Evidence for the Medieval Warm Period on the SE Greenland Shelf

Posted: June 4, 2016 by oldbrew in Analysis, climate, research

Kangerlussuaq Fjord, Greenland [image credit: notsogreen.com]

Kangerlussuaq Fjord, Greenland [image credit: notsogreen.com]

CO2Science summarises another study pointing to more ‘inconvenient’ data concerning the Medieval Warm Period.

In the introduction to their enlightening study, Miettinen et al. (2015) write that they “reconstructed August sea surface temperature (aSST) and April sea ice concentration (aSIC) at sub-decadal temporal resolution based on diatom assemblages found in sediment core MC99-2322 from the Kangerlussuaq Trough, SE Greenland shelf in order to investigate the variability of summer sea surface conditions along with possible forcing factors on the climatologically sensitive SE Greenland shelf during the last 1130 years.

“As shown in the figure below, this work revealed, as the five researchers report, that “around 1000 C.E., aSST rises as much as ~2.4°C from 4.8°C (~995 C.E.) to the absolute record maximum of 7.2°C (~1050 C.E.) in the time span of only ~55 years, indicating a forceful onset of the warm conditions in the area.”

And they go on to state that “the clearly discernible warm period ~1000-1200 C.E. with the mean aSST of 6°C represents the warmest interval of the 2900 year long record [our italics].”

It is also illuminating to note that the atmosphere’s CO2 concentration over the 1000-1200 C.E. period of maximum warmth on the SE Greenland Shelf was only about 280 ppm, while today it is over 400 ppm and growing ever higher.

Yet global temperatures still have a considerable way to rise before they reach the level that prevailed during the record-breaking Medieval Warm Period, which further suggests that the atmosphere’s CO2 concentration has a much weaker impact on global near-surface air temperatures than what is currently claimed to be the case by the world’s climate alarmists.

From Miettinen et al 2015 [via co2science.org]

From Miettinen et al 2015 [via co2science.org]

High-resolution reconstructed August sea surface temperatures (aSST) from Kangerlussuaq Trough, SE Greenland shelf, over the interval 870-1910 CE.

Adapted from Miettinen et al. (2015).
Paper Reviewed: Miettinen, A., Divine, D.V., Husum, K., Koc, N. and Jennings, A. 2015. Exceptional ocean surface conditions on the SE Greenland shelf during the Medieval Climate Anomaly. Paleoceanography 30: 1657-1674.

Source: Evidence for the Medieval Warm Period on the SE Greenland Shelf | CO2Science

  1. oldbrew says:

    Vikings grew barley in Greenland

    ‘The Greenland climate was a bit warmer than it is today’

    Then the Little Ice Age came along and forced them out, it seems.
    ‘The cold climate may have finished off not only the barley but also the Vikings on Greenland themselves.’

  2. E.M.Smith says:

    Interesting that our recent dramatic rise bareley gets us out of the 1800s down spike and about on par with 1500 A.D.

    The diatom use as proxy is OK for local temp, but a companion oxygen isotope measure would have illuminated global state better.

  3. oldbrew says:

    Whatever caused the Medieval Warm Period, it wasn’t high CO2 levels.
    So looking elsewhere, what have we got? Apart from the Sun, lack of theories.

    That makes the Sun the favourite.
    The MWP lasted ~200 years which seems to rule out a sudden event of some kind.
    The oceans would have warmed and global circulation would have had plenty of time.

    Scandinavian research (Esper et al) found this:


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