At Issue: Role of Arctic Sea Ice Melt in Mid-Latitude Cold Extremes

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A ‘real’ and legitimate settling of differences is under way in the science community far different from, and far more worthwhile than, the usual talk-show ‘battling pundits’ variety.

Don’t look now, but there’s a sensible, and perhaps even meaningful and healthy, debate among real climate scientists over a hot issue: It all involves research on the rapidly melting Arctic sea ice and the kinds of blustery weather that has made the winter of 2014 so miserable for mid-latitude areas across much of the U.S.

It’s not one of those made-for-cable “talking heads” yell-a-thons that climate scientists so rightly deplore. Nor does it follow the all-too-common mass media practice of pitting the flame-thrower on the far left and the wacko on the far right against each other. This one, warts and all, shows how serious science can work at resolving differences of interpretation and significance.

News Analysis

But for some the concerns also involve whether this back-and-forth is simply commanding too much of the media and public awareness bandwidth, in effect becoming what National Academy of Sciences Member John Michael (Mike) Wallace of the University of Washington calls “a stumbling block in our public discourse on human induced climate change.”

At Issue: More Global Warming in the Arctic = More Mid-Latitude Chilly Days?

It all goes back to a now often-cited but much-debated hypothesis that Rutgers University scientist Jennifer Francis and University of Wisconsin scientist Stephen Vavrus detailed in Geophysical Research Letters in 2012. They hypothesized that in causing rapid melting of the Arctic sea ice, global warming would bring about changes in the flow of the jet stream, slowing-down its pace and leading it to reach further southward … and therefore carrying colder temperatures further south than usual and for longer periods.

As they wrote then, warming in high northern latitudes, the Arctic, causes “associated weather patterns in mid-latitudes to be more persistent, which may lead to an increased probability of extreme weather events that result from prolonged conditions, such as drought flooding, cold spells and heat waves.” They wrote that their “observational analysis … provides evidence” to support the theory that warming in the Arctic exceeding that at mid-latitudes “may cause more persistent weather patterns in mid-latitudes that can lead to extreme weather.” They concluded that further research “will elucidate the types, locations, timing, and character of the weather changes.”

A subsequent research paper, with Francis one of four authors, suggested that “winter atmospheric circulation at high northern latitudes associated with Arctic sea ice loss, especially in the winter, favors the occurrence of cold winter extremes at middle latitudes of the northern continents.” In that 2013 paper, Francis and her co-authors noted that “while changes in atmospheric circulation can affect sea ice, sea ice loss can also have an impact on the atmospheric circulation.” They wrote that regression analysis cannot prove connections between sea ice loss and large-scale circulation patterns in the northern hemisphere, but that their research results “provide further evidence of the relationship.”

If ‘Robust’ … More Cold Winter Extremes Ahead

“If the association between Arctic sea ice and cold winter extremes demonstrated in this study is robust,” they concluded, “we would expect to see a continuation and expansion of cold winter extremes as the sea ice cover continues to decline in response to ever-increasing emissions of greenhouse gases.”

All of which has led some in the media and many in the climate “skeptics” camps to a simplistic formulaic conclusion: More greenhouse gases emitted means more global warming, which in turn leads to colder winters in mid-latitude regions. Ergo, more global warming leads to more cold weather in those regions. Which is to say, by their reasoning and as they would have us believe, that scientists think global warming causes everything.

That’s not the case, but the Francis theory has continued to gain momentum in some quarters, including having made her a common presence in a growing number of news stories about the blustery winter temperatures. Francis too has continued to defend the hypothesis, recently saying “There is a lot of pretty tantalizing evidence that our hypothesis seems to be bearing some fruit.” (This quote comes from a well worthwhile “Inquiring Minds” podcast involving Francis and Kevin Trenberth of NCAR, a prominent scientist who is among those challenging her findings.)

Critics:  ‘Interesting, Deserves a Hearing’ , but not ‘Compelling’

But other scientists, including a seemingly growing number of what Wallace calls “grey beard” climatologists, are not so sure. In fact, they find the argument generally unsupported and, as yet at least, clearly unsubstantiated. While supporting “a fair hearing” of the Francis hypothesis as “an interesting idea,” the five scientists argued in a recent letter to Science magazine that “alternative observational analyses and simulations with climate models have not confirmed the hypothesis, and we do not view the theoretical arguments underlying it as compelling.”

Those words come from their “Global Warming and Winter Weather” letter to Science, a letter they initially sent, to no avail, to letters editors at The New York Times and The Washington Post. Signed by Wallace and four other preeminent climate scientists, that letter points blame not only at the hypothesis in the original research paper and the principal author’s speaking out for it, but also at some in the media. Their concern: both have contributed to making the issue “the centerpiece of the public discourse on global warming.”

“Inappropriate and a distraction,” wrote Wallace and his colleagues — Isaac Held of NOAA, David W.J. Thompson of Colorado State University, Kevin Trenberth of NCAR, and John E. Walsh of the University of Alaska, Fairbank.

“Coincidence does not in itself constitute a strong case for causality,” they lectured in their letter. They wrote that the lag time between decreased sea-ice extent in the Arctic and changes in mid-latitude atmospheric circulation patterns later, when loss of sea ice is “much smaller,” needs to be better reconciled with theory. “Harsher winters in future decades are not among the most likely nor the most serious consequences of global warming,” those five scientists concluded. With that comment, the scientists apparently were venting their angst not so much with Francis but rather with Presidential Science Adviser John Holdren’s seeming endorsement of her hypothesis, which Wallace thinks lent the research an undue policy gravitas “as if they [cold winter weather events] were the only impact of global warming.”

Use and Abuse of Francis Research by Advocates and Media

In addition to challenging the Francis hypothesis and research, Wallace seems particularly concerned with how her research is being used — and abused — by partisan interests. That’s an area of agreement between Wallace and Francis.

“I disagree with those who argue that we need to capitalize on recent extreme weather events to raise public awareness of human-induced global warming,” Wallace wrote in a guest commentary at The Washington Post’s Capital Weather Gang blog. He faulted some in the media for not adequately distinguishing between “the broad scientific consensus on climate change,” as expressed, for instance, in IPCC reports, and “various unsubstantiated hypotheses relating to extreme weather events.”

The resulting public confusion, Wallace continued, opens the door “to attack by the apologists for economic growth at all costs. It didn’t take them long to learn that poking fun at the notion that global warming could lead to extreme cold is an effective tactic.”

In making their case against the Francis/Vavrus research findings, the letter writers to Science pointed, among other things, to research published by Colorado State University Professor Elizabeth Barnes in Geophysical Research Letters in 2013. Barnes in that paper found “unsupported by the observations” the Francis hypothesis that amplified polar warming leads to more slow-moving weather patterns and to “blocking episodes” making them last longer. In addition, Barnes pointed to another study suggesting “an artifact of the [Francis] methodology” as the culprit. She concluded that more targeted modeling studies are needed “to quantify the relative importance of polar changes on Atlantic weather.”

More Media Voices Weigh In …

On the heels of publication of the Science letter on February 14, experienced science writers Jason Samenow, in The Washington Post, and Chris Mooney, for Mother Jones and Climate Desk, have explored the ongoing exchanges between Francis and those critical of her study and its conclusions.

Samenow wrote on February 20 for the Post’s closely followed “Capital Weather Gang” blog that “more and more scientists are expressing reservations” about Francis’s hypothesis. He wrote also that “numerous mainstream press outlets have written about the Francis theory uncritically, failing to present countervailing views,” including those of IPCC. He pointed specifically to what he considers to have been flawed coverage by BBC and by NPR.

Samenow commented also that “even the White House’s science advisor, John Holdren, expressed support for the theory with only subtle qualification,” a development clearly unsettling also to Wallace.

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Extreme cold in U.S. in ‘unmistakable decline’…Just try telling that to many who so far in 2014 have suffered one wintry storm after another.

“The truth is that cold extremes are in the midst of unmistakable decline in the U.S.,” Samenow wrote, and he said even those in the winter of 2014 aren’t really so impressive when compared to earlier ones.

In an in-depth piece posted February 21, author and writer Chris Mooney examined many of the points made by Francis and critics of her research, and he referred to “an increasingly epic debate … the biggest debate in climate science” over Francis’s “influential theory.”

Those characterizations may seem unwarranted to some earth scientists, but Mooney wrote that he finds it unsurprising that media interest in the Francis hypothesis had gained her “rapid celebrity.” He wrote that her research “seems to make sense of our mind-boggling weather,” and he said it “isn’t often” that an idea first published in the literature less than two years earlier “is strongly embraced by the President’s science adviser,” Holdren.

Mooney wrote too that the current discussions of Francis’s findings differ from so many others involving “fake, trumped up affairs generated by climate skeptics who aim to sow doubt.” He characterized the current back-and-forth as “real, legitimate, and damn interesting to boot,” with “a massive amount at stake.”

“No wonder, then, that Francis’s ideas have gotten so much media attention,” Mooney wrote. “At a time when all of us are searching for some explanations for mind-boggling winter weather, along comes a scientist who seems to explain it all to us clearly, and also to link it to climate change.”

The Samenow and Mooney reports are far from the first to be written or posted about the flap over the Francis research. The Yale Forum’s “This Is Not Cool” video series has several times featured Francis and her research, and its June 2013 video featured Francis and NCAR’s Trenberth addressing their differences over her findings.

In addition, well-regarded science writer Andrew Freedman, now with mashable.com, had written several insightful pieces on the research brouhaha while with Climate Central in Princeton, N.J.

And in mid-February, former New York Times science correspondent Andy Revkin blogged at the paper’s Dotearth site about the Wallace et al. letter to Science, and reactions to it by Francis and others. The Revkin post provides extensive direct quote claims and counterclaims providing further context on the whole issue.

In an analysis of the Francis et al. research, science writer Fred Pearce, in a February 24 post at Yale E360, concluded that “weird weather is definitely on the agenda, and the jet stream is very likely to be an important part of it.” That, as far as it goes, appears pretty much unarguable, though Wallace says it ignores that policy makers and scientists can have different “agendas,” which he thinks is by and large the case here.

Pearce then addresses the what-if matter: What if Francis is “proven right” about the jet stream’s becoming “stuck” in a particular trajectory, and what if it brings with it strong winds and heavy rains? He wrote that the U.K.’s Met Office “says the Francis scenario ‘raises the possibility that disruption of our usual weather patterns may be how climate change may manifest itself.’ If so, that would indeed unleash the perfect storm,” Pearce concluded.

In End, Will Mass Media Coverage Be A Plus … or a Minus?

None of which, mind you, is likely to greatly allay the concerns of the five scientists and a number of their colleagues who fear the “biggest debate” memes are as yet unwarranted and, again, a distraction, particularly as those may be the impressions left by the large-circulation media outlets.

In the end, some might still maintain that despite the scientists’ legitimate concerns with how some in the media and some advocates have misrepresented Francis and her research, the resulting finger-pointing hardly amounts to climate change’s “biggest” current fuss-up, nor should it. But one way or another, the issue is likely to continue to be thrashed-out among serious scientists in serious peer-reviewed journals and in their professional meetings and exchanges.

The question arises whether that process, and its eventual resolution, will be drowned-out in mass media coverage, and therefore in the public’s and policy-makers’ minds, by the mindless chatter of those more interested in capturing a headline and some personal visibility than in moving forward on evidence-based climate science and challenges.

It will be a pity if the media end up being complicit in that distraction from more serious climate issues … but at this point that might come as a disappointment, but not necessarily as a surprise, to many.

Bud Ward

Bud Ward is editor of Yale Climate Connections. (E-mail: bud@yaleclimateconnections.org).
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4 Responses to At Issue: Role of Arctic Sea Ice Melt in Mid-Latitude Cold Extremes

  1. Bob Bingham says:

    Jennifer Francis makes a very good case for her presentation and if she is right it is the fastest acting part of climate change. No waiting 100 years for half a meter of sea level rise or thirty years for the heat to come back out of the oceans this appears to be quick.
    The disagreement seems to be about the speed and size of the reaction as it has manifested itself in only the last seven years which is far too short a period for proper monitoring. The southern hemisphere is completely different and our jet stream seems OK. http://www.climateoutcome.kiwi.nz/ice-melt.html

  2. A well-written review of Francis vs other climate scientists vs media. Kudos for clarity. Not much is said, however, about moisture distribution associated with these recent gyrations in the jet stream. I suppose most of the models would include moisture as well as heat, but I know little about modeling such a complex set of factors, and less about their predictive values. The popular media are well known for their abilities to confuse issues, now even more so with so many outlets and so many poorly understood perceptions. Thanks for helping us to sort this out.

  3. Joe Witte says:

    Media norms of what is news depend on a number of items ( news hooks): 1. Conflict/drama 2. Personification 3. Novelty or 4. Big events (Kennedy’s death, Mt. St. Helens ). The drama of recent severe winter weather has makes it natural and easy for media to use that news hook. The supposed novelty of the jet stream patterns might or might not answer answer the question of why but gives the media something quick to blame. The majority of the popular media will not spend much more time to explain complex teleconnections. Thank goodness for those that do. People are looking for a quick and easy heuristic to help them make meaning of what they see happening in their world, a kinky jet stream fills that psychological need. News editors and headline writers look for a sound bite that gets attention. People are cognitive misers about science: don’t make it too complicated, ‘I have so many other worries’. The visual rhetoric of the jet stream is persuasive messaging. One has to wonder why didn’t a similar jet pattern happen last winter after the late summer of record open Arctic waters? And how does that teleconnection extend to 3-4 months later after the Arctic has been completely covered, cutting off ocean heat and moisture release? Extreme weather is a news ratings winner and now competes with ‘if it bleeds it leads’.
    The temptation for media for screaming headlines is just too great.

  4. Paul Quigg says:

    To this scientific layman, the extreme Arctic Amplification would seem to be a logical place for evidence of warming to first show itself. This hypothesis will or will not stand the test of time.
    I see more rational discourse entering this climate change debate. It’s slow and we still have the fringe wackos. The inertia in our climate is frustrating to our impatient minds. A rational discussion of this “new” hypothesis is way down the road.