonk: Measuring Sea Level in Detail

  13. Jack Burton says:

    In some place in the Alps they have gone so far as to stretch huge white plastic sheets over parts of glaciers to try and slow summer melting. I would not have believed it myself had I not witnessed it with my own eyes. All these guys and a snow tractor up on a glacier trying to spread sheets of white plastic, given the scale of the glacier it seemed pure madness. Just how desperate are Alpine residents in Europe to keep some semblance of glaciers in the Alps.
    Greenland does not surprise men. Over the last few decades I have made a trip to Europe every Sept. Thus I have flown over Greenland since the 80’s at the same time of the year. May I say, in 1982 on my first trip I saw NO melt lakes on the ice sheets. Last trip in 2007 I can say they stretched as far as the eye could see from over 30K feet. Simply put, the change has been amazing and undeniable!

  14. h4x354x0r says:

    This is a very tangential question to this article, but…

    Does anyone know about research into exactly how much carbon the planet can absorb how fast? Right now, the earth is absorbing about 20 gigatons of carbon emissions (?) per year, and it appears that no matter how much carbon we release, the earth absorbs everything past a steady ~1.1% increase in atmospheric carbon PPM per year.

    But, what if there’s a limit to how much the earth can actually absorb per year, and we overshoot that? I’m just curious to know if any climate scientists have been working to get some idea of exactly how much carbon emissions the earth can actually absorb in a given amount of time.

  15. prokaryotes says:

    The 8 Minute Epoch 65 million Years with James Hansen

    We release 10.000 times faster Co2 than the natural process (carbon source = volcanoes) – which is 100 ppm in 1 million years. This depending on continental drift (how much volcanoes we get). With climate change we might get more continental drift as well, because of more geomorphological response (because of melting ice sheets and a rebound effect from the earth crust).

    The weathering process – which removes Co2 from the carbon cycle (carbon sink) took million of years to establish the Holocene climate state.

    Between the carbon source and carbon sink we have the ocean, which acts as a carbon battery. It can take several hundred years till ocean currents turn – and heat up.
    Also there is a short term feedback with more plant growth to evalated Co2 levels.

    The atmosphere on Venus has a concentration of Co2 of about 96.5%.

  16. h4x354x0r says:

    Yes, I’m basically interested in how fast the ocean “battery” can take a carbon charge. I’m certain there’s a limit there, and I’m curious what that limit is.

  17. Ray Duray says:

    Re: “With the opening of the “Northwest Passage,” how long before we see a steady amount of commercial shipping through the Arctic?”

    About 3 weeks from today.

  18. prokaryotes says:

    19.06.2012 The Arctic coastal seas absorb the greenhouse gas carbon dioxide to an ever-decreasing extent. This leads to an increase in the level in the atmosphere and an increase in the rate of warming in the Arctic. This is the conclusion from research carried out at the University of Gothenburg, Sweden.

    The results suggest that the Laptev Sea has changed from being a sink for atmospheric carbon dioxide to become a source of carbon dioxide during the late summer. This will probably be reinforced by a higher air temperature, particularly if parts of the large reservoir of stored organic matter in the Arctic tundra thaw and are carried to the sea. This will further increase the rate of temperature rise of the Earth.

    The thesis has been successfully defended.

    … things get worse again

  19. Hank Roberts says:

    I dunno. Why worry about a little ice in Greenland when the WAIS may be back in play?
    Posted as chicken-little-feed.

    Seriously, starting from the worst case makes no real difference; the best result we can imagine _still_ demands all that we can do.

    Seven billion people are going to die in the next century or so.

    Whether we do it gracefully leaving as much as possible of the world, or do it greedily, consuming as much as we might want to — is the question to focus.

    Remember Vavilov.

  20. Joan Savage says:

    The Sea of Japan is another locale in which carbon absorption has sharply declined.

    In the Guardian article, a decline in mixing of shallow and deep water was named as the contributing factor.

    (We could step that factor out to shifts in the mixing currents as warm water is more likely to stay topside, and so is lighter weight fresh-water melt from sea ice, glacier melt, and back to the lead topic, land-mass ice melt.)

  21. Omega Centauri says:

    I was pointed to some research reading realclimate. They showed that BC (Black Carbon) is a small overall effect, and that it has been decreasing recently. So presumably that effect will be small. Most of the arctic BC comes from hundreds to thousands of kilometers further south. The climate folks seem to think they can just plug in local climate parameters (precipitation and temperatures) into model albedo equations.

  22. Mulga Mumblebrain says:

    Surely, given the accelerating emissions of anthropogenic GHGs, the absolute refusal of the Right to acknowledge the problem, the incipient release of methane from submarine clathrates and permafrost, the spread of mega-fires, the thermal inertia of the oceans, the loss of Arctic summer sea ice and the huge amounts of heat absorbed by northern waters, etc, the total melting of all global ice-sheets is already more or less certain, and it is just a question of the time involved. And, seeing as we have consistently been surprised by the rapidity of events, that are occurring far more quickly than even in the most pessimistic prognostications, why is it not possible that this disaster will occur in the lifetimes of some of those already extant?

  23. Omega Centauri says:

    The simple linear models, don’t anticipate carbon reservoirs filling up (as in can take absolutely no more), but simply assume each reservoir holds a volume which in equilibrium with the atmosphere is proportionate to the atmospheric concentration. This leads to the impulse response (what happens to concentration given an unit of instantaneous release) that is a Prony series (the sum of decaying exponentials with different time constants). A significant weighting is for terms with only a couple of years (I think this is equilibration of atmosphere and surface waters), but there are some terms whose decay constant is thousands of years.
    Of course this is too simple, as ecosystem response will change these reservoirs.

  24. Rabid Doomsayer says:

    It will take a long time for the ice to melt.

    The ice does not have to melt in situ it can flow into the ocean as ice. What does melt will lubricate the unmelted ice which will speed up its journey.

  25. prokaryotes says:

    Gracefully? How is this possible? I imagine nuclear war worldwide fallout and a lot of inhabitable zones.

    At least we do not have to worry about overpopulation by the end of this century.

  26. prokaryotes says:

    That should read:

    I imagine nuclear war, worldwide fallout and a lot of uninhabitable zones, mainly due to lack of water/food supply and heat bulb temperature.

  27. Solar Jim says:

    According to my understanding of J. Hansen et al. recent energy balance analysis of the planet, the equivalent of approximately five times worldwide electric generating capacity is going toward cryosphere meltdown due to present climate (radiative) forcing.

    All trend lines appear upward, as if the response on an exponential curve were changing from the horizontal slope toward the vertical. Thus the term “threshold,” or “edge of the cliff.”

    National and international security implications are . . . difficult to contemplate.

  28. Mulga Mumblebrain says:

    The tattered remnants of humanity will become ‘stalkers’, and the whole planet ‘The Zone’.

  29. Mulga Mumblebrain says:

    ‘National security’ is bulldust. The only people and things whose security is protected by the vast military, incarceration, repressive laws and surveillance mechanisms are the rich and their property. The rest of humanity, if the elite’s plans are implemented, can, and will, go to the Devil.

  30. I am not a ‘doomsayer’, but do think we are fast approaching a period of significant change – and not just in terms of the environment.
    A few days ago, in a new blog post linked to my book Alpha to Omega, I also used the phrase ‘tipping point’. I think if you look at a range of issues, you cannot but come to the conclusion that big changes are imminent.
    One reviewer of my book concluded with the words: ‘Ask yourself, could this actually happen? The answer is yes.’

  31. Tom L says:

    Them hungree furiners is gonna threaten our freedumb.

  32. prokaryotes says:

    I think that anyone who believes into protection from climate change chaos, is illusionary. In the best cases you might have a few isolated “lifeboats” which will fail miserably after a few years or decades at best.

    Even if a small community manages to survive somehow with self sustaining technologies. How livable will be earth for the next 100.000 years to come? There is a lingering psychological toll when civilization collapses – which likely will drive most people crazy.

  33. Tom L says:

    I see the world as a pressure cooker. The heat is on and turning itself up while everything inside boils and churns until the regulator on top blows off. And then…

  34. Bleekerstreet says:

    Your observations have greater weight in the public eye than the observations of “those scientists.” One of the problems we face is that the image of scientific inquiry has been poisoned by the right. We need more observers, like yourself, to speak out. Thank you J.B.

  35. Doug Bostrom says:

    Did you notice that the article is about observational data, not models?

  36. Mulga Mumblebrain says:

    Quite a number are crazy already.

  37. Mulga Mumblebrain says:

    Forgive my pessimism (I see it as realism), but the tipping-points were clearly long ago, the worst, I’d say, the loss of Arctic sea ice, and the huge amounts of heat stored in the oceans. The fact seems to be that, if you remove the ‘global dimming’ effect of pollution, that we are already at two degrees Celsius, and that is plainly too far. The ‘points of no return’ are the omnicidal moral insanity of the Right, and the release of methane in the north. There are probably others. I find the refusal to acknowledge this reality rather understandable, but unhelpful, if you will forgive me saying so. Of course I well understand the spiritual and existential crisis such understanding causes.

  38. Tree Thunderchild says:

    I had gravel on my property in Northern Minnesota, and asked the university there for more information. Of the information I got, I was told that the 2 mile thick glacier that covered the property, melted, in 7 years.
    I think the earth can change even faster.
    Our predictions are often based on experiences of which our kind has limited experience and use what math we have to guess ahead what is going to happen, and are getting better at it.
    In my models decades ago, I included things like the simple physics involved in global warming, of ocean surface temperatures rising, which increases the rate of evaporation which increases cloud cover which increases the planets reflectivity.
    Life having existed hundreds of millions of years of volcanism, fluctuations in solar cycles, solar flairs, meteor impacts, is evident that physics are at work to KEEP the temperatures on this planet within life sustaining range, for that long.
    If I use the climate records and Co2 concentrations over the last 65myr. All I need do is go back to around 43myr ago to see where the planet was the last time, our Co2 was at this ppmv.
    Another influence I suspect is at play with the Greenland ice sheet, is more than just particulate matter on the surface from human based air pollution, but “chemical” based. That can mix with water, to raise its melting point even by one degree, then during summer melt, go below the surface where temps maintain at melting point, and this mix of water and chemicals, melt down to the bottom, lubricating the ice.
    Just speculation, being human I reserve the right to be wrong.

  39. Tree Thunderchild says:

    What was the earth atmosphere Co2 ppmv, when there was no summer ice in Greenland or Antarctica?
    From what I can see (feel free to correct me if wrong!) We already crossed that point.

  40. Duncan Forbes says:

    Today is the 4th of July, and I am about to go watch a parade. Many of my fellow Americans are in denial (or a related state of intentional ignorance) about climate change. I believe that only a relatively abrupt catastrophic event — say, the very rapid collapse of the southern sixth of the Greenland ice sheet — will produce action of the level required. People simply aren’t hard-wired to react to “glacially-slow” change.
    On the subject of non-linear and/or step function-type change, few discuss the vast pools of methane that could be liberated quickly. The Siberian and Canadian permafrost contains a huge amount of locked-up methane. The gas will no doubt be released fairly quickly over the next few decades. The deep ocean methane ices contain even more. Those ices exists in a complex phase regime due to pressure and temperature. I have not been able to find out just how delicate that balance is. I guess we’ll find out when the Arctic ocean starts to effervesce like champagne.

  41. Fascinating research and interesting results. I’ll follow it now I’ve found it. But curiously, Box doesn’t mention CO2 as a factor in the ice sheet’s accelerated melting.

    Richard Treadgold
    Climate Conversation Group