Data Shows Thinning Arctic Sea Ice

The latest satellite observations of sea ice in the Arctic shows the ice cover appears to be shrinking: the ice cap is getting smaller, and thinner as well. The ice has been receding more in the summers and not growing back to its previous size and thickness during the winters. Scientists say the ice is profoundly important, as ice is the defining characteristic for the eco-system of the Arctic region. But it is also important for the entire planet, as far as constraining the Earth’s heat budget, and affecting ocean flows and planetary weather.

Arctic sea ice works like an air conditioner for the global climate system. Ice naturally cools air and water masses, plays a key role in ocean circulation, and reflects solar radiation back into space. In recent years, Arctic sea ice has been declining at a surprising rate. As ice melts it is replaced with darker sea water that absorbs more sunlight and heats up the ocean and the planet overall.

According to researchers from the National Snow and Ice Data Center in Boulder, Colo., the maximum sea ice extent for 2008-09, reached on Feb. 28, was 5.85 million square miles (15,151,430 square kilometers). That is 278,000 square miles (720,016 square kilometers) less than the average extent for 1979 to 2000. This is the fifth lowest maximum ice extent on record. The six lowest maximum events since satellite monitoring began in 1979 have all occurred in the past six years (2004-2009).

Maps show the relative age of Arctic sea ice at the end of February 2009 and over time. Thin, first-year ice is the predominant type covering the Arctic Ocean this winter. Credit: From NSIDC, courtesy Chuck Fowler and Jim Maslanik, University of Colorado
Maps show the relative age of Arctic sea ice at the end of February 2009 and over time. Thin, first-year ice is the predominant type covering the Arctic Ocean this winter. Credit: From NSIDC, courtesy Chuck Fowler and Jim Maslanik, University of Colorado

Until recently, the majority of Arctic sea ice was multi-year ice, which means it survived at least one summer and often several winters. This multi-year ice is thicker and can survive longer than the seasonal ice that melts and re-freezes every year. But things have changed dramatically. According to the scientists, the thin, seasonal ice now makes up about 70 percent of the Arctic sea ice in wintertime, up from 40 to 50 percent in the 1980s and 1990s. Thicker ice, which survives two or more years, now comprises just under 10 percent of wintertime ice cover, down from 30 to 40 percent.

“9.8 percent of the ice is greater than 2 years old,” said Walt Meier, research scientist with NSIDC, at a teleconference with reporters today. “So, it’s about a third of what it used to be in terms of really old thick ice.”

Meier said the thickest and oldest ice has been on a big decline the past couple of years. “Right now, this is the lowest we’ve had,” he said. “Last year, multi-year ice made up 14 percent of the Arctic ice cap. In 2007, it was about the 25% range. That is a pretty sharp decrease. We did see some recovery in 1-2 year old ice, which is up from a low of 5 %. In theory that ice could survive, if it doesn’t get exported out of the Arctic.”

The solid blue line indicates daily sea ice extent from late 2008 to early 2009. The dashed green line indicates sea ice extent in winter 2006-07 (leading up to the record-low minimum in summer 2007). The solid gray line indicates average extent from 1979 to 2000. This year’s maximum winter ice extent occurred on February 28, 2009. Credit: National Snow and Ice Data Center
The solid blue line indicates daily sea ice extent from late 2008 to early 2009. The dashed green line indicates sea ice extent in winter 2006-07 (leading up to the record-low minimum in summer 2007). The solid gray line indicates average extent from 1979 to 2000. This year’s maximum winter ice extent occurred on February 28, 2009. Credit: National Snow and Ice Data Center

Winds and ocean flows also “flushes” ice out of the Arctic region, Meier said.

Data from NASA’s Ice, Cloud, and land Elevation Satellite (ICESat) has now produced first map of sea ice thickness over the entire Arctic basin.

Ron Kwok from JPL who works with ICEsat said, “This is the first time we’ve had Arctic-wide ice thicknesses at the scale. During the 70’s and 80’s the average ice thickness was about 1.5-2 meters thicker than what we’re seeing at the current time.” Those measurements were taken using submarines and drill holes. Using ICEsat allows for the entire ice cap to be measured from space. ICEsat has been taking data for five years, and only the first two years of data (2005 and 2006) has been fully processed, but preliminary results show the decline is continuing.

During the teleconference, a journalist from northern Canada said their region has been experiencing colder winters the past couple of years, and asked if that was a good sign. “The ice is still in a precarious position,” said Meier, “and we can’t focus on short term trends of one or two years. Long terms trends show a warmer Arctic and thinner sea ice. It will take several cold years in a row to get back to where it was and to get the thick multi-year ice that can survive longer. This is not something that can be turned around in a couple of cool summers and colder winters.”

When asked if they could determine the ice depletion has come from natural or man-made causes, Meier said, “Sea ice certainly varies a lot over time, and we have fairly good records on how it has varied back to the early 1900’s, and we are confident it is much lower than it ever has been in the past half century. It’s clear the sea ice changes we are seeing go hand-in-hand with the warming planet, and the sea ice changes are entirely consistent with that. There isn’t another mechanism that could cause the long term changes we’ve seen.”

Sources: NASA, news conference

27 Replies to “Data Shows Thinning Arctic Sea Ice”

  1. Some of it is natural, but I think some of it is manmade. SUVs, 4x4s, gas guzzlers, polluting industries, economic/population growth, environmental destruction and deforestation… it’s logical it can’t go on forever on a finite planet without effects. Look what we did to the ozone layer with CFCs….

  2. so what’s wrong with economic growth?
    population growth? talk to the muslims and chinese

  3. I blame all those silly women who pick up their kids from school in flipping tanks & range rovers – honestly you would think their driving through a war zone.

    Women and their 4 x 4’s have brought a premature end to all live on Earth!

  4. If you want to talk about carbon, lets talk about concrete and the power sources used to make large cities habitable. The simple act of mass producing goods has a larger footprint than cars.
    If you want to talk about deforestation and overfishing, lets share some words about all those Mc Meals that everyone thinks are made from thin air at the restaurant.

    Trucks and SUV’s are the least of our worries. Yet everyone seems to sink their teeth into that first as if getting rid of the soccer mom that cut them off this afternoon would somehow improve the world.

  5. Max,

    Passing the buck onto the next most obvious offender doesn’t solve the problem either.

  6. Quote: “There isn’t another mechanism that could cause the long term changes we’ve seen.”

    Uhmmm…This guy works for NASA. I want to know if he’s ever heard of the Sun?

    This report also seems to run contrary to a report (BY NASA) in 2007 that stated the current trend in Arctic ice reduction may be due to factors involving the wind (

    Moreover, rather than jump to conclusions about soccer moms, SUVs, fast food, population problems etc. etc. etc. I think it would behoove us to look at all the data rather than jumping on the bandwagon and believing what we are told.

  7. Out of six responses, only one poster believes this is just another made-up story about ‘global warming’? By what I’ve read here recently, it seems there a lot of people out there who deny there is any problem at all! Regardless of the culprit, I would hope most rational people realize we’ve got a problem here and need to seriously look at possible solutions. The newer data is more alarming, showing a more rapid warming than that predicted a few years back. I suppose global warming deniers will always be there but the more affluent will just move to higher ground and get super looking tans.

  8. But you made my point for me. I wasn’t claiming to be a non-believer. Rather, I was saying to look at all the data before jumping on the bandwagon.

    The story I referenced was froma few years ago and was NOT doom and gloom. As a matter of fact, it was from NASA research and showed there could be other explanations than global warming to account for what we are seeing.

    The fact is, the Arctic Sea ice IS shrinking…BUT…we don’t know why. The fact also is that the ANTARCTIC ice is ABOVE average. If you don’t believe me, look at the data.

    My entire point was to LOOK at the data and analyze it. Don’t just decide that it automatically is global warming. There are numerous other explanations and we need to determine what is going on.

    I am neither for or against global warming, climate change, or whatever other political term you want to put on it. I am for science and determining what is REALLY going on.

  9. Oh we have global warming- And I too am glad that I live on high ground. Of course this will not do me or my great grandchildren much good if the Earth turns into a planet that resembles Venus.

  10. Riiiight so has anyone on the damn planet ever heard of an “Interglacial Period”? For the love of Pete, we’re just Lucky we’re not rumbling head first into an Ice Age because I don’t think the Windy City would be a good vacation spot under a MILE of Ice. YES the Planet is Warming Up. It’s happened with the predictability of a Nursery rhyme for millenia and will continue to do so very probably for a loooong time.

    We are almost CERTAIN to kill ourselves through pollution and resource depletion well before we ever need to fear teh Oceans rising another 20 feet or so (Incidentally the oceans have already Risen more than 100 feet since the ice sheets from the last Ice Age receded).

    Further more, since I’m pontificating, if you actually Think About It, Global Warming is a HUGE BOON to plants all over the world, Higher quantities of CO2 in the air, Longer Growing Seasons, less harsh Winters and less Water Locked up in Ice at the Poles. The World has the potential to be a verdant explosion of floral magnificence, so long as we manage not to turn it into a massive ball of molten glass and toxic chemicals first.

  11. If the polar icecaps melt too fast, the Oceanic Global Coveyor Belt will stop- the heavier salt water of the Gulf Stream will stop sinking off NE North America. It is possible to start an ice age, this will be a boon to places like California and North Africa with more rain, but the Nordic Countries will be greatly affected first. Of course, this will be a slow process,measured in each generation. In a way, this will be a great disaster in its own right!!!

  12. “Riiiight so has anyone on the damn planet ever heard of an “Interglacial Period”? For the love of Pete, we’re just Lucky we’re not rumbling head first into an Ice Age”

    “Global Warming is a HUGE BOON to plants all over the world”

    Hmm, and perhaps you’ve heard of a “Climate Zone?” You know, the fact that the vast majority of the planet is not going to benefit from increasing temperatures, because it’s either desert already (say hello to 140 degree days!) or temperate (get your casino permits ready, time for some fun in the sand!)

    Gee, pointing out the obvious and posting random links to Wikipedia * can * be fun. Thanks.

  13. First, the same source (National Snow and Ice Data Center) used in this article also says Antarctic Sea Ice is growing:
    Of course they contribute the growing sea ice to Global warming too.
    There is no disclaimer that the climate doesn’t operate on a linear trend. It can also be argued that 20 years of data linear regressed doesn’t define a “climate”.
    Why is it that people who can understand things happening on a cosmic time scale turn a blind eye to climate on a geologic time scale? Any astronomy buffs ever heard of Milancovitch cycles? Why is CO2 concentration in our atmosphere so low when compared to a major percentage of earth’s history?
    Why has melting increased since the 80’s? Looks to me like emissions standards and a reduction in 8 cyl. Vehicles on the road are the problem. Or is it the ozone layer?
    If all of you who accept only half the facts about earth’s climate and emphatically deny the other half will excuse me, I have to go turn on all the lights in my house and let my car idle in my driveway for a few hours.

  14. Our entire modern civilization is based on power from fossil fuels. Mechanized agriculture, transportation of food, earth moving for construction, international commerce, are all dependent on petroleum. Generating the equivalent amount of energy with ethanol would require 100% deforestation of the planet to grow enough grain. Electric vehicles are simply too inefficient to use for most of the heavy applications that support our civilization.

    Freeing ourselves from fossil fuels will require radical re-structuring of our landscape and society to use electric rail for most heavy transportation. Cities will have to be smaller and denser, more people will have to return to subsitance farming, and the population will have to go down.

  15. Inconclusive data.

    Those charts are like looking at one piece of a million piece puzzle. You will never guess the real picture.


  16. Silver Thread Says
    I’ve studied the Koppen Climate Classification as a hobby-as it was orginally posted, there had to be modifications, take CS climate or Mediterranean climate-dry summers,mild moist winters. In the US pacific northwest like Seattle,Wash and Portland,Ore., the rainfall regime is exactly like that of the CS climate, so dry in summer irrigation is necessary, yet, the area has hugh coniferous trees, as Koppen posted it, these areas were considered CS climates. It was later modified to say less than 3 months must be <50F or 10C. Global warming will cause areas like N Africa and most of the middle east from 35-40N to lose their winter rains and become arid, in N.America, California will become semi-arid. The strange part is, the tropical wet-dry AS,AW climates will start ruling the Gulf coast states and areas like San Diego will have their only rains in the summer. The climatic zones generally will shift 10 degrees further poleward in the Northern Hemisphere, some areas will benefit like SE Canada and Siberia but other areas will suffer arid conditions.
    There will be more arid conditions in areas now heavily populated and will be a disaster, but for places like the southern Sahara desert, there will be an increased areas of tropical wet-dry climates. The migrations of hundreds of millions of people can/will cause great wars. On the other hand, if the world goes back into an ice age, areas like California or N. Africa will have the climates more liken to Seattle Washington or central Europe rainfall regime, but much areas will be lost by the ice covering the northern areas. The biggest sufferers will be much of Europe as hundreds of millions live above 50 degrees north. In North America, there are only 2 moderate size cities above 50 degrees North. The entire southern hemisphere will not have the great changes as oceans covers a far larger area than the N.hemisphere. In short, to have an ice age or much warmer temperatures will mean a great migration and wars will be staged for

  17. I made a mistake about the southern Sahara wording, in the event of global warming, the the southern Sahara desert will have an increased areas of tropical wet-dry seasons, or AW or AM, a few areas further south will have a AF or tropical rain forest climate.
    In areas like India that is the text book example of the monsoon climate, their climate may develope more into a AF climate
    or all year rains and the southern Arabia
    landmass will have more tropical wet-dry seasons. I was able to catch in the weather web sites last July 08 a powerful tropical storm that entered the Gulf of Oman, the first in over 60 years with heavy rains and winds to 100mph(165KMH), the storm died out by the time it got to the Strait of Hormuz. Very few knew about this as this was a local event and a few were killed. It was interesting as I followed the real-time hour to hour path
    of this storm in the most unusual place!!!!

  18. Tyler Durden Says:
    Duhhhhhh, I meant the message was for you, Lol, geeez, I sure messed that up, but the climatic charts and my response was for you.
    To all, my previous 2 posts had to do with Tyler Durden climatic zone charts
    I made a boo-boo,,lol

  19. I don’t know about charts and statistics and how to interpret them, and all the politics. I read many climate change/warming denials, and many claims that it’s true.

    Here is my own observation, regardless of statistics and charts:
    1) aged 17, I took some spectacular photos of glaciers in the Austrian Alps. 40 years later all those glaciers have gone without a trace.
    2) 40 years ago, the greening of the trees in central Europe happened at least 14 to 16 days later than now. I am certain about this – it used to be a little over a week after my birthday – now, it’s about a week before my birthday.
    3) there used to be (Russian) ice breaker tourist trips to the North Pole, during the Summer (daytime at the pole). One of the highlights was: everybody get out of the ship, stand around the pole, and have a group photograph taken. This be became unsafe around the turn of the century – the ice became too thin. Now, those trips are on again. The attraction now is: swimming at the North Pole.
    4) a glimmer of some hope: the Winter which is coming to an end now (in Europe) has been one of the longest winter sport seasons most people I know who are into skiing remember.

  20. This Helped heaps for a skool assignment. thanks. btw Michael thomas is a legend!

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