STUDY: Before Warming A Bit, Antarctica Underwent 1,900 Years Of Cooling
By Paul Homewood
Michael Bastach brings news of a new paper which looks at temperature trends across Antarctica in the last two millennia.
Antarctica went through a 1,900-year cooling trend before warming up a bit in the last century, according to a study showing that the South Pole has been much warmer in the past.
The current warming is not unusual for the South Pole, according to the study led by Italy-based scientist Barbara Stenni, which used ice cores to reconstruct Antarctic temperatures over the past two millennia.
“Our new reconstructions confirm a significant cooling trend from 0 to 1900 CE [Common Era] across all Antarctic regions where records extend back into the 1st millennium, with the exception of the Wilkes Land coast and Weddell Sea coast regions,” Stenni and her colleagues wrote.
The study also found that “the warmest period occurs between 300 and 1000 CE, and the coldest interval occurs from 1200 to 1900 CE,” suggesting that today’s relatively warm Antarctic temperatures are not unprecedented.
Source: www.clim-past.net/13/1609/2017/cp-13-1609-2017.pdf
Antarctica has confounded climate scientists for decades.The continent’s inhospitable conditions make it hard to collect data from the region and historical records are hard to come by. Scientists can use ice cores, but new evidence suggests there are problems with relying on such methods.
Either way, Antarctica has shown few signs of global warming, defying climate model predictions that the region would warm as greenhouse gases accumulated in the atmosphere.
That’s not been the case for the entire continent.
A 2016 British Antarctic Survey study found that the Antarctic Peninsula had undergone a cooling trend since the 1990s, due to a confluence of the hole in the ozone layer, sea ice, and westerly winds.
The media has breathlessly reported on the “unstoppable disintegration” of Antarctica’s ice sheet, despite the lack of a clear man-made warming signal in the South Pole. Stenni’s study puts the recent warming in context.
“Since 1900 CE, significant warming trends are identified for the West Antarctic Ice Sheet, the Dronning Maud Land coast and the Antarctic Peninsula regions,” Stenni wrote. “Only for the Antarctic Peninsula is this most recent century-scale trend unusual in the context of natural variability over the last 2000 years.”
However, Stenni admits the “absence of significant continent-scale warming of Antarctica over the last 100 years is in clear contrast with the significant industrial-era warming trends that are evident in reconstructions for all other continents (except Africa) and the tropical oceans.”
This lack of warming “is not in agreement with climate model simulations, which consistently produce a 20th-century warming trend over Antarctica in response to greenhouse gas forcing,” Stenni wrote.
The graphs tell the story better than I can.
But what is also noticeable is that the temperature spike we have seen towards the end of the 20thC in West Antarctica is not uncommon.
We already know that the Arctic was warmer in the recent past than now, and now we find the same is true in the Antarctic.
The idea that the small amount of warming since the Little Ice Age is either dangerous or somehow unnatural is becoming increasingly unsustainable.
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NOT A LOT OF PEOPLE KNOW THAT 
It is getting harder and harder to imagine exactly what kind of evidence it will take to convince the general public that the science is NOT settled. On the other hand, the main stream media is doing a great job of keeping this kind of evidence well hidden.
The general public really don’t care. The ones who do, the Greenwashed, won’t believe anything, other than it’ll only get worse & it’s your fault.
Does anyone else remember that ‘global cooling’ was the overriding concern in the late 1950s and 60s?
Of course, someone will look at the graphs and say, ‘well look! West Antarctica just suddenly warmed up 1 C. It’s never warmed up that fast before.’
Really, looking at the graphic, looks like there are more than a dozen instances of it warming up 1 C, or more, in the record.
There is no visual evidence here that the current bit of warming has broken the long-term cooling trend.
. . not to mention that the Antarctic Peninsula has just cooled just over 1 C during the last 2 decades.
We do all realise, don’t we, it’s our grandchildren who will be forced to deal with the consequences of the bungled CAGW fallout. Like paying back global national debts to rent seeking socialists.
Oh! the irony, it stings.
Current piece by Steve McIntyre adds to the content here.
It was Steve McIntyre along with Ross McKitrick who pulled the plug on CRU which became “Climategate”. They got the emails between Micky Mann and the rest colluding to promote “fake science.”
Wrong. It was broken on The Air Vent, not ClimateAudit.
This all reminds me of the fuss about the existence or non-existence of a supposed mediaeval warm period. Does it really matter? Even if there was an MWP, it would only mean that large and rapid temperature changes can be down to natural causes. It does not mean that all, or any such changes must be natural, especially any in recent times. On the other hand, if there was no MWP, it does not mean that there can’t be any natural large and rapid temperature changes. It merely means that one did not occur at that time.
While we are talking about the Antarctic and the MWP, it seems appropriate to discuss Lonnie Thompson’s temperature reconstruction based on ice core data which figures so prominently in Al Gore’s “An inconvenient truth”. As AG so gleefully points out, the warmings and coolings of centuries ago appear to be little more than blips when compared with the modern warming. What he fails to address, is the fact that the modern “data” appears to be much more noisy than the earlier “data”. Clearly, there is some sort of smoothing going on. This could be down to diffusion in the ice cores concerned or to dating errors in the different ice core samples. We should also note that if we had some exceptionally warm years, there might have been no ice formed at all. Some might even have melted. Whatever the cause, such smoothing would almost inevitably result in lowering the peak of any MWP mountain and raising the apparent levels of the surrounding plains or valleys. This would make any MWP appear to be somewhat smaller than it otherwise would do.
It seems as though our palaeoclimatologists are skating on very thin ice 😉
Of course it matters. The “proof” of AGW is that it couldn’t be anything else other than CO2 and that what we are seeing now is unusual. If you show that the same thing has happened before without C)2 then that “proof” falls away. That is why the Climategate emails showed a fair bit of worry from Alarmists about the MWP and statements about getting rid of it. That is why a number of Alarmists have tried to show either that it didn’t happen or it wasn’t global.
The MWP shows that the current state of climate science is rudimentary, and that climate scientists don’t understand very much at all about our climate. That means they cannot claims “settled science”.
The importance of not just the Medieval Warm Period, the Roman Warm Period, the Minoan Warm Period and the Holocene is that it provides a comparison with today’s claimed runaway warming.
The Vikings colonized Greenland and farmed it. It is not being farmed at the moment so I guess it was warmer then. The Romans grew grapes and produced wine in Newcastle – the presence of Vine Street being a clue. It is too cold to produce grapes during this ‘exceptional warming’.
I don’t have examples for the earlier periods other than warm periods are times of great expansion for the human race as opposed to the contraction caused by the Little Ice Age.
New paper on 3000 years of climate change in Europe
https://www.nature.com/articles/s41467-017-01884-8
Discussion here on the MWP, LIA etc
As the green activists, “scientists”, scamsters and bandwagon politicians would say: “who cares? As long as the donations, grants, subsidies and taxes continue to flow”.
I think for the activists it is about what you use the “science” for, rather than grants. The science allows them to move away from free markets, low taxes and choice to centralised government and centralised control, and the regulation and/or destruction of things they don’t like.
The thing that amazes me about the whole thing is how quickly we went from “here’s what might be a problem” to “here’s the only solution”.
The amount of work done on the solution was almost non-existent, and if anything even poorer than the climate research.
As long as the people who count (politicians, media and academia) are on message with the narrative they couldn’t care less about “the barbarians at the gates”. And when we go into a cooling period, they’ll use those structures of power to continue to lie, deceive and obfuscate.
Reblogged this on Climate Collections.