No self-respecting global warming presenter would ever miss the chance to warn the audience that higher temperatures could melt ice in places like Greenland, the melting water could lubricate the interface between ice and rock, and watch-out . the ice could increase its velocity, fall or move quickly into the sea, and cause a rapid rise in sea level. If you happen to be Al Gore, you might show us melting ice, water pouring into some moulin, and then cap it off with an image of water drowning out the World Trade Center Memorial. This story in its near infinite varieties appears on literally thousands of websites dealing with the global warming issue.
A recent article in the prestigious Science magazine has an alarming title that should thrill the greenhouse crusade: "Large and Rapid Melt-Induced Velocity Changes in the Ablation Zone of the Greenland Ice Sheet." Holy cow - it's just like Gore warned us. Throw the words `large,' `rapid,' `melt-induced velocity changes' together in a title of an article in Science and expect to get some high-level media attention. However, once we dove into this article, we found an amazing twist given the threatening title, and we could not wait to feature the piece on World Climate Report.
To begin, the research was conducted by a large team with the Institute for Marine and Atmospheric Research at Utrecht University, Netherlands; the authors state that "This work was supported by several grants from the Netherlands Organization of Scientific Research and the Netherlands Polar Programme."
van de Wal et al. focused their attention on measurements that are being made on the ice along the west coast of Greenland just north of the Arctic Circle (Figure 2). For the past 17 years, annual measurements have been made along the "K-transect" to measure movements of the ice sheet. However, they state "we started more detailed position measurements in 2005 by taking advantage of technological developments of GPS equipment and data processing. The new instruments record hourly position of stakes, which are drilled into the ice. The GPS (single-frequency) units need to be serviced only once in a year and deliver an ice velocity record with a temporal resolution of 1 day or better." To say the least, geospatial technologies are showing up everywhere in our lives from the family car to the golf course and now to our favorite transects in Greenland.
Probably the largest surprise in the article can be seen in the Figure 3 in which we can see the velocity changes at many sites over the 17-year period. The authors note that "The overall picture obtained by averaging all stake measurements at all sites for individual years indicates a small but significant (r=0.79, P < 0.05) decrease of 10% in the annual average velocity over 17 years". Despite all the talk about moulins, melting, rapid acceleration of ice, van der Wal et al. reveal that the ice movement in western Greenland over the past 17 years has . slowed significantly!
In discussing their results we find some very interesting language, to say the least. At one place they write "it has been suggested that the interaction between meltwater production and ice velocity provides a positive feedback, leading to a more rapid and stronger response of the ice sheet to climate warming than hitherto assumed. Our results are not quite in line with this view." At World Climate Report, we are far less polite, and instead of saying "our results are not quite in line with your view", we tend to say "our results suggest you are wrong"!
van der Wal et al. further write "Longer observational records with high temporal resolution in other ablation areas of the ice sheet are necessary to test the importance of the positive-feedback mechanism between melt rates and ice velocities. At present, we cannot conclude that this feedback is important." Again, we tend to say this moulin link to drowning the World Trade Center Memorial is nonsense, and the empirical evidence is overwhelmingly in our favor.
More here (See the original for links, graphics etc.)
Posted by John Ray. For a daily critique of Leftist activities, see DISSECTING LEFTISM. For a daily survey of Australian politics, see AUSTRALIAN POLITICS Also, don't forget your daily roundup of pro-environment but anti-Greenie news and commentary at GREENIE WATCH . Email me (John Ray) here
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