Is Arctic Ice Loss Driven by Natural Swings?

An interesting new paper on Arctic sea ice has just been published. According to the conclusions of “Influence of high-latitude atmospheric circulation changes on summertime Arctic sea ice“:

Although positive feedbacks between sea ice and the Arctic circulation exist, we find that these are small during summer. Instead, circulation variations over the Arctic have been a significant factor in driving sea-ice variability since 1979, and have had a non-trivial contribution to the total surface temperature trend over Greenland and northeastern Canada39 . The potentially large contribution of internal variability to sea-ice loss over the next 40 years reinforces the importance of natural contributions to sea-ice trends over the past several decades. The similarity of high-latitude circulation variability associated with sea-ice loss to the teleconnections with the tropical Pacific suggests a contribution of sea-ice losses from SST trends across the tropical Pacific Ocean. Decadal trends in the hemispheric circulation are an important driver of Arctic climate change, and therefore a significant source of uncertainty in projections of sea ice. Better understanding of these teleconnections and their representation in global models under increasing greenhouse gases may help increase predictability on seasonal to decadal timescales.

As you may already be able to imagine, this paper (PDF as submitted) is already the source of considerable controversy! Firstly let’s take a look at an overview of the paper from the University of Washington, entitled “Rapid decline of Arctic sea ice a combination of climate change and natural variability”:

“The idea that natural or internal variability has contributed substantially to the Arctic sea ice loss is not entirely new,” said second author Axel Schweiger, a University of Washington polar scientist who tracks Arctic sea ice. “This study provides the mechanism, and uses a new approach to illuminate the processes that are responsible for these changes.”

[First author Qinghua] Ding designed a new sea ice model experiment that combines forcing due to climate change with observed weather in recent decades. The model shows that a shift in wind patterns is responsible for about 60 percent of sea ice loss in the Arctic Ocean since 1979. Some of this shift is related to climate change, but the study finds that 30-50 percent of the observed sea ice loss since 1979 is due to natural variations in this large-scale atmospheric pattern.

Now let’s take a look at another overview of the paper, this time from Roz Pidcock at Carbon Brief and entitled “Humans causing up to two-thirds of Arctic summer sea ice loss, study confirms”:

Rising greenhouse gas emissions are responsible for at least half, possibly up to two-thirds, of the drop in summer sea ice in the Arctic since the late 1970s, according to new research. The remaining contribution is the result of natural fluctuations, say the authors.

The paper, published today in Nature Climate Change, confirms previous studies which show how random variations in the climate have acted to enhance ice loss caused by rising CO2.

Importantly, the authors state clearly in the paper that their work does not absolve human activity as a driver of Arctic sea ice loss. A News and Views article that accompanies the paper, by Dr Neil Swart from Environment and Climate Change Canada, adds:

“The results of Ding et al. do not call into question whether human-induced warming has led to Arctic sea-ice decline — a wide range of evidence shows that it has.”

There has already been much debate about the paper on Twitter! Here’s the “scientific” edition:

 

and here’s the “skeptical” edition:

 

Needless to say Anthony Watts swiftly stepped up to the plate on the “skeptical” side of the “debate” with a guest article on his blog by David Middleton entitled “Arctic ice loss driven by natural swings, not just mankind: study” which begins by quoting a similarly titled Reuters article by Alister Doyle:

FILE PHOTO: An undated NASA illustration shows Arctic sea ice at a record low wintertime maximum extent for the second straight year, according to scientists at the NASA-supported National Snow and Ice Data Center (NSIDC) and NASA. NASA/Goddard's Scientific Visualization Studio/C. Starr/Handout via Reuters/File Photo
FILE PHOTO: An undated NASA illustration shows Arctic sea ice at a record low wintertime maximum extent for the second straight year, according to scientists at the NASA-supported National Snow and Ice Data Center (NSIDC) and NASA. NASA/Goddard’s Scientific Visualization Studio/C. Starr/Handout via Reuters/File Photo

Natural swings in the Arctic climate have caused up to half the precipitous losses of sea ice around the North Pole in recent decades, with the rest driven by man-made global warming, scientists said on Monday.

The study indicates that an ice-free Arctic Ocean, often feared to be just years away, in one of the starkest signs of man-made global warming, could be delayed if nature swings back to a cooler mode.

Natural variations in the Arctic climate “may be responsible for about 30–50 percent of the overall decline in September sea ice since 1979,” the U.S.-based team of scientists wrote in the journal Nature Climate Change.

David embellished his article with some “humorous” asides such as:

This is the worst of the worst catastrophes in the world! Oh, it’s crashing … Oh, the humanity! Honest, I can hardly breathe. I’m going to step inside where I cannot see it.”

Please say it ain’t so!!!

“The melt of the Arctic is disrupting the livelihoods of indigenous peoples and damaging wildlife such as polar bears and seals while opening the region to more oil and gas and shipping.”

Eskimos, seals and polar bears!!! Oh My!!! And more oil and gas shipping!!! Aiiieeee!!!!
Eskimos, seals and polar bears!!! Oh My!!! And more oil and gas shipping!!! Aiiieeee!!!!

which some of us took exception to:

David – An Arctic indigenous person of my acquaintance asks me to tell you to “go f(r)@ck yourself”!

What should I reply on your behalf?

No answer has yet been received to that (im)pertinent question!

All this excitement in the Twittosphere and elsewhere leads one to wonder whether Ding, Schweiger et al. saw (or should have seen?) all this coming, and if so what might have been done differently? In any event this story is set to run and run and run and……

 

[Edit – March 18th]

I tried this Google search this morning:

Google-NaturalSwings-20170318

38,000 results. We’re number 4. If you repeat the exercise please feel free to experiment with the search phrase(s) you employ. Make sure to only click on the link that leads you back here!

Watch this space.

 

Alternative Points of View – Scientific

William M. Connolley (AKA Stoat)

Without being able to pick any obvious holes I feel somewhat uncomfortable with that; the idea that September ice depends just on JJA circulation doesn’t feel at all right. Having decided that, though, they then run a variety of model experiments, for example “nudging” the circulation back to re-analysis, with and without an ocean-ice model underneath. And the result seems to be that it is mostly the circulation forcing the sea ice, rather than the sea ice changes forcing the atmosphere. This kinda-fits the “information flow” meme from way back so I should be prepared to accept that mostly. Having done that they then convince themselves that most of the circulation changes that matter to the ice are not GW forced, and so must be natural variability; and hence the conclusion. If you took all of this at face value then they’d have solved one of the puzzles, that on the whole models show much less ice decline that reality. But of course if the decline is substantially a freak of variation, not forced, that would fit.

The flaw in this overall, without looking at the details, is that it’s hard to see a near-40-year trend and being so much natural variability. That seems to be asking for an awful lot of one-way variation.

 

The Science Media Centre

Prof. Andrew Shepherd, Director of the Centre for Polar Observation and Modelling at the University of Leeds, said:

“According to this new research, the dramatic decline in Arctic sea ice that we have witnessed over recent decades is primarily due to anthropogenic (man-made) climate warming.

“Although this finding may not come as a surprise, being able to separate this from the effects of natural climate variability is an important step forwards, and paves the way for an improved understanding of what we should expect in future decades.”

Dr Ed Hawkins, Climate research scientist at the University of Reading, said:

“Recent summer Arctic sea ice extents have all been amongst the lowest on record but this is not necessarily all due to warming global temperatures – part of the sea ice decline is also because of changes in the atmospheric circulation.

“It is challenging to determine how much of the change in the circulation is itself due to warming temperatures, but this study suggests that a substantial fraction is due to natural fluctuations.

“Looking ahead, it is still a matter of when, rather than if, the Arctic will become ice-free in summer, but we expect to see periods where the ice melts rapidly and other times where it retreats less fast.”

 

Archived Alternative Points of View – “Skeptical”

Colin Fernandez at the Daily Mail

HALF of Arctic ice loss is driven by natural swings and not global warming, controversial study claims

  • Decline in ice cover due to ‘random’ and ‘chaotic’ natural changes in air currents
  • The rest has been driven by man-made global warming, scientists said

 

Colin Fernandez’ Daily Mail article reproduced at the “Global Warming Policy Forum

The Arctic icecap is shrinking – but it’s not all our fault, a major study of the polar region has found. At least half of the disappearance is down to natural processes, and not the fault of man made warming.

Part of the decline in ice cover is due to ‘random’ and ‘chaotic’ natural changes in air currents, researchers said.

The rest has been driven by man-made global warming, scientists said.

The research means that although it is widely feared that the Arctic could soon be free of ice, this could be delayed if nature swings back to a cooler cycle.

 

Colin Fernandez’ Daily Mail article reproduced at Mark Morano’s “Climate Depot

Study in journal Nature: HALF of Arctic ice loss driven by natural swings — not ‘global warming’

 

David Middleton at Anthony Watts’ “Watts Up With That

From the No Schist, Sherlock files…

Perspective: NSIDC Arctic Sea Ice Index Interactive Graph

The five earliest years of data plot near +2 standard deviations. The five most recent full years of data plot near or just outside of -2 standard deviations. Ding et al., 2017 conclude that up to half of the difference is due to the NAO and other natural climate fluctuations.

 

Paul Homewood at “Not a Lot of People Know That

Shock news! Scientists discover natural climate cycles.

Astonishingly though, the study makes no mention of the Atlantic Multidecadal Oscillation, which also has a significant effect on Arctic sea ice extent.

Since the late 1970s, the AMO has moved from the coldest point of its cycle to its highest, coinciding with a decline in Arctic sea ice coverage.

 

Patrick Michaels and Paul “Chip” Knappenburger at “The Cato Institute“:

Considering that the climate models are already performing poorly as it is, the new finding means that they are actually faring even worse than has been generally realized. And accounting for this strengthens the case for a lukewarming future from greenhouse gas emissions.

Ring up another strike against the climate models, and another reason why basing government policy on their output is a bad idea.

13 thoughts on “Is Arctic Ice Loss Driven by Natural Swings?

  1. I was very disappointed when I discovered that a virgin, with a fresh bay leaf in her mouth, could tell a falsehood. I was even more disappointed when I discovered computer models were even more at the mercy of of their “priests”, than the virgins at the Temple of Delphi.

    All models are wrong, some are useful, some will save your life. CMIP5 is like a virgin with a fine, large bay leaf in her mouth. She will speak nonsense if asked the wrong question.

    Suggested Questions:
    1)Has AGW changed global atmospheric circulation patterns?
    2) Do AGW induced atmospheric circulation patterns allow more (latent) heat into the Arctic?

    My favorite virgin is sitting under the bay tree muttering things that sound like, “AGW is very noisy.” In the best Delphi tradition, it does not answer either of the questions, and yet it answers the big question; Does increased forcing of a large feedback system with multiple feedback loops including significant “lags” and “stores” increase the noise? It does, and we have known this since “Industrial Dynamics” by Jay Forester.

    With AGW, I would expect to see more intense storms, more intense decadal variations such as El Nino, and more intense multi-decadal oscillations. In short, higher levels of “natural variation” are indicative of higher levels of AGW.

  2. What does this article in Nature say? I can’t access it.
    From the abstract and what I read here, it seems to be saying ‘warming can come from the Pacific.”
    yah?
    The oceans are warming.

    1. Tommy – See the new PDF link above. From the introduction:

      In this paper, we examine the contribution of the atmospheric circulation to Arctic sea-ice variability by utilizing an atmospheric general circulation model (ECHAM5) coupled with a simple ocean–sea-ice model in which the atmospheric circulation field is nudged to observations. Specifically, we explore how the high-latitude summertime atmospheric circulation impacts the September Arctic sea-ice extent, and estimate to what extent changes in atmospheric circulation explain the observed sea-ice loss of the past few decades.

      In a bit more detail:

      To examine the physical linkages, we focus on the connection between September sea-ice extent and the preceding summer (June–July–August, JJA) atmospheric circulation. We choose this preceding 3-month window because sea-ice extent anomalies have a ∼3-month decorrelation timescale , and previous studies have shown a strong link between summer circulation and sea-ice variability. We focus on physical mechanisms, analysing temperature, humidity, and downward longwave radiation (DLR), all of which are affected by atmospheric circulation and, in turn, affect sea-ice concentration. A key player is the radiation balance, which dominates the surface energy balance controlling the growth and melt of Arctic sea ice.

      I suppose one’s first question “of substance” might well be is “a simple ocean–sea-ice model” up to the task in hand?

      1. Thanks Jim. I’ll look at this paper in more detail later, but at first glance, it seems to verify GW effect on Arctic. It’s a fascinating paper in so many ways though. I can’t see the interpretation the deniers are giving it, and I can’t see how the researchers can call those natural variations in the troposphere. Everything I ever read is that the poles are warming fastest. Probably because the heat of the overall atmosphere gets shunted there by planetary dynamics (eg. maybe the shape, the spin, the flatter poles), via the ‘atmospheric circulation’.
        Also, the jet stream is said by many to be changing. That may be tied to El Nino, a natural variation, but many predict El Nino’s will change in frequency of occurrence due to GW.
        …. and so on.

  3. Climategate 3 !!! Wrote in ASIF earlier that I reckoned the greatwhitecon would be disturbed from its lair by trollish noises in cyberspace.

  4. Jim,

    Just got the time to review sea ice. I notice that Cryosphere Today is down and has been for ages. Do you remember what sea ice index we used for our bet, was it Cryosphere Today? I have a feeling it was 1 million kmsq for that index.

    Chris

    1. Welcome Chris,

      Long time no hear, speak or see! How’s things in your neck of the woods?

      This is the relevant link I think:

      http://GreatWhiteCon.info/2015/05/the-new-normal-in-the-arctic/#comment-209391

      Our wager does indeed seem to have been “that CT Area will drop to below 1M km^2 on any day before 2022.”

      I did discuss the possibility of CT disappearing before 2022 in the context of my parallel bet with “Chilly”:

      http://GreatWhiteCon.info/2015/05/the-new-normal-in-the-arctic/#comment-209109

      Do you anticipate spending more time back on the sea ice theme in the coming weeks? I note that the “Slow Transition” thread at the ASIF seems to have burst back into life recently, for example.

  5. Lead author Qinghua Ding has signed on past papers with Willie (oilcan) Soon, $1+ million exxon PR propaganda recipient, for services rendered. Soon-directed Q.D. has been looking for “natural causes” for years… & AGW denier liar whiners found themselves “a new scientist” to tote the AGW denier liar whiner ball. Hope Soon is nicely retired, so exxon can give Q.D., $2 million…. gotta keep up with inflation, ya know.

    1. Qinghua Ding has indeed been listed at the top of the same paper as Willie Soon:

      http://journals.ametsoc.org/doi/abs/10.1175/2008JCLI2353.1

      However correlation doesn’t necessarily equal causation! According to a comment over at Stoat:

      Sometimes we can take guilt-by-association suspicions a little too far. Qinghua and I recently were co-PIs on an NSF proposal and I have no reason to suspect that he is anything but the careful and imaginative large-scale dynamicist that he appears to be.

      As I pointed out over there:

      Surely you’re not suggesting that the likes of Axel Schweiger (of PIOMAS fame) and Eric Steig would somehow allow their strings to be pulled by Big Willie?

  6. Very consequential high internal variation needs a very high climate sensitivity to forcings. Kinda the opposite of what we need. I don’t know why the deniers are cheering… talking about a dumb bunch..

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