Two new studies say different things about Greenland’s icecap history


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The uncertainty of science: Two new studies of Greenland’s icecap suggest completely opposite histories, with one saying that Greenland was ice free at least once in the past 2.6 million years, with the other saying that the icecap covered Greenland continuously for the past 7.5 million years.

Evidence buried in Greenland’s bedrock shows the island’s massive ice sheet melted nearly completely at least once in the last 2.6 million years. This suggests that Greenland’s ice may be less stable than previously believed. “Our study puts Greenland back on the endangered ice-sheet map,” says Joerg Schaefer, a palaeoclimatologist at the Lamont-Doherty Earth Observatory in Palisades, New York, and co-author of a paper published on 7 December in Nature.

A second paper in the same issue paints a slightly different view of the ice sheet’s past stability. A group led by Paul Bierman, a geomorphologist at the University of Vermont in Burlington, found that ice covered eastern Greenland for all of the past 7.5 million years. Experts say the two papers do not necessarily contradict one another: at times, nearly all of Greenland’s ice could have melted (as seen by Schaefer’s team) while a frosty cap remained in the eastern highlands (as seen by Bierman’s group).

If all of Greenland’s ice melted, it would raise sea levels by seven metres. Models suggest that Greenland could become ice-free as soon as 2,500 years from now, depending on the concentration of greenhouse gases in the atmosphere. [emphasis mine]

This story is a perfect example of how the passionate belief in a theory (that global warming is happening, is a threat, and will melt the icecaps) can warp a scientist’s thinking. Both studies used a single drilled ice core, with the first from Greenland’s central region and the second from Greenland’s eastern region. Thus, there is no reason to say that the entire Greenland icecap had melted, as noted in the highlighted text that describes the first study. What the data merely suggests is that these two regions might have had different histories.

Instead, the article, in its effort to confirm the possibility that Greenland’s icecap could melt entirely and thus pose a threat of a big sea level rise, ignores this simple detail and struggles to justify the concept that the entire cap certainly melted in the past, even though one study suggests otherwise. This causes everyone to misunderstand the results, and draw conclusions that are uncalled for, based on the available data.

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2 comments

  • wayne

    Been watching Feynman & Penrose video’s today–and don’t want to venture down the “climate” rabbit-hole, too deeply. (I was trained in Behavior Analysis, so although not a righteous “scientist” (to some folks standards) I’m highly sympathetic to the whole Scientific Method approach.)

    A thinking-out-loud question:
    Is it the case, these people are asking & indeed, self-answering, their own “Why” questions, rather than exploring the “How” questions of “climate?”

    A multiple-repeat from me, but I think it’s on point, from a purely conceptual standpoint:

    Feynman
    “Fun to Imagine” clip
    https://youtu.be/wMFPe-DwULM
    (7:32)

  • Edward

    wayne asked: “Is it the case, these people are asking & indeed, self-answering, their own ‘Why’ questions, rather than exploring the ‘How’ questions of ‘climate?’

    Good question. Robert’s point seems to be that each of the groups of scientists were drawing conclusions based upon a single point of data. It is difficult to derive much knowledge from single data points. They have two data points that each describe a “what” answer to a question.

    I would suggest that they may be suffering from confirmation bias, in that each group may have concluded a preconceived notion about the Greenland ice by using the limited data available to them.

    Although the “how” question may be the one to answer, when it comes to global warming/temperature change/climate change/whatever, climate science still is trying to figure out the “why” part of the science.

    Not knowing “why” is why there are so many various hypotheses for the “why” of the recent “pause” in global warming.
    http://hockeyschtick.blogspot.com/2014/11/updated-list-of-64-excuses-for-18-26.html

    They clearly do not understand the basic “why” of what is going on, so it is difficult for them to begin the “how” explanation that describes the “what.”

    (The “pause” has driven climatologists to declare the occurrence of the well known phenomenon of climates in constant change — but that it is now man’s fault, yet that it wasn’t for the past millions of years. I would suggest that, as we have seen in the early 20th century and the late 19th century, the recovery from the Little Ice Age is not happening as a straight line temperature increase but has undergone other rate changes, including at least one multidecade decrease.)

    If climate science (and global warming) were so settled, then we would have answers comparable to Feynman’s “why” example in the video clip linked by wayne, above. Instead, we have people telling us that higher CO2 levels are causative of higher temperatures, even though data going back many millennia demonstrate the opposite. That unsettled argument is the basis of the man’s-fault claim for global warming.

    Yes, Gore’s chart was a deliberate lie, in his movie “An Inconvenient Truth.” Apparently the truth was too inconvenient for him, because the truth contradicts and invalidates the man’s-fault claim, and he can’t get rich selling carbon credits unless he can convince his marks — er — customers that it is man’s fault.

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