Arctic Temps 2°-6°C Warmer Than Today With 4.5 Fewer Months Of Sea Ice Coverage 2,000 Years Ago

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 Arctic Sea Ice Extent Higher During 1954-2001

Than Almost Any Period In The Last 9,000 Years 

During the Roman Warm Period ~2,000 years ago, sea levels were significantly higher than they are now.  Modern coastlines are 2 miles down from where they were during the Roman invasion of Britain in 43 AD, strongly implying that surface air temperatures were much warmer ~2,000 years ago compared to today.

BBC (2008)

“An archaeological dig at a Kent fort has uncovered the coastline at the time of the Roman invasion of Britain in 43AD – two miles from today’s shore.”

During that same time period, the western Arctic Ocean was covered in sea ice (>50%) only about 5 or 6 months per year (McKay et al., 2008).

By comparison, the western Arctic is covered in sea ice (>50%) about 10.5 months per year during the modern era (1954-2001), suggesting a much cooler Arctic region today.


Graph Source: McKay et al., 2008

Arctic temperatures at the beginning of the first millennium were between 2° and 6°C warmer than they are now, as paleoclimate evidence suggests summer Arctic sea surface temperatures ranged between 3°C and 7.5°C about 2,000 years ago, whereas they average about 1.1°C today.


Graph Source: McKay et al., 2008

Other authors have found Arctic region temperatures oscillated profoundly between about 3°C cooler than today and 6°C warmer than today, with sea ice fluctuating between 2 months more sea ice coverage than today and 4 months less sea ice coverage than today.


Mudie et al., 2005

“Our data show that from ∼6500 to 2600 yrs BP, there were large oscillations in [Canadian Arctic] summer SST from 2–4°C cooler than present to 6°C warmer and SIC [sea ice cover] ranged from 2 months more sea ice to 4 months more open water [than present]. The warming took ∼50–100 years and lasted ∼300 years before replacement by colder intervals lasting ∼200–500 years.”

Graph Source: Mudie et al., 2005

It is widely recognized that modern Arctic region sea ice concentrations are considerably more advanced today than they were a few thousand years ago, with most studied regions showing the increase in sea ice extent occurring “over the last centuries”.


de Vernal et al., 2013

“[W]hereas many core data show little difference between the 1953-2003 sea ice average and the late Holocene reconstruction, some cores are characterized by large differences (Fig. 4). In particular, the late Holocene data of the Chukchi Sea and the Nordic Seas off eastern Greenland, suggest much less sea ice than what was observed at the scale of the last decades. … At the Beaufort Sea sites, the variations are of limited amplitude and the estimates are close to “modern” observations, but all records show an increase of the sea ice cover over the last centuries. At the Chukchi site, the record shows large amplitude variations with a distinct trend for an increased sea ice cover towards modern values over the last centuries. … Particularly high export rates of sea ice through the East Greenland Current have been attributed to extreme AO/NAO synopses (e.g., Dickson et al., 2000; Vinje, 2001; Rigor et al., 2002). It is thus possible that the 1953-2003 mean sea ice extent along the east Greenland relates to an unusually strong positive NAO. … The early Holocene (9-6 ka) data suggest negative anomalies in the eastern Fram Strait (MSM712), the southern Labrador Sea (HU094), the Estuary of St. Lawrence (MD2220) and the northernmost Baffin Bay (HU008). These sites recording less sea ice and thus warmer conditions [than present] are all located in areas under the influence of North Atlantic waters.”

In the Beaufort Sea region of the Arctic, surface temperatures were still up to 3°C warmer than today during the late 1800s.

There was also less sea ice during this time (1887-1945), as the sea ice cover disappeared 1.1 month sooner than it does today.


Durantou et al., 2012

“Sea surface temperature [Arctic Ocean] between ∼ AD 1885–1935 are warmer by up to 3°C with respect to the average modern temperature at the coring site.
“For the period ∼ AD 1887–1945, reconstructed sea ice cover values are on average 8.3 months per year which is 1.1 months per year lower than the modern values.”
Graph Source: Durantou et al., 2012

In Southwest Greenland, the overall sea ice concentration has grown dramatically since the 1930s.  The modern (2010) extent is no lower than it was during several decadal-scale periods in the 18th century (Kryk et al., 2017).

For the Eastern Fraim Strait, the Southeast Barents Sea, and North Iceland, there was considerably less sea ice coverage (as assessed in months-per-year) during the late 1600s to early 1700s than there has been during the last few decades.


Graph Source: Kryk et al., 2017

 

Graph Source: de Vernal et al., 2013

Recently published graphs of Holocene Arctic region sea ice extent also support the conclusion that modern era sea ice is much more extensive than it has been for almost all of the last several thousand years.


Graph Source: Yamamoto et al., 2017

Graph Source: Harning et al., 2018

In sum, it is well established in the scientific literature that modern day sea ice values in the Arctic region are not unprecedented, unusual, or even remarkable relative to the last few thousand years.

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36 responses to “Arctic Temps 2°-6°C Warmer Than Today With 4.5 Fewer Months Of Sea Ice Coverage 2,000 Years Ago”

  1. Modelle: Kalter Start in den Mai 2018! Wie kalt sind die Eisheiligen? – wobleibtdieglobaleerwaermung

    […] Arctic Temps 2°-6°C Warmer Than Today With 4.5 Fewer Months Of Sea Ice Coverage 2,000 Years Ago […]

  2. JA

    “During the Roman Warm Period ~2,000 years ago, sea levels were significantly higher than they are now.
    >>>Modern coastlines are 2 miles further inland compared to where they were during the Roman invasion of Britain in 43 AD, strongly implying that surface air temperatures were much warmer ~2,000 years ago compared to today.”<<<

    Wait.. what?! how does that compute?

  3. SebastianH

    By comparison, the Arctic is covered in sea ice (>50%) about 10.5 months per year today, suggesting a much cooler Arctic region in modern times.

    Well, this borders on lying. You probably have read the paper you lifted that graph from, haven’t you? So why claim that it would depict “the Arctic is covered in sea ice (>50%)”?

    So … do you know what is pictured in this graph or did you misread the caption?

    There was also less sea ice during this time (1887-1945), as the sea ice cover disappeared 1.1 month sooner than it does today.

    Another honest mistake? It doesn’t say sooner, it says the timespan was shorter. And when we look at the location of the core that was used … surprise, about the same as in the McKay paper.

    In sum, it is well established in the scientific literature that modern day sea ice values in the Arctic region are not unprecedented, unusual, or even remarkable relative to the last few thousand years.

    They don’t really need to be. If the current decrease is largly our doing, it will continue for quite some time. As you surely know, Arctic sea ice extent was pretty stable in the 20th century and began to decrease from the late 1970s on: https://imgur.com/a/tfoSK3F (Connolly 2017)

    So image another 40 years of decrease and another … will 2100 sea levels look like at the height of the Roman Empire? What took 2000 years to build up, gone in just over a century? And you call this “not unprecedented, unusual or remarkable”?

    Well, I guess you’d need a “Day after Tomorrow” (movie) level climate change to become convinced that it really is happening. Correct? 😉

    1. AndyG55

      https://s19.postimg.cc/v8vll8mdf/old_ice.png

      Old ice is pretty close to 50%, and that’s as low as it got.

      Seen seb is bordering on DECEIT , yet again.

      “If the current decrease is largly our doing,”

      And seb drifts off into anti-science FANTASY land yet again

      ZERO evidence the slight but beneficial drop in sea ice has anything to do with human anything

      You are ABSENT OF EVIDENCE, as always, seb.

      “Arctic sea ice extent IS pretty stable “ (corrected for you)

      Arctic sea ice was about the same in the 940s as now.. so yep, apart from the extreme extent around the mid/late 1970s (coldest period in the Arctic since 1900) its been pretty stable, and is STILL in the TOP 10% of Holocene sea-ice extents.

      “So IMAGINE another 40 years of decrease and another “

      This is what seb spends his time doing…

      ….. FANTASY imagining from AGW La-La-Land.

      1. SebastianH

        Old ice is pretty close to 50%

        Have you misunderstood was is meant by 50% in the post?

        Arctic sea ice was about the same in the 940s as now.. so yep, apart from the extreme extent around the mid/late 1970s (coldest period in the Arctic since 1900) its been pretty stable, and is STILL in the TOP 10% of Holocene sea-ice extents.

        Must be something wrong with my eyes then … can’t see anything supporting this in the reconstruction of the paper Kenneth likes to cite so often:
        https://imgur.com/a/tfoSK3F

        1. AndyG55

          “Must be something wrong with my eyes then ”

          Try to keep more than one tiny thought in your head at a time, seb

          https://s19.postimg.cc/a2p8qx7oz/Arctic-_Sea-_Ice-_Changes-_Chukchi-_Sea-_Yamamoto-2017.jpg

          https://s19.postimg.cc/vgdnb299v/Arctic-_Sea-_Ice-_Holocene-_Stein-17.jpg

          https://s19.postimg.cc/v6om69bj7/Arctic-_Sea-_Ice-_Extent-_North-of-_Iceland-3000-_Years-_Moffa-_S_nchez-.jpg

          https://s19.postimg.cc/8zhof46gz/Arctic_Greenland-_Sha-17.png

          Arctic sea ice is very much I the top 10% for the Holocene, no matter if you can ACCEPT THE FACTS, or not.

        2. AndyG55

          None of those constructions bare any resemblance to temperature

          Are you now saying that Arctic sea is not driven by temperature?

          Still having trouble keeping your [snip] in a coherent rational format, I see.

          1. SebastianH

            Please just read the paper. It’s not a temperature proxy reconstruction, it is using temperature to adjust another reconstruction. The graph Kenneth likes to post (Alekseev) is a temperature proxy reconstruction however.

          2. AndyG55

            Temperature and arctic sea ice are reverse-correlated, according to seb.

            The Alekseev graph is reverse-correlated with real temperatures.

            What is your problem accepting your very own meme ???

            You weren’t LYING to yourself, were you, when you said temperature drives Arctic sea ice.

            Or are you again suffering cognitive deceit.

    2. Kenneth Richard

      Well, this borders on lying.

      And yet I don’t see any specification as to what “lie” is being told here.

      “So … do you know what is pictured in this graph or did you misread the caption?”

      The graph and text here indicate that the Arctic had 10.6 months (I generously rounded down to 10.5) with greater than 50% sea ice coverage, and 1.1 degrees C average summer temperatures during the 1950s to 2000s, whereas it had only 5 to 9 months of greater than 50% coverage during the Holocene, when SSTs averaged 3 to 7.5 degrees C, 2 to 6 degrees C warmer than present.

      Present:
      “Modern sea-ice cover in the study area, expressed here as the number of months/year with >50% coverage, averages 10.6 ± 1.2 months/year (cf. 1954–2001 data from NSIDC

      Present-day SST […] in August are 1.1°C ± 2.48°C(NODC 2001 World Ocean Atlas)

      ———-
      2,000 years ago (and earlier):
      “In the Holocene record of core [Western Arctic Ocean], sea-ice cover has ranged between 5.5 and 9 months/year, […] and summer SST has ranged from 3° to 7.5°C (Fig. 7).”

      These values are similar those found in the Mudie et al (2005) paper:

      “Our data show that from ∼6500 to 2600 yrs BP, there were large oscillations in [Canadian Arctic] summer SST from 2–4°C cooler than present to 6°C warmer and SIC [sea ice cover] ranged from 2 months more sea ice to 4 months more open water [than present].”

      1. SebastianH

        And yet I don’t see any specification as to what “lie” is being told here.

        Kenneth, you of all pedantics with words … you don’t see what you did here? So I guess honest mistake while wearing the skeptics goggles.

        Hint: “Modern sea-ice cover in the study area” and “In the Holocene record of core HLY0501-05 [Western Arctic Ocean]

        Those figures are the number of months the area where this core is located (North Alaska/Canada) experienced greater than 50% sea ice coverage. They don’t support “the western Arctic is covered in sea ice (>50%) about 10.5 months per year during the modern era (1954-2001)”. Not at all.

  4. AndyG55

    K, you forgot the Greenland region

    https://s19.postimg.cc/8zhof46gz/Arctic_Greenland-_Sha-17.png

    So we have 3 very similar reconstructions from around the Arctic showing that Sea ice is only a small mount down from its most extreme extent in the whole Holocene.

    These graphs match the temperatures from GISP quite well, further showing their correctness.

    1. SebastianH

      Glas you mention GISP. Do you know how modern temperature compare to the temperatures recorded in that dataset?

      Then add to it the 1.6°C further warming proposed by Box et. al 2009 (another of Kenneth’s favorite papers): http://polarmet.osu.edu/PolarMet/PMGFulldocs/box_yang_jc_2009.pdf

      1. AndyG55

        Oh dear, seb actually thinks temperature of ice cores are directly comparable with other reconstructions.

        So sad, so dumb, so seb. !!

        Probably also thinks you can splice instrumental records on the end.

        Mathematical ineptitude, writ large.

  5. Bruce of Newcastle

    Famously the Romans were making wine in Britain during the RWP.

    Today though I read this:

    Worldwide Wine Output Collapses To 60-Year Low, Sparks Fears Of Major Shortage

    “During the presentation, Aurand warned that global wine production collapsed in 2017, with a contraction of 8.6 percent compared with 2016 figures. In fact, global wine output dropped to its lowest levels since 1957, primarily due to poor weather conditions in the Eurozone which slashed production across the entire bloc.

    For instance, French winemakers were hit with the worst frost in 25-years, during the 2017 growing season. Vinters reported “widespread damage in Bordeaux, Burgundy, and Champagne, with some losing their entire 2017 crop,” said Wine Spectator.”

    ***

    So it looks like we may be seeing cooling setting in, and the wine industry in the more northerly parts of Europe may be heading for its own dark age.

    1. AndyG55

      “and the wine industry in the more northerly parts of Europe may be heading for its own dark age.”

      May I suggest they buy Aussie wines instead 🙂

    2. SebastianH

      2017 was bad because of a late April frost in Central Europe. 2018 looks much different though. More sunshine days than last year and no frost yet. So might become a good wine year.

      During The 800s-1300s AD, Wine Grapes Were Grown At Latitudes Where Polar Bears Now Roam

      What a tasty wine that must have been …

      1. AndyG55

        They would have been cool climate wines.

        Rieslings, Pinot, Sav Blanc sort of white wines, so yes, can be very tasty.

        Some of the wines grown in Tassie are “ab fab” !!

        You seem to be showing you UNAWARENESS of wines , now.

        Your UNAWARE becoming a VERY long list !!!

        Perhaps when you grow up you “might” become more aware.

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