A glacier perspective

The following images were presented by Dr. Lonnie Thompson at the latest AGU conference in California, in a powerpoint presentation. Just gives a bit of a persective on what is going on around the world. Ice is one of the first reactors to a climate change, and the pictures show that we are in a new climate. The images are from different parts of the world: the Himalays in Tibet, to the Andes in South America, Alaska, Glacier National Park, Italy, Africa, etc

thompson4.jpgthompson6-him.jpgthompson7.jpg

The next two sets are before and afters, just on different images

t8.jpg t2-p-2.jpg

t9.jpg t10.jpg

t11.jpg t12-andes.jpg t15.jpgt17.jpgthompson5.jpghimwater.jpg

Notice the height of the stick t13.jpg

Note the change in the glacier relative to the boulder

t18.jpgt120.jpg

and now:

t19.jpg t21.jpg

4 responses to “A glacier perspective

  1. Hello chris,
    Interesting stuff youve got going on here. I do know that certain (5% of the world if im not mistaken) glaciers are increasing. Why would this be? Additional precipitation due to a warmer climate such as interior antarctica and greenland? or is there another explination?

    Response- That is pretty much the story. Mostly in the interior of East Greenland ice sheet, and mainly due to a bit more snowfall in the interior (e.g Davis et al. 2005.) Most glaciers worldwide have a negative mass balance, and regional factors (like precipitation, cloud cover, local human or natural activity, or local cooling) may be playing a role in some that aren’t, but looking at a global perspective the trends are large, fast, and consistent with temperature

    Chris

  2. Hi Chris,

    Great blog! As was said earlier, there is a small percentage of glaciers with a positive mass balance. A good article describing a glacier with a positive mass balance during a warming climate is Mayo and March (1990).

    Here are some excellent links to glacier studies:

    An update to Mayo and March, 1990 is Trabant, Marsh, and Kennedy

    Dyurgerov, 2002

    Dyurgerov and Meier, 2005

    Global Outlook for Ice and Snow

    National Snow and Ice Data Center

    World Glacier Monitoring Service

    World Data Centre for Glaciology

    Here is a link to glacier classification, which lists and briefly describes parameters used to classify glaciers and gives one an idea of the tremendous diversity of glaciers:

    Illustrated GLIMS Glacier Classification Maunal

    This list of links could go on and on. There is a lot of information on the internet about glaciers.

    Response– Thanks!

  3. Glaciers in Glacier National Park have been receding since we started measuring them…in 1850.
    http://pubs.usgs.gov/of/1998/of98-031/recession.htm

    Similar for Glaciers in Switzerland.
    http://glaciology.ethz.ch/messnetz/data/aletsch.html

    IMO, glacier melt data is among the least compelling evidence for AGW.

  4. In the abstract to their 2006 paper entitled “Abrupt tropical climate change: Past and Present,” Thompson et al. stated “Three lines of evidence for abrutp tropical climate change, both past and present, are presented. First, annually and decadally averaged delta O-18 and net mass-balance histories for the last 400 and 2,000 yr, respectively, demonstrate that the current warming at high elevations in the mid-to-low latitudes is unprecedented for at least the last 2 millennia. Second, the contionuing retreat of most mid-to low-latitude glaciers, many having persisted for thousands of years, signals arecent and abrupt change in the Earth’s climate system.”

    A short essay by Eric Holthaus states “Additional recent studies by Oerlemans, Thompson, and others have confirmed that glaciers worldwide are retreating by comparing current observations with past evidence. In doing so, scientists have been able to extract a record of temperature change over the past several hundred years, which aligns with other proxy evidence, such as ice core analysis in Antarctica and Greenland, tree ring measurements from Bristlecone pine trees, and sediment cores from lakes and oceans around the world. All these data support the claim that air temperatures worldwide have been increasing at an accelerating rate over the past century.”

    The graphical summary of changes in glacier length, shown below, over the last several hundred years provided by the World Glacier Monitoring Service shows that even though as James said, retreat of many glaciers began in the middle of the 19th century, by far the majority of the retreat has occurred in the 20th century and corresponds quite well with climate change.

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