Arctic sea ice volume heads toward record low as Northwest Passage melts free fourth year in a row

Masters rebukes disinformers: “Diminishing the importance of Arctic sea ice loss by calling attention to Antarctic sea ice gain is like telling someone to ignore the fire smoldering in their attic, and instead go appreciate the coolness of the basement, because there is no fire there. Planet Earth’s attic is on fire.”

Volume NS

Chris Mooney has a good piece in New Scientist, “Arctic ice: Less than meets the eye,” the source of the above figures.  Mooney focuses on the work of Canada’s David Barber — you can find his peer-reviewed work here:  “Where on Earth is it unusually warm? Greenland and the Arctic Ocean, which is full of rotten ice” — New study supports finding that “the amount of [multi-year] sea ice in the northern hemisphere was the lowest on record in 2009.”

Mooney also discusses the PIOMAS ice volume model developed by the University of Washington’s Polar Science Center in Seattle, which I have been featuring on CP this year.  Their analysis finds “not only has the total volume of Arctic ice continued to decline since 2007, but that the rate of loss is accelerating” [see also Arctic death spiral: Naval Postgrad School’s Maslowski “projects ice-free* fall by 2016 (+/- 3 yrs)”].

Mooney talks to Michael MacCracken of the Climate Institute who explains how an increasingly ice free Arctic will lead to “more extreme storms and heavy precipitation events in regions not used to them” like the U.S. Great Plains.

Uber-meteorologist Jeff Masters also has a great piece, “Northwest Passage opens for 4th year in a row,” which I excerpt below:

The Northwest and Northeast Passages are open
The Northwest Passage–the legendary shipping route through ice-choked Canadian waters at the top of the world–melted free of ice last week, and is now open for navigation, according to satellite mosaics available from the National Snow and Ice Data Center and The University of Illinois Cryosphere Today. This summer marks the fourth consecutive year–and fourth time in recorded history–that the fabled passage has opened for navigation. Over the past four days, warm temperatures and southerly winds over Siberia have also led to intermittent opening of the Northeast Passage, the shipping route along the north coast of Russia through the Arctic Ocean. It is now possible to completely circumnavigate the Arctic Ocean in ice-free waters, and this will probably be the case for at least a month. This year marks the third consecutive year–and the third time in recorded history–that both the Northwest Passage and Northeast Passage have melted free, according to the National Snow and Ice Data Center. The Northeast Passage opened for the first time in recorded history in 2005, and the Northwest Passage in 2007. It now appears that the opening of one or both of these northern passages is the new norm, and business interests are taking note–commercial shipping in the Arctic is on the increase, and there is increasing interest in oil drilling. The great polar explorers of past centuries would be astounded at how the Arctic has changed in the 21st century.

Figure 4. Arctic sea ice extent image for August 24, 2010, as compiled by The University of Illinois Cryosphere Today. The northern route (Western Parry Channel) through the Northwest Passage was completely clear of ice, as was the Northeast Passage. The southern route through the Northwest Passage was still partially blocked.

What caused the opening of the Northwest and Northeast Passages?
The remarkable thinning of Arctic sea ice in recent years has left behind a very thin layer of mostly 1-year old ice in the Arctic, highly vulnerable to rapid melting. As I describe in detail in wunderground’s sea ice page, this thinning was mostly due to natural wind pattern in the 1990s, much warmer than average ocean waters invading the Arctic from both the Pacific and Atlantic Oceans, very warm air temperatures, and deposition of black soot from fires used to clear agricultural land in Europe and air pollution originating in industrialized regions of the Northern Hemisphere. This year, Canada experienced its warmest winter in history, and record warm temperatures were observed during spring over the Western Canadian Arctic. Spring 2010 was the warmest in the region since 1948; some regions of the Western Canadian Arctic were more than 6°C (11°F) above average. These warm conditions helped break the ice up early in the Northwest Passage. Warm conditions continued this summer over both the Northwest and Northeast Passages, with temperatures averaging 1 – 2°C above average over the majority of the region. As observed in previous years, contributing to this year’s melt was the presence of much warmer than average ocean waters invading the Arctic from both the Pacific and Atlantic Oceans, and the deposition of black soot on the ice, which absorbs sunlight and heats up the ice. Lack of sunshine and natural wind patterns this summer helped counteract the melting, though, compared to the record melt year of 2007. Still, 2010 is on track come in 2nd or 3rd place for the lowest summertime Arctic sea ice extent on record. The past six years have had the six lowest Arctic ice extents on record, and this summer’s melting season took a huge toll on the amount of thick, multi-year old ice, according to the National Snow and Ice Data Center. Modeling results from the University of Washington Polar Science Center (Figure 5) suggest that the volume of Arctic sea ice is at a record low for this time of year. The loss of so much old, thick ice this year makes it increasing likely that Arctic sea ice will suffer a record retreat that surpasses 2007’s, sometime in the next ten years. We are still on track to see the Arctic sea ice completely disappear in summer by 2030, as predicted by a number of Arctic sea ice experts.

Figure 5. Arctic sea ice volume as computed by the PIOMAS model of the University of Washington Polar Science Center.

When was the last time the Northwest and Northeast Passages melted free 3 consecutive years?
The first recorded attempt to find and sail the Northwest Passage occurred in 1497, and ended in failure. The thick ice choking the waterways thwarted all attempts at passage for the next four centuries. While we cannot say for certain the Northwest Passage did not open between 1497 and 1900, it is highly unlikely that a string of three consecutive summers where both the Northwest and Northeast Passage opened would have escaped the notice of early mariners and whalers, who were very active in northern waters. We can be sure the Northern Passages were never open between 1900 – 2005, as we have detailed ice edge records from ships (Walsh and Chapman, 2001). A very cold period dominated northern latitudes during the 1600s, 1700s, and 1800s, known as “The Little Ice Age”, further arguing against an opening of the Northern Passages during those centuries. The Northern Passages may have been open at some period during the Medieval Warm Period, between 900 and 1300 AD. Temperatures in Europe were similar, though probably a little cooler, than present-day temperatures. However, the Medieval Warm Period warmth was not global, and it is questionable whether or not sections of the Northern Passages along the Alaskan, Canadian, and Russian shores shared in the warmth of the Medieval Warm Period. So, a better candidate for the last previous multi-year opening of the Northern Passages was the period 6,000 – 8,500 years ago, when the Earth’s orbital variations brought more sunlight to the Arctic in summer than at present. Funder and Kjaer (2007) found extensive systems of wave generated beach ridges along the North Greenland coast that suggested the Arctic Ocean was ice-free in the summer for over 1,000 years during that period. Prior to that, the next likely time the Northern Passages were open was during the last inter-glacial period, 120,000 years ago. Arctic temperatures then were 2 – 3 degrees Centigrade higher than present-day temperatures, and sea levels were 4 – 6 meters higher. It is possible we’ll know better soon. A new technique that examines organic compounds left behind in Arctic sediments by diatoms that live in sea ice give hope that a detailed record of sea ice extent extending back to the end of the Ice Age 12,000 years ago may be possible (Belt et al., 2007). The researchers are studying sediments along the Northwest Passage in hopes of being able to determine when the Passage was last open.

JR:  Just to amplify Masters on this point about the MWP not being global, we had a paper from Science last year,  Human-caused Arctic warming overtakes 2,000 years of natural cooling, “seminal” study finds.  The authors created this reconstruction of Arctic temperatures “based on more than a dozen lake sediment cores as well as glacier ice and tree ring records from the Arctic”:


Finally, Masters ends by dismantling one of the major talking points of the disinformers — and the many folks who are duped by them:

But Antarctic sea ice is at a record high!
Climate change contrarians like to diminish the importance of Arctic sea ice loss by pointing out that in recent years, Antarctic sea ice extent has hit several record highs, including in July of 2010. They fail to mention, though, the fact that ocean temperatures in the Antarctic sea ice region have warmed significantly in recent decades–and faster than the global average temperature rise! So how can sea ice increase when ocean temperatures are warming so dramatically? This topic is discussed in detail by one of my favorite bloggers, physicist John Cook over at In his words:

“There are several contributing factors. One is the drop in ozone levels over Antarctica. The hole in the ozone layer above the South Pole has caused cooling in the stratosphere (Gillet 2003). A side-effect is a strengthening of the cyclonic winds that circle the Antarctic continent (Thompson 2002). The wind pushes sea ice around, creating areas of open water known as polynyas. More polynyas leads to increased sea ice production (Turner 2009).

Another contributor is changes in ocean circulation. The Southern Ocean consists of a layer of cold water near the surface and a layer of warmer water below. Water from the warmer layer rises up to the surface, melting sea ice. However, as air temperatures warm, the amount of rain and snowfall also increases. This freshens the surface waters, leading to a surface layer less dense than the saltier, warmer water below. The layers become more stratified and mix less. Less heat is transported upwards from the deeper, warmer layer. Hence less sea ice is melted (Zhang 2007). “

This counter-intuitive result shows how complicated our climate system is. Climate change contrarians are masters at obscuring the truth by taking counter-intuitive climate events like this out of context, and twisting them into a warped but believable non-scientific narrative. Lawmakers tend to hear a lot of these narratives, since the lobbying wings of the oil and gas industry spent $175 million last year to help convince Congress not to regulate their industry. This number does not include the tens of millions more spent by the U.S. Chamber of Commerce, National Association of Manufacturers, coal industry, and other business interests intent upon stymying legislation that might cut into profits of the oil, coal, and gas industry. For comparison, the lobbying money spent by environmental groups in 2009 was approximately $22.5 million. Spending for PR efforts aimed at influencing opinion on climate change issues probably has a similar disparity. This is a major reason why you may have heard, “Hey, Antarctic sea ice is increasing, so why worry about Arctic sea ice loss?”

Diminishing the importance of Arctic sea ice loss by calling attention to Antarctic sea ice gain is like telling someone to ignore the fire smoldering in their attic, and instead go appreciate the coolness of the basement, because there is no fire there. Planet Earth’s attic is on fire. This fire is almost certain to grow much worse. When the summertime Arctic sea ice starts melting completely a few years or decades hence, the Arctic will warm rapidly, potentially leading to large releases of methane gas stored in permafrost and in undersea “methane ice” deposits. Methane is 20 – 25 times more potent than CO2 at warming the climate, meaning that the fire in Earth’s attic will inexorably spread to the rest of the globe. To deny that the fire exists, or that the fire is natural, or that the fire is too expensive to fight are all falsehoods. This fire requires our immediate and urgent attention. Volunteer efforts to fight the fire by burning less coal, oil, and gas are laudable, but insufficient. It’s like trying to fight a 3-alarm blaze with a garden hose. Every time you reduce your use of oil, gas, or coal, you make the price of those fuels cheaper, encouraging someone else to burn them. Global warming will not slow down until Big Government puts a price on oil, coal and gas–a price that starts out low but increases every year. This can be done via emissions trading, a “fee and dividend” approach, or other means. People are rightfully mistrustful of the ability of Big Government to solve problems, but we don’t have a choice. The alternative is to geoengineer our climate–an extremely risky solution. It is time to pay the big bucks and send out the fire engines, before the conflagration gets totally out of control. Consider the Great Russian Heat Wave of 2010 and the Pakistani floods of 2010 a warning. These sorts of extreme events will grow far more common in the decades to come, because of human-caused climate change.

Belt, S.T., G. Masse, S.J. Rowland, M. Poulin, C. Michel, and B. LeBlanc, “A novel chemical fossil of palaeo sea ice: IP25”, Organic Geochemistry, Volume 38, Issue 1, January 2007, Pages 16-27.

Funder, S. and K.H. Kjaer, 2007, “A sea-ice free Arctic Ocean?”, Geophys. Res. Abstr. 9 (2007), p. 07815.

Walsh, J.E and W.L.Chapman, 2001, “Twentieth-century sea ice variations from observational data”, Annals of Glaciology, 33, Number 1, January 2001 , pp. 444-448.

Zhang, J.L., 2006, “Increasing Antarctic Sea Ice under Warming Atmospheric and Oceanic Conditions”, Journal of Climate 20, Number 11, pp 2515-2529.

The Manufactured Doubt Industry and the hacked email controversy, a blog post I did in November 2009.

Jeff Masters

UPDATE:  For the sake of completeness, let me end with a chart from Wieslaw Maslowski of the Naval Postgraduate School in a presentation at the March State of the Arctic Meeting (click to enlarge):

Maslowski SMALL

*This projection is based on a combined model and data trendline focusing on ice volume.

By “ice-free,” Maslowski tells me he means more than an 80% drop from the 1979-2000 summer volume baseline of ~200,00 km^3.  Some sea ice above Greenland and Eastern Canada may survive into the 2020s (as the inset in his figure shows), but the Arctic as it has been for apparently a million years will be gone.

Related Post:


28 Responses to Arctic sea ice volume heads toward record low as Northwest Passage melts free fourth year in a row

  1. sod says:

    great article, at exactly the right time.

    JAXA sea ice extent is at 5,400,313 km2 (August 27, 2010).

    Steven Goddard on WuWt was forecasting a 5.5 mio minimum extent for this year, based on completely false information.

    “sceptics” have been talking about a “recovery” for a long time now. they base this on the data since the 2007 minimum, ignoring all other evidence.

  2. Colorado Bob says:

    Another Ice Island Breaks Off Arctic Glacier

    Sometime earlier this month, a Bermuda-sized ice island broke free from the Ward Hunt Ice Shelf along the northern coast of Canada’s Ellesmere Island.

    The breakup on this ice shelf continued a years-long pattern of retreat on the Ward Hunt Ice Shelf, and a decades-long pattern of retreat of the ice shelves along the Ellesmere coast in the high Arctic.

    NASA’s Aqua satellite detected fractures on the shelf on Aug. 18. Compared to images of the ice shelf from eight years earlier, the fractures show the dramatic change to the coast.

  3. Colorado Bob says:

    Forest Changes in Alaska Reveal Changing Climate
    Forest ecologists watch as Alaskan forests struggle with environmental changes brought on by global warming

  4. Colorado Bob says:

    For deniers, politics beats the science. Handouts beat both

    From Australia to the US, the rightwingers who claim climate change is a leftwing conspiracy will grab green subsidies

  5. Jeff Huggins says:

    A “Call For Religious Rebirth”, and Connecting Dots


    According to the news today, Beck and Palin and etc. called, in essence, for a “religious rebirth” at their big thing in Washington.

    Now – please – will the media, and the blogosphere, and all of us, start to draw out the world’s religious leaders regarding what they say is their stance regarding the responsibilities of humankind to be good stewards of Creation, to respect each other and Nature, to respect considerations of intergenerational justice, and to respect truth?

    In other words, Beck wants to hang is hat, and the Tea Party hat, on religion and religious values. Well, as it turns out (correct me if I’m wrong!), a great deal of the world’s religious and spiritual leaders have stated views that call for their flocks to respect truth, to strive to be good stewards, to respect each other and future generations, and so forth. Some, and perhaps many, of them have acknowledged the climate change problem or have at least acknowledged their deference to the scientific community on such matters.

    For example, consider the Pope’s fairly recent Encyclical Letter, titled “Caritas In Veritate”, or (roughly) “charity in truth”. It urges a respect for truth and discusses, in detail, the values of “integral human development”, responsible stewardship and respect for the Earth, intergenerational justice, and what in essence amounts to sustainability. Unless I missed something while reading it, it does not celebrate multimillionaire Fox News blabbermouths or suggest anything about Wall Street saving the world. Here’s the link:

    That’s just one example. Of course, the Dalai Lama has spoken out many times about our need to address climate change and use empathy and reason to help bring about a more sustainable, just, and humane world.

    Has Glenn Beck ever heard of St. Francis of Assisi?

    Does he understand what Confucius has said about matters pertaining to what we now call sustainability?

    I’m not an expert on the world’s religions and spiritual philosophies, but I’d bet that a very good number of them, in their official statements anyhow, call for humankind to be good stewards, to respect truth, to leave the world in excellent shape for future generations, and so forth. Of course, they aren’t speaking out enough about those things, and that’s a big shame. But, Glenn Beck has stepped into a “big one”, I think, if he thinks that tying his weird wacky wagon to religion is consistent with the way he dismisses climate change and our moral responsibility to address it.

    WHO THEN is going to call on the religious leaders, at this vital point in Earth’s history, to speak out loudly in favor of truth, responsible stewardship, justice, including intergenerational justice, and sustainability?
    The New York Times covered Beck, so now are they going to point out this discrepancy?

    I know a person doing great work on climate stuff, who sometimes posts here, who has a much better understanding than I do of the stances of the world’s religions as they relate to climate change. I hope he’ll offer a comment.

    Also, Joe/CP, perhaps you folks could do a post, at some point, regarding the stances of the world’s religions on climate change. Although they haven’t spoken out nearly enough, or done nearly enough, in my view, and I hope that will change soon, nevertheless, many of them have made official statements, I think, in support of the need to address climate change and be responsible stewards.

    I simply do not believe that our Creator, if there is one, wants us to ignore the climate mess that we ourselves have created and are imposing upon all of the world’s species as well as on future human generations!! I don’t believe it and I won’t believe it!!! At this point, organizations and people need to start showing that Beck has got it very wrong.



  6. GFW says:

    There should be a PIOMAS for Antarctic sea ice too. I bet it would show roughly constant volume (against a seasonal mean).

  7. “Disinformer” is a perfect term.

  8. Dan B says:

    I read many of the comments on Dr. Master’s blog post. The majority seemed upset by his inclusion of global warming. They wanted to talk about “real science” like tracking the hurricanes and tropical depressions. The deniers and skeptics posted much discredited, and much circulated, charts and talking points (climate is cyclical, and it will go back to normal).

    The beliefs hiding in plain sight behind their comments seems to be: If global warming is real we’ll have evil world government and the end of the free market. The leap from Global Warming to World Government / end of Freedom is the result of careful and persistent branding by the likes of CATO / Koch / Exxon Mobil and friends.

    I for one can’t fathom how the free market will survive the next decade of increasingly catastrophic climate disruption. And the lack of preparation for the looming economic crisis (worse than double-dip by a huge factor) is truly horrifying.

  9. Dan – you’re right. I read Dr. Masters’ blog fairly regularly, and whenever he talks climate there are people that just go nuts. They just want to hear his comments on hurricanes. Those they will accept as gospel. But when he talks about global climate change, he suddenly is part of the conspiracy. It’s very disheartening, but if they want to be part of a science blog, they may just have to listen to science and deal with it. We just can’t give in to their ignorance anymore.

  10. Prokaryotes says:

    “The majority seemed upset by his inclusion of global warming.”

    Because many of them work for the oil industry or people are hired to post nonsense.

  11. Prokaryotes says:

    Digg scandal: Conservative dirty tricks rig social media site
    Social media site Digg has been the victim of massive fraud perpetrated by renegade conservatives out to game the popular link-sharing website. Digg is currently investigating claims of conservative censorship and dirty tricks, as a group of users known as “Digg Patriots” have been systematically downgrading progressive stories, effectively burying a majority of liberal leaning stories.

  12. Prokaryotes says:

    For example

    Massive Censorship Of Digg Uncovered

    A group of influential conservative members of the behemoth social media site have just been caught red-handed in a widespread campaign of censorship, having multiple accounts, upvote padding, and deliberately trying to ban progressives.

    The same stuff is happening on a lot of internet platforms.

  13. Prokaryotes says:

    Question – will the arctic ocean become unstable – from methane?

    Oceanographic surveyors of the sea floor in the area of the Bermuda Triangle and the North Sea region between continental Europe and Great Britain have discovered significant quantities of methane hydrates and older eruption sites.

  14. Prokaryotes says:

    The methane—normally frozen at great pressure as gas hydrates embedded within subterranean rock—can become dislodged and transform into gaseous bubbles expanding geometrically as they explode upwards. When these bubbles reach the surface of the water they soar into the air, still expanding upwards and outwards.

    Any ships caught within the methane mega-bubble immediately lose all buoyancy and sink to the bottom of the ocean. If the bubbles are big enough and possess a high enough density they can also knock aircraft out of the sky with little or no warning.

  15. dlharman says:

    Jeff Huggins,

    Glenn Beck is a Mormon. His presiding bishop (Burton) recently stated at the opening of a new chapel that uses renewable energy:

    “We’re working very hard to find ways to conserve the precious resource, help with clean air and use those kind of resources that are environmentally responsible,” Burton said … ”

    “The takeaway message for members (of the Mormon church) is that the institution you are affiliated with is responsible,” he said. “And hopefully, the takeaway message is, maybe I need to reevaluate where I am in my responsibility to the community, responsibility to the environment and responsibility to good stewardship of this finite land and ground that the Lord has blessed us with.”

    Yes. It seems that many think that Sunday and the rest of the week are two different worlds!

  16. Ricki says:

    Perhaps methane mega bubbles are a bit off yet. But what worries me is that this political devide drives us further and further into the hole we have dug for the future.

    The disinformation campaign of the radical right continues to derail any efforts to introduce reform. Joe had a very god article on the relationship between mitigation and adaptation. They are intertwined to the degree that it is very hard to get any adaptation going, even when it painfully obvious. In my area of Sydney, my local Council and State govt have both set sea level irse benchmarks of 0.9m by 2100, 0.4m by 2050. [regardless of the fact I think this is a bit low] It is almost impossible to get planning to take this into account.

    They are talking about re-building the local waterfront of Gosford at a cost of $1billion to include housing. This area is clearly shown on THEIR OWN MAPS to be threatened by tidal inundation within 40 years. This is just profligate and reckless waste of money. And who will get caught with the property when tides are rising?

    How can we expect to get people to take seriiously the reduction needed in emissions when they won’t recognize their own benchmarks for planning purposes.

  17. MARodger says:

    The New Scientist graphic & the PIOMAS graphic are both shorn of their right-hand edge on my screen here. (Is it just my steam-powered software doing this? I don’t usually suffer such problems!) The missing bit is not obviously so & they do contain the most dramatic declines. I worry that to a casual viewer looking to believe in sea ice decline, the absence could easily suggest that the estimated 55% decline is just so much nonsense.
    Is a quick fix pissible?

    [JR: Yes. Sorry about that.]

  18. PSU Grad says:

    What really bothers me about the New Scientist sea ice volume graph is that trying to fit a linear trendline doesn’t really work. As has been pointed out over at Skeptical Science and elsewhere, a quadratic trendline seems to work best (bear with me, it’s been 100 years since I studied that stuff, so I’m at the limit of my expertise).

    If that’s the case, then this will get much worse in a relatively short period of time. Given what I’ve learned here and elsewhere about the various feedback loops, the theory and reality of climate change are converging quite “nicely”, if you can call this “nice”.

    My only remaining question would be to the “deniers”. Given existing unmistakable trends in observed data, given the science, given the stakes involved, is “denial” really the way you want to go?

    [JR: I’ll add Maslowski’s chart.]

  19. Dorothy says:

    Here’s an article from yesterday’s Vancouver Sun:
    “After thousands of years, Canada’s ‘majestic’ ice shelves disintegrating”

  20. John McCormick says:

    Hello Pete Best,

    I have read your comments on several climate blogs over the years and have watched you move steadily into the harsh reality column. I am there also.

    Your comments will likely get more pointed towards the real future ahead and not the illusory vision some have about a global renewal revival, geo-engineering, etc. Me too.

    There are not many people (two, in fact) I can talk with (and certainly not my immediate family and 22 year old step son–though my older daughter gets it entirely)about the decline of the developed world’s lifestyle and all that rich happiness requires. And, because these thoughts and conversations are considered too, too negative for the general public, environmental leaders and groups preach anything but preparing for the comet that is heading towards our over-populated planet.

    Would that absolute truth tellers could become more vocal and scare the begeesus out of us. The Kerry, legislation makes a mockery of what is actually out there banging on our door. But, when we are afraid to offend, outrage or frighten the masses, we feed the the masses soft pudding policies.

    The Dems are afraid of losing votes by telling the public of the hard reality of our changing global climate. When has US Congressional leadership ever gone to the House or Senate floor to warn America that the melt back of the Arctic ice cap is the greatest destructive impact humankind has ever delivered to our little planet; that it is not some natural freak show; that it will rebound; that we have only a decade before all summer ice (including multi-year ice) is gone and the climatological impacts will be felt across the Northern Hemisphere and even into the Asian monsoon cycle.

    Pete, it is a beautiful morning here in Northern Virginia and I am getting my garden ready for next spring. I live with hope but I am mad as hell. Keep speaking the truth.

    John McCormick

  21. Neven says:

    This blog post is old enough and has enough comments for me to mention the fact that I am still writing regular updates on sea ice extent, also containing maps and graphs of Cryosphere Today sea ice area, and weather forecasts for the coming 10 days.

    2010 will pass 2009 in a few days from now, meaning any talk of a ‘continued recovery’ is rendered moot. And if the current forecast comes about, this melting season might have an interesting tail. It could very well end up below 5 million square km, and perhaps still overtake the 2008 minimum extent.

    In the next 2 days I am releasing the End Zone-series that compare the final phase of the melt season of 2007, 2008 and 2009. The first instalment is about Air Temperature. Later today Ice Displacement. Tomorrow Ice Concentration and Sea Level Pressure.

    The comment sections on all blog posts are true treasure troves. Loads of interesting information for anyone interested in the Arctic Sea Ice.

  22. Deborah Stark says:

    Thank you for all the work you’re doing, Joe. It is appreciated more than you will ever know. And thanks very much to the respondents here from whom I have learned and continue to learn a great deal. I wish I could devote myself full-time to the study of our current situation.

    Re: PSU Grad’s question above:

    “…..My only remaining question would be to the “deniers”. Given existing unmistakable trends in observed data, given the science, given the stakes involved, is “denial” really the way you want to go?…..”

    The parties to whom you direct your question are at this late date inextricably invested in the idea that everything will ultimately turn out OK. Based on many years of observation I doubt very much this is going to change.

    That leaves the rest of us to forge ahead, to the best of our abilities, in the service of preparing for what direct observation is making increasingly obvious.

    This may sound trite and overly simplistic but I KNOW we can do it.

  23. cyclonebuster says:

    My “Underwater Suspension Tunnel” idea will put the fire out in the attic thus cooling the basement even more!

  24. JeandeBegles says:

    Joe thank you again for this very interesting post. Arctic sea ice melting is a very potent for raising people awareness) indicator of global warming and on our taca web site, we try to keep our french readers informed with the daily pictures (NSDIC) showing this melting.
    I agree that physically speaking the most important indicator is sea ice volume, but to motivate people the most trustable indicator (the one we can see for sure) is sea ice extent. My question is: since sea ice volume is decreasing every year steadily, why is sea ice extent relatively variable? If artic sea ice volume decreases while extent seems stable, then it is getting thiner every year and could vanish abruptly; in this pattern, when public opinion will get notice of the problem, it would be far too late (a bit like water lilies in the pond, doubling their extent every day, it is the day before the end that half of the pond is clearly coverred with water lilies, too late!
    Thank you again for the article and the brilliant picture of the attic and the basement.

  25. villabolo says:

    Are there any ice thickness images for July?

  26. James Prescott says:

    I’ve wondered what exactly is meant by “ice-free” summers in the Arctic. This post clarifies that at least one researcher means an 80% decline in volume. Is there general agreement on this usage, and a comparable measure from the ice extent researchers?

    Is it likely that prior to actual ice-free conditions, we’ll see the entire arctic icecap fracture into dozens, or even thousands, of chunks (sort of a giant slushee) and then refreeze (maybe in a drastically different configuration) during the winter?

  27. says:

    I think it’s already “slushee” from the pictures I’ve seen from the News Journal… the scientists called it “rotten ice”.

  28. Heater says:

    Has anybody thought about trying to predict what will happen when a Global Environmental Catastrophe and a Global Economic Catastrophe happen at the same moment in history? Because in the (admittedly non-scientific) calculus of my own observations in the world and what I’m reading from credible and very scientific sources, it seems to me that those two events are looming on roughly the same horizon. I hope I’m wrong!