Tech | June 05, 2010 | 23 comments

Arctic Ice At Low Point Compared To Recent Geologic History

source: http://www.spacedaily.com/reports/Arctic_Ice_At_Low_Point_Compared_To_Recent_Geologic_Histor...

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JanforGore
Less ice covers the Arctic today than at any time in recent geologic history. That's the conclusion of an international group of researchers, who have compiled the first comprehensive history of Arctic ice.

For decades, scientists have strived to collect sediment cores from the difficult-to-access Arctic Ocean floor, to discover what the Arctic was like in the past. Their most recent goal: to bring a long-term perspective to the ice loss we see today.

Now, in an upcoming issue of Quarternary Science Reviews, a team led by Ohio State University has re-examined the data from past and ongoing studies - nearly 300 in all - and combined them to form a big-picture view of the pole's climate history stretching back millions of years.

"The ice loss that we see today - the ice loss that started in the early 20th Century and sped up during the last 30 years - appears to be unmatched over at least the last few thousand years," said Leonid Polyak, a research scientist at Byrd Polar Research Center at Ohio State University. Polyak is lead author of the paper and a preceding report that he and his coauthors prepared for the U.S. Climate Change Science Program.

Satellites can provide detailed measures of how much ice is covering the pole right now, but sediment cores are like fossils of the ocean's history, he explained.

"Sediment cores are essentially a record of sediments that settled at the sea floor, layer by layer, and they record the conditions of the ocean system during the time they settled. When we look carefully at various chemical and biological components of the sediment, and how the sediment is distributed - then, with certain skills and luck, we can reconstruct the conditions at the time the sediment was deposited."

For example, scientists can search for a biochemical marker that is tied to certain species of algae that live only in ice. If that marker is present in the sediment, then that location was likely covered in ice at the time. Scientists call such markers "proxies" for the thing they actually want to measure - in this case, the geographic extent of the ice in the past.

While knowing the loss of surface area of the ice is important, Polyak says that this work can't yet reveal an even more important fact: how the total volume of ice - thickness as well as surface area - has changed over time.

"Underneath the surface, the ice can be thick or thin. The newest satellite techniques and field observations allow us to see that the volume of ice is shrinking much faster than its area today. The picture is very troubling. We are losing ice very fast," he said.

"Maybe sometime down the road we'll develop proxies for the ice thickness. Right now, just looking at ice extent is very difficult."

To review and combine the data from hundreds of studies, he and his cohorts had to combine information on many different proxies as well as modern observations. They searched for patterns in the proxy data that fit together like pieces of a puzzle.

Their conclusion: the current extent of Arctic ice is at its lowest point for at least the last few thousand years.

As scientists pull more sediment cores from the Arctic, Polyak and his collaborators want to understand more details of the past ice extent and to push this knowledge further back in time.

During the summer of 2011, they hope to draw cores from beneath the Chukchi Sea, just north of the Bering Strait between Alaska and Siberia. The currents emanating from the northern Pacific Ocean bring heat that may play an important role in melting the ice across the Arctic, so Polyak expects that the history of this location will prove very important.

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23 comments // Arctic Ice At Low Point Compared To Recent Geologic History

  • diode
  • tommic
    • 0
      tommic  

    • Arguing and debating people who do not believe whats happening to the climate, atmosphere and enviornment is a waste of time and energy. Only people predisposed to an open mind and open evaluation of evidence can be swayed if they are doubting the effects of man made pollutents and gases that are effecting the planet. Concerned scientist are overwhelmingly in agreement that the industrial age and burning of fossil fuels is responsible for most of temprature change and ice loss. After the Arctic goes so will the Greenland ice sheets and then there will be no turning back what will come. it will not be pretty, tens of millions of coastal refugees, economic losses in the trillions in land lost to rising seas. So Ice Kat go on playing your game of disbelief, people like you are the problem standing in the way of solution. Too Bad.

      thomas mcmahon
      millis ma

    • 2 years ago
  • IceKat
  • tommic
  • IceKat
  • JanforGore
    • +1
      JanforGore  
    • IceKat:

      You will never get it. We are not talking about 1922, 1833, etc. we are now living in 2010, and all of the data shows extensive rapacious warming NOW, with the effects of that warming making itself known NOW. I could sit here as well posting about year after year of temperature anomalies, but it doesn't disprove anything regarding the data NOW, and the forcings contributing to the timeframe this is all happening in NOW. So please, do us all a favor and spare yourself anymore embarassment with your lame attempts to discount REAL scientists.

    • 2 years ago
  • IceKat
  • JanforGore
  • IceKat
  • JanforGore
    • -1
      JanforGore  
    • IceKat:

      It wasn't an attack, it was the truth backed by scientific facts. Something that fraud wouldn't know if it bit him on his arrogant elitist bum. What you used here is based on the same illustration Monckton used sans the faux royalty symbol in the corner. S O S. And of course he wrote a response. A long diatribe that says absolutely nothing. But at least he has something to do now to pass the time by attacking someone other than Al Gore. Pathetic.

    • 2 years ago
  • JanforGore
    • 0
      JanforGore  
    • Image

    • http://www.guardian.co.uk/environment/2010/jun/02/2010-could-be-warmest-year-eve...

      2010 on track to be warmest year ever

      Excerpt:

      "Figures from US scientists show Arctic sea ice is at a record low, while land temperatures are likely to hit new highs

      • Nasa scientist James Hansen condemns 'politicised' media
      US figures show that arctic sea ice is now at the lowest extent ever recorded for the time of year. Photograph: John McConnico/AP

      New data from some of the world's leading climate researchers and institutions suggest that 2010 is shaping up to be one of the warmest years ever recorded.

      Scientists at the US National Snow and Ice Centre Data Centre (NSIDC) report today that Arctic sea ice – frozen seawater that floats on the ocean surface – is now at its lowest physical extent ever recorded for the time of year, suggesting that it is on course to break the previous record low set in 2007.

      Satellite monitoring by the NSIDC in Boulder, Colorado, shows that the melting of sea ice has been unusually fast this year, with as much as 40,000 sq km now disappearing daily.

      The melt season started almost a month later than normal at the end of March and is not expected to end until September.

      Meanwhile, research from the polar science centre at the University of Washington suggests that the volume of sea ice in March 2010 was 20,300 cubic km, 38% below the 1979 level when records began.

      Global surface temperatures may also be at a record high, according to leading climate scientist James Hansen and colleagues at the National Aeronautic Space Administration (Nasa).

      In a paper which is yet to be peer-reviewed but has been submitted to the journal Reviews of Geophysics, they suggest that the Earth has been 0.65C warmer over the past 12 months than during the 1951 to 1980 mean, and that the global temperature for 2010 will exceed the 2005 record.

      Hansen, credited with being one of the first scientists to study climate change, dismisses sceptics' claims that global warming "stopped" in 1998.

      "Record high global temperature during the period with instrumental data was reached in 2010," he writes.

      "It is likely that the 2010 global surface temperature ... will be a record.

      "Global warming on decadal timescales is continuing without let-up ... we conclude that there has been no reduction in the global warming trend of 0.15-0.2C/decade that began in the late 1970s."

      The Nasa research backs up findings by the US National Oceanic and Atmospheric Association (NOAA), the US national climate monitoring service that measures global temperatures by satellite. This has recorded the hottest ever first four months of a year.

      As a result of high sea surface temperatures, the Atlantic hurricane season – which officially started this week – is expected to be one of the most intense in years.

      Last week NOAA predicted 14 to 23 named storms, including eight to 14 hurricanes – three to seven of which were likely to be "major", with winds of at least 111mph.

      This is compared to an average six-month season of 11 named storms, six of which become hurricanes, two of them major."

    • 2 years ago
  • JanforGore
    • +1
      JanforGore  
    • Image

    • http://data.giss.nasa.gov/gistemp/
      NASA giss temperature updates as of 6/2/10 show continued warming. April 2010 was quite warm in relation to the 1951-1980 mean ( which are the dates used in this graph.)

      Specifically looking at the Arctic region and the rapacious pace at which the ice is now melting, natural variances alone cannot account for it.

    • 2 years ago
  • IceKat
  • JanforGore
    • -1
      JanforGore  
    • IceKat:

      Stepping out for second here:

      "Notice how GISTEMP always runs hotter than the others. There are reasons for that, usually selective measurements and badly placed sensors."

      LOL, of course, because it doesn't conform to what you want others to see. And just to point out to you, it is disingenuous to compare one temperature from "central england" in 1833 to a global trend now. You really are grasping at straws, and seemingly very attached to me here. It is actually getting kind of creepy.

    • 2 years ago
  • IceKat
  • JanforGore
    • -1
      JanforGore  
    • IceKat:

      I didn't say I didn't "like it" , I stated it was disingenuous to compare it to a "global" trend happening now. And actually, by your logic it then follows that any information I quoted is just as signifcant and just because you don't like it doesn't make it wrong or inaccurate. See how that works? And of course by all means keep latching onto me if you must. I'm sure you are paid well for your time.

    • 2 years ago
  • IceKat
  • JanforGore
    • 0
      JanforGore  
    • IceKat:

      What will I say? I will thank the REAL scientists and those who warned us about this and those who actually heeded those warnings in decreasing GHG emissions enough to actually see some progress should that hopefully happen. But since scientific warnings state that Arctic ice could reach a tipping point by MID CENTURY if that does not happen we will still have to monitor the situation because even with a marked decrease in CO2, the CO2 already up there since the Industrial Revolution is already contributing to the melting. That is why decreasing our emissions NOW matters, which BTW includes sequestering CO2 in soil and providing carbon sinks as well as DEcreasing our reliance on fossil fuels. And there is nothing wrong with my information which was given by actual climate scientists who actually know of what they speak. The only problem is your retiscence to open up a science book. And as far as your funding, it matters not where it comes from. They're all scumbags and so are those who shill for them.

    • 2 years ago
  • JanforGore
  • JanforGore
    • +1
      JanforGore  

    • We spew out CO2 like BP spews out oil. Both practices need to end. This shouldn't be about politics. Politics is what is blinding people to the true urgency of the climate crisis.

    • 2 years ago
  • IceKat
  • JanforGore
    • 0
      JanforGore  
    • IceKat:

      I am no longer debating this SCIENTIFIC FACT with you or any other of your BS throwers here any longer. Worldwide climate change is now happening, and it is people like you who are tying to make others believe it is not happening or not important. You therefore to me are nothing more than an accomplice in the cataclysm that we will face in the future, because you didn't give a damn in the present. For me to continue to sit here sparring with the likes of you ONCE AGAIN would be as one sparring with someone over whether gravity holds us down. Don't even bother to address me here again with your assinine explanations of why you don't believe CO2 is a heat trapping gas. That alone shows you for the idiot you are and I then have no other reason to discuss this with you any further.

    • 2 years ago
  • jeffissleeping
    • +2
      jeffissleeping  

    • this article will never be read by Sean Hannity...because he's too busy huffing paint to care about Arctic ice levels...

      but as for the rest of us...we've got to figure out a way to reverse this trend and inevitably dangerous and expensive disaster...

    • 2 years ago
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