Guest “I doubt it” by David Middleton
September 16th, 2020
Sea ice triggered the Little Ice Age, finds a new study
Takeaways>Sea ice can act as an agent of climate change on a variety of timescales and spatial scales—it’s not just a passive responder to change.
>The Little Ice Age may have arisen “out of the blue,” from internal variability within the climate system, rather than in response to an external push from volcanic eruptions or other factors.
>A far-flung pulse of sea ice may have contributed to the demise of the Norse colonies in Greenland in the 14th and 15th centuries.
A new study finds a trigger for the Little Ice Age that cooled Europe from the 1300s through mid-1800s, and supports surprising model results suggesting that under the right conditions sudden climate changes can occur spontaneously, without external forcing.
The study, published in Science Advances, reports a comprehensive reconstruction of sea ice transported from the Arctic Ocean through the Fram Strait, by Greenland, and into the North Atlantic Ocean over the last 1400 years. The reconstruction suggests that the Little Ice Age—which was not a true ice age but a regional cooling centered on Europe—was triggered by an exceptionally large outflow of sea ice from the Arctic Ocean into the North Atlantic in the 1300s.
While previous experiments using numerical climate models showed that increased sea ice was necessary to explain long-lasting climate anomalies like the Little Ice Age, physical evidence was missing. This study digs into the geological record for confirmation of model results.
Researchers pulled together records from marine sediment cores drilled from the ocean floor from the Arctic Ocean to the North Atlantic to get a detailed look at sea ice throughout the region over the last 1400 years.
[…]
CU Institute of Arctic and Alpine Research
The full text of the paper is available… And it’s very well done.
Evidence for extreme export of Arctic sea ice leading the abrupt onset of the Little Ice Age
There’s no doubt that the Maximum Holocene Arctic sea ice extent was coincident with the coldest part of the Holocene – The Little Ice Age.
Stein et al. 2017, constructed a cross-section of PIP25 curves across the Arctic from the Fram Strait to the Chukchi Sea.
All four core locations currently reflect seasonal ice cover/ice edge situations (PIP25 index 0.5-0.7), with the Fram Strait being an ice edge situation and the other three reflecting seasonal ice cover.
Two key takeaways:
- Maximum Holocene sea ice extent occurred within the past 500-1,000 years at every location.
- The current sea ice extent is higher at all of the locations than over 50% to 85% of the Holocene.
It’s very clear that the maximum Holocene Arctic sea ice extent occurred during the Little Ice Age. And this would have been accompanied by an increase in export of Arctic sea ice… However, it seems unlikely that the expansion of Arctic sea ice caused the Little Ice Age. It seems more likely that whatever caused the Little Ice Age also caused the sea ice expansion and “extreme export of Arctic sea ice.”
The paper basically concludes that sudden, extreme climate change can result from natural internal variability, without external forcing.
Reference
Martin W. Miles, Camilla S. Andresen, Christian V. Dylmer. Evidence for extreme export of Arctic sea ice leading the abrupt onset of the Little Ice Age. Science Advances, 2020; 6 (38): eaba4320 DOI: 10.1126/sciadv.aba4320
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Come up with a hypothesis (or model) and then go look for confirmation: the scientific method bass ackwards.
The history of Glacier Bay and its people illustrates nicely the ice accumulation and melting periods associated with the LIA.
The visitor center is a good place to explore this is https://www.nps.gov/glba/learn/historyculture/early-peoples.htm
For the glaciers https://www.nps.gov/glba/learn/nature/glacier-bay-s-glacial-history.htm
Of particular interest is the terminus of the glacier ca. 1680, with a meltwater stream connecting it to the ocean, and the location of Huna Tlingit habitation. Between then and 1750, the ice advanced over this habitable area, and extended out from the coast. This protrusion could not be sustained, and by the time the George Vancouver explored 45 years later, the glacier had retreated (calved/melted) 5 miles back, forming the bay.
The history there is fascinating, including status during the visit of John Muir.
I’ve been there twice, and viewed the terminus of the Marjorie and Grand Pacific Glaciers both times. I recommend the trip.
Sorry for the earlier misspelling of ‘Margerie Glacier’
And Co2 induced global warming caused the Titanic to sink.
“Trough record with bidecadal resolution based on the relative absence of the foraminifera Cassidulina teretis as an indicator shows a marked increase in sea ice and polar waters just before 1300 CE of several decades duration culminating around 1370 CE”
Moore et al 2001 also notes a profound cooling at Baffin Island in 1375, because there was a strongly positive North Atlantic Oscillation regime and it was actually very warm in Europe. So much for their Little Ice Age theory, it’s backwards.
Figure 4 A shows less sea ice during the Sporer, Maunder, and Dalton solar minima, because of negative NAO regimes.
“previous experiments using numerical climate models”
That’s an oxymoron. You run a numerical climate model precisely because you can’t do a real experiment.
Sea Ice can never start any kind of ice age, the sea ice does not form until after the oceans are cold enough. Land ice dumping into the oceans and cooling by thawing cause colder oceans that allow sea ice to even form. Again, again, look at ice core data.
“supports surprising model results suggesting that under the right conditions sudden climate changes can occur spontaneously, without external forcing”
Why the heck is this a surprise to anyone who studies natural systems? It’s called chaotic behavior and is well understood to be part of many natural systems. Only a utter fool would believe that climate (or weather) is some kind of linear response to a gas like CO2.
The 2020 Arctic Sea Ice Extent Minimum was hit a few days ago, and will rapidly increase from now.
Because a strong La Niña cycle will be in effect this year and next, the 2021 Arctic Ice Extent Minimum will be substantially larger than 2020.
BTW, the 2020 Antarctic Ice Extent Maximum will soon peak and will be around the 8th largest in 40 years.
https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/
Extraordinary claims demand extraordinary levels of proof. Vague waffle words are not proof.
Highlights and bolding are mine.
• A) Now Greenland and the North Atlantic are considered parts of Europe?
• B) Do their surprising model results include the increased levels of glaciation in Greenland and the Alps?
• C) One is curious just how a sea ice exodus from the North Pole seas causes significant portions of the world to freeze and accrete greater levels of ice?
e.g.
And this is caused by sea ice influx into the North Atlantic?
Never mind that North America was likely to be completely in sync with Greenland.
This is a two way street folks!
Perhaps, North America’s northern coastal residents should note that their local sea ice and resident icebergs may cause their towns to freeze?
Riigghht…
We need to start praying now, since it takes 300 years to be answered, but what do we pray for and who will do the praying? So many questions, so many answers – it’s all so confusing. We had a nice summer in So MO. Lots of rain and rarely over 95 degrees. In the 1950’s-80’s it was really hot w/ temps in the 100’s. Grass went dormant mid-July and our family spent a month in national parks out west. In the early 1930’s-1960’s, my grandparents spent summers in Manitoe Springs, CO. No A/C sucks.
Yes, and Eskimos were stockpiling that sea ice so again, humans are to blame!
This is getting so old…