Alpine Glaciers "disappeared 7000 years ago"

A new study on Alpine glaciers has shown that the recent melting since the lowest point of the "Little Ice Age" in the 17th Century is not extraordinary in the context of climate change since the end of the last Ice Age:

The Alpine glaciers are shrinking, that much we know. But new research suggests that in the time of the Roman Empire, they were smaller than today. And 7,000 years ago they probably weren’t around at all. A group of climatologists have come up with a controversial new theory on how the Alps must have looked over the ages. He may not look like a revolutionary, but Ulrich Joerin, a wiry Swiss scientist in his late twenties, is part of a small group of climatologists who are in the process of radically changing the image of the Swiss mountain world. He and a colleague are standing in front of the Tschierva Glacier in Engadin, Switzerland at 2,200 meters (7,217 feet). "A few thousand years ago, there were no glaciers here at all," he says. "Back then we would have been standing in the middle of a forest." He digs into the ground with his mountain boot until something dark appears: an old tree trunk, covered in ice, polished by water and almost black with humidity. "And here is the proof," says Joerin.

Link to article This disappearance of glaciers coincides, obviously by chance, with the Holocene Maximum previously mentioned.

9 Comments

  1. John G. Bell
    Posted Jun 10, 2005 at 10:56 AM | Permalink

    This is revolutionary. It is amazing what you can discover out in the real world by looking about your feet. Put a smile on Feynman.

    OT – Might the fact that it was published in Der Spiegel indicatate a climate change in groàƒŸer Deutschland. Not that Der Spiegel was ever green.

  2. Dave Dardinger
    Posted Jun 10, 2005 at 4:13 PM | Permalink

    In the article it says, “But there are critics. Like Oetzi, the 5,300 year old Stone Age man whose body was found in the Oetz Valley Alps. After all, how could his corpse have remained intact if the ice receded again and again?” Since they also say the warmest period was 7000 years ago and the coldest in the little ice age, I wonder what exactly the complaint is? As climate was cooling again, it’s quite logical for a body to be frozen and covered with ice and then not have been uncovered by lesser warmings until recently. If I recall, one of the questions when the body was first discovered was how it could still be around when it should have been moved downhill with glacial movement and have long ago been melted. The reason given was that the body was in a saddle area (pass) and the ice to pretty much have remained where it was without much movement. This sort of area, being at the top of the glacier would be the coldest and thus the last to warm with climate.

    Note that this differs somewhat from the situation with the trees from thousands of years ago when they had to be gradually dug up from hillsides before being incorporated into moving glacial ice.

  3. Douglas Hoyt
    Posted Jun 10, 2005 at 6:58 PM | Permalink

    I think the most important comment in the Der Spiegel article is:
    “For more than 50 per cent of the time during the last 10,000 years, the [alpine] glaciers were smaller (and shorter) than today”, Joerin wrote in a paper which he co-wrote with Christian Schluechter, his PhD supervisor.
    In other words, there is nothing unusual with today’s climate.
    The upcoming article is:
    Joerin, U.E., Stocker, T.F., and Schlüchter, C. (2005). Multi-century Glacier Recessions in the Swiss Alps during the Holocene. submitted to Geophys. Res. Lett.

  4. Peter Hearnden
    Posted Jun 11, 2005 at 4:06 AM | Permalink

    I do wonder why everyone posting to this thread is falling over themselves to both unquestioningly accept this work and promote it. Science or motive? You can explain for yourselves. I wouldn’t dsimiss this study btw.

    What really interest me though is why it is warm now (good to see everyone accept that btw). There is probably nothing, amazingly, unusual about the present day warmth (yet…) but part of the reason for the warmth (and the rate of warming) undoubtedly is. That no one mentions that that part is us is hardly surprising to me anymore.

    Re #2. So, Dave, it’s warmer now that at any time for the last 5300 years? Or just in that area? If that then is it possible that just Europe was warm 7000 years ago too?

    OK, unleash the dogs….

  5. Jerry Brennan
    Posted Jun 11, 2005 at 8:53 AM | Permalink

    See also: http://archives.cnn.com/2000/WORLD/europe/10/23/iceland.glacier/index.html

  6. Posted Jun 11, 2005 at 4:11 PM | Permalink

    Of course we skeptics have a hidden agenda Peter. By the way here is a nice link of the length of the alpine Aletsch glacier of the last two millennia

    http://www.klimanotizen.de/html/newsletter_4.html

    (by the critics Wilfried Haeberli and Hanspeter Holzhauser!)

  7. Dave Dardinger
    Posted Jun 11, 2005 at 7:35 PM | Permalink

    Re #4

    There are various possibilities, including the warmer position. While generally smaller glaciers equilibrate in times measured in decades, larger ones take much longer. I don’t know the details on the glacier Oetzi was found in, so I don’t know how much cover he might have had which had melted or evaporated off. Generally speaking the glaciated regions of the earth have been warming (on average) since the end of the last ice age, and as reserviors of coldness have decreased the excursions to warmer local temperatures are more likely. IOW, whether whatever warming has occured recently has a man-made component or not, it’s capable of warming things more for a given forcing than in the past when there was more ice present to buffer the warming.

    Of course the ocean is the largest heat buffering system by far, so I suppose checking to see what the deep oceans have done temperaturewise over the past few thousand years would be a good thing to check.

    But getting to your initial question, It’s quite possible for something to be exposed or melted out of a frozen area whether the temperature has warmed or not. Ice flows and frozen water can still sublimate at quite cold temperatures and will eventually leave barren ground if there’s no precipitation. As I said earlier Oetzi was near a saddle or pass, but I’m not sure if it was shown he was where he’d been buried or not when he was found. He might have slowly moved until he was in a location where he could melt out. Also, in open areas near a pass, snow might not accumulate much because of wind blowing it downhill.

    I just went and read some background on his finding (see: http://www.mummytombs.com/mummylocator/featured/otzi.discovery.htm )
    and here’s an interesting pull-quote “When the authorities arrived, they were well aware that the glacier had been melting. Three weeks earlier, the bodies of a man and woman who had gone hiking in 1934 and never returned had been discovered. For this reason, they, like the Simons, assumed that the person had died in a climbing accident.

    So while we might conclude it’s the warmest it’s been since 1934, I’m not sure we can say it’s the warmest in 5300 years.

  8. Knut Knutsen
    Posted Jun 20, 2005 at 4:26 AM | Permalink

    Re #7. The absence of glaciers in the early to mid holocene time is easily understood, as this was a time of higher solar insolation due to the Earth´s´orbital configuration (Earth was closer to sun in northern summer than now). hence the reasons for glacier meltback was different than the factors governing the current melting. The available ocean proxy data also shows that the mid-to high latitude regions were warm during summers at the same time, whereas the tropics were slightly cooler (see e.g. paper by Kim et al. in Quat. Sci Rev 2004). Thus the warming that melted glaciers then was not global in extent, and was caused by other mechanisms than the ongoing warming.

  9. TCO
    Posted Sep 19, 2005 at 9:24 PM | Permalink

    Some good comments by both sides here. I do wonder if this method of finding things in glaciers could become another proxy.

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