A 4000 year Greenland Temperature Record

Here’s the scenario. Greenland is warming, ice caps are melting, and eventually, New York City is flooding. Now the problem with this story. New research from the Geophysical Research Letter, a top climate research journal, estimating 4000 years of Greenland temperature anomalies, suggest nothing unusual is going on and it has been both much warmer and much cooler in the past. Here’s a summary of the study’s conclusions.

The eight researchers report that “the temperature record starts with a colder period in ‘the Bronze Age Cold Epoch’,” which they say was followed by “a warm period in ‘the Bronze Age Optimum’,” which was followed by a 1000-year cooling that began “during ‘the Iron/Roman Age Optimum’,” which was followed by “the Dark Ages,” which was followed by “the Medieval Warm Period,” which was followed by “the Little Ice Age” – which they describe as “the coldest period of the past 4000 years” – which was followed, last of all, by “the recent warming.” For comparative purposes, they also note that “the current decadal average surface temperature at the summit is as warm as in the 1930s-1940s, and there was another similarly warm period in the 1140s (Medieval Warm Period),” indicating that “the present decade is not outside the envelope of variability of the last 1000 years.” In fact, as shown in their Figure 1, a portion of which has been adapted and reproduced below, they say that “excluding the last millennium,” there were fully “72 decades warmer than the present one, in which mean temperatures were 1.0 to 1.5°C warmer,” and that during two centennial intervals, average temperatures “were nearly 1.0°C warmer than the present decade.”

And they say a picture is worth a thousand words (or 4000 years worth of data)







Roy Cordato / Senior Economist and Resident Scholar

Roy Cordato is Senior Economist and Resident Scholar at the John Locke Foundation. From January 2001 to March 2017, he held the position of Vice President for Research at the ...

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