Today, the region north of Svalbard is encrusted with sea ice for all but a few weeks per year and summer sea surface temperatures (SSTs) hover near 0°C. Scientists (Brice et al., 2020) have determined this same region had sea ice-free conditions last about 10 months per year while SSTs reached 4°C just ~4100 years ago.
In early September, 2019, Arctic explorers once again needed to be rescued from the “disappearing” sea ice that had captured their ship in central Svalbard. This region is presently free of sea ice for only a few weeks per year (late August).
Image Source: electroverse.net
Observational measurements (Rösel et al., 2018) of the sea ice north of Svalbard indicate the ice has actually been significantly thicker in recent years (1.56 to 1.65 meters in 2015, 2017) than it was in 1955 (0.94 of a meter).
Image Source: Rösel et al., 2018
A study site northeast of Svalbard (Brice et al., 2020) reveals today’s sea surface temperatures of “<0°C” are at least 4°C colder than they were just a few thousand years ago, when the Arctic was sea ice free for all but “a couple of months” every year. Notice the graphics that show today’s sea ice monthly duration (~11 months per year) and summer sea surface temperatures (zero degrees Celsius) are among the highest and lowest (respectively) of the Holocene.
Image Source: Brice et al., 2020
Per Brice et al. (2020), the much warmer Arctic climate and absence of sea ice reached an “optimum” during “the interval around 3000-2000 cal yr BP” such that late Stone Age human settlements north of Svalbard were “feasible”.
5 responses to “New Study: Arctic Waters Were 4°C Warmer Than Today And Nearly Sea-Ice Free Year-Round ~4100 Years Ago”
The Arctic waters are colder now because of Man Made Global Warming.
A paper from 1953:https://archive.org/details/glaciervariation00ahlm/page/22/mode/2up
The climate then was not stable. Periodic change due to currents?
Winter temperatures varied 8 degrees during a period of Years.
[…] Brice et al., May 28, 2020 in […]
Great work, Pierre, thank you.
It’s very disturbing that Brice et al. 2020 do not shout much more loudly and clearly their important discovery that 1950 (0 years BP) sea-surface temperature and sea-ice cover at their core site were the lowest and highest, respectively, of the last 2,000 years and possibly even 10,000 years (your two charts above, extracted from their fig. 6), and that their core shows no evidence of the modern average GLOBAL warming (from 1910, e.g. HadCRUT chart). Even more strangely they conclude (p. 11): “Hence, almost all data from the Nordic Seas and Scandinavia seem consistent both on land and at sea, showing that the last two millennia have been regionally the coldest of the Holocene … EXCLUDING THE RECENT ANTHROPOGENIC WARMING” (my capitals). How bizarre is that? Not only do they not ‘see’ the warming in their core, but they also ASSUME it is man-made (no citations provided). Again on p. 11: “The trend towards colder conditions that is inferred over the last 2000 yr of the Holocene, prior to the ongoing anthropogenic warming, in the northwestern Barents Sea …”, which their core does not show.
Evidently Brice et al. agree with Greta and Gore that ‘The Science is Settled’ and CO2 is warming our planet. Big mistake …
I note that the lead author’s institution, GEOTOP (Canada), has fallen into the same trap …
Google indicates that GEOTOP receives funding from the Canadian government. If so, Canadian citizens are paying, through taxation, for their own anti-CO2 indoctrination.
Roger, I partly agree with you, except for your three pillars paper #1 and #2 big mistakes.
#1 Solar activity levels drive the climate via TSI, not cosmic rays, and #2 the 80-year lag isn’t real.
This paper’s 4C higher level 4100ya coincides with Vinther et al’s 1.2C Greenland 20yr reconstruction temperature anomaly spike (from zero).
Prior to 4100 years ago, Greenland enjoyed 6kyr of above-average temperatures, Fig. 4 (@ red circled #2), then cooled for 2kyr until post-LIA warming.
The whole earth warms/cools in the 92-95 sunspot number range.