Note to media: Enough with the multiple hedges on climate science!

In an otherwise fascinating story on the growing “icebreaker gap” in the rapidly defrosting Arctic Ocean, NYT reporter Andy Revkin writes:

“Even with the increasing summer retreats of sea ice, which many polar scientists say probably are being driven in part by global warming caused by humans, there will always be enough ice in certain parts of the Arctic to require icebreakers.”

I do not view a quadruple-hedged climate impact attribution as acceptable for a major media outlet: “many” and “polar” and “probably” and “in part”!!!!

It isn’t just “many polar scientists” who say this, it is pretty much “the overwhelming majority of climate scientists” — especially because he threw in two more hedges “probably are being driven in part.” Heck, with those two hedges, you could probably just drop “many polar” and say “which scientists say probably are being driven in part by global warming caused by humans.”


Second, “always” is forever, but ice isn’t, especially since on our current greenhouse gas emissions path, we may see more than 5°C global warming this century (see “Is 450 ppm politically possible? Part 0: The alternative is humanity’s self-destruction“). Had Revkin said “there will always be enough ice in certain parts of the Arctic during some parts of the year,” that I think would be something many polar scientists would probably agree with [in part]. But as is now written, I think not.


I think it is a central role of the media to let the public know just how solid the overall scientific understanding of climate science is. I think matters of climate science should have two hedges at the very, very most — and only then if it is a relatively controversial matter and your editor refuses to let you use a single hedge.

I think well-established reporters on climate science, like Revkin, should have at most one hedge, especially for areas that are not especially controversial.

Using this story as an example, if my editor would let me, I’d have written:

Even with the increasing summer retreats of sea ice, which climate scientists say are being driven in large part by global warming caused by humans….

I think the very least that is acceptable would be

Even with the increasing summer retreats of sea ice, which polar scientists say probably are being driven in large part by global warming caused by humans….

Though even there, I think “climate scientists” would be preferable.

I think one could also drop “in part” entirely, since the word “driven” has its own ambiguities. Thus the strongest version could read:

Even with the increasing summer retreats of sea ice, which climate scientists say are being driven by global warming caused by humans….

Yes, that is strong. But how many climate scientists could you find do disagree with that statment? In 10 or 20 years, historians and sciences and even the general public of the scratching their heads at how we could have been so wishy-washy reporting the obvious.

Note to Revkin: Going back to your original phrasing, can you even find three polar scientists who disagree with the claim that “the increasing summer retreats of sea ice … probably are being driven in part by global warming caused by humans”? Not with the words “in part” there. Heck, how many would disagree with the statement if it read “in large part.”

Bottom Line: I’m not certain how the public is going to understand the dire nature of our climate situation in time to avert calamity if the media keeps filling their climate science articles with multiple hedges.

UPDATE: I really do not mean to single out Revkin. He just happens to be the gold standard — the most prolific and high profile climate journalist. That’s why I changed the post headline (though the slug remains unchanged since changing it screws up those with an RSS feed). I have complains about many other major media outlets, see for instance, Dateline NBC: “Whatever the cause … global warming is a reality.

That said, I view part of Revkin’s comment below as outrageous. He writes “hardly any would say there’s sufficient evidence to characterize it as the dominant force up there.” Now the best spin on that remarks is that he is referring just to the explanation for the full extent of the 2007 ice melt. The problem is, his article was about “the increasing summer retreats of sea ice.” That makes his comment simply untrue.


16 Responses to Note to media: Enough with the multiple hedges on climate science!

  1. John Hollenberg says:

    Joe, some of us think there may be certain parts of your article that have some validity, at least when applied to specific areas of the theory that global warming may perhaps be occurring, and might be attributable to human activity :-)

    (hedge mode off)

    Seriously, excellent points!

  2. Andy Revkin says:


    I think you’ve completely missed the boat this time in your chiding about inappropriate media multiple hedges (including mine). These are scientists’ hedges, not mine. They are based on the extraordinary complexity of the Arctic Ocean system. Arctic sea ice is varying there because of dynamics AND thermodynamics on many time scales and driven by all manner of influences — with much of the recent drop due to a big flush of thick old ice many years ago. For that October story, I interviewed two dozen Arctic hands, almost all of whom said there had to be a human element.

    But hardly any would say there’s sufficient evidence to characterize it as the dominant force up there. Marika Holland at NCAR warned that the same variability that caused the remarkable dip in 2007 (and less remarkable one this year) could just as easily throw a wrinkle in the other direction.

    In nearly 25 years of writing on humans and climate, I’ve learned to try to distinguish between the facets that are clear and those that remain uncertain. I think that is serving a greater public service than saying we know everything now only to have, say, the Arctic flicker back into cool, icy mode for awhile.

    So while there are few caveats any more about the basics (as in the IPCC saying that more than half of the global warming since 1950 is “very likely” human caused), when it comes to regions (Arctic particularly), the complexities and uncertainty rise. But don’t take my word for it. Come with me to the sea ice some time, or simply to the University of Alaska, Fairbanks, or an Arcus meeting, and let me introduce you to 20 or 30 scientists working incredibly hard to clarify that Arctic Ocean pixel point in the climate picture.

    Click here for more about what’s up with North Pole sea ice.

    [JR: Andy, I think this is one of those cases where you have let your own abundant knowledge of the Arctic blind you to the obvious. I am very well aware and have previously blogged that there are multiple factors that determine the degree of ice lost any given year — but the literature is clear that even in 2007, global warming played “a large part” (see “What drove the dramatic retreat of arctic sea ice during summer 2007?“).

    But your paragraph was not about the specific details explaining the full extent of the 2007 ice melt. It was about “the increasing summer retreats of sea ice.” Again, to say that MANY POLAR scientists say that is PROBABLY being driven IN PART by global warming caused by humans is to eviscerate everything we know about climate science. I assert in the strongest possible terms that at the very least “many” should have been replaced by “most” and “in part” by “in large part” — the latter of which is not mean “the dominant cause.” Although again I challenge you to name even five polar scientists who do not think human-caused global warming is the dominant cause of “the increasing summer retreats of sea ice.”

    Andy — Four hedges is at least two too many.]

  3. JohnnyRook says:

    Thanks for this post, Joe. Revkin writes interesting things, but he is way too solicitous of denyers. I find his annotation of posts with comments from his readers particularly annoying since he often cites some ridiculous statement with no critical comment of his own.

    Blogging for the future at Climaticide Chronicles.

  4. hapa says:

    i’d faint if he didn’t hedge so. the future is downright offensive.

  5. Paul K says:

    The Arctic ice is little affected by CO2 caused “global warming”. That is the science and to say it isn’t is plain wrong. Let me be clear. The fact that factors other than CO2 warming drive the ice does not in any way refute AGW or diminish the possible feedback. Nor does it exculpate fossil fuel. Rhetoric error #2: absolutism

  6. Mauri Pelto says:

    The hedging in this specific case is truly unnecessary. Their are always several complicating factors that either enhance or dampen the response of a system to climate change, in this case warming. However, it has become clear that it is the warming that is the pump primer for the widespread ice pack thinning. A recent paper under review by Sereze and others emphasizes this point. They have identified an amplification of temperature due to reduced sea ice in the Arctic. As a reviewer of this paper, the observations cannot be explained via another mechanism.

  7. Andy Revkin says:

    I stand by what I said in the story and response above. You have a PhD and understand evidence and statistics and complexity. I’ll send out a query, rather than speaking for the sea-ice community, and post anew at Dot Earth.

    But as a starting point, I’ll propose now — and I’ll change this if they disagree — the names of some leading scientists in this field who I’m quite sure would NOT say there is sufficient evidence to conclude that human-caused global warming IS the main cause of increasing summer retreats of sea ice (although they would say there is strong likelihood that it will eventually dominate):

    James Morison, U. of Washington
    Igor Polyakov, U of Alaska, Fairbanks
    Claire Parkinson, NASA Goddard Space Flight Center
    Son Nghiem, NASA Jet Propulsion Laboratory
    Marika Holland, National Center for Atmospheric Research
    John Walsh, U. of Illinois, Urbana-Champaign (and UAF)]

    I stand by the summation of ice experts’ views in my 2007 story:

    More than a dozen experts said in interviews that the extreme summer ice retreat had revealed at least as much about what remains unknown in the Arctic as what is clear. Still, many of those scientists said they were becoming convinced that the system is heading toward a new, more watery state, and that human-caused global warming is playing a significant role.

  8. For the past 20 years the media has faced constant intimidation at the hands of conservatives. Every time the media says something true but with which conservatives disagree conservatives respond by claiming the media is biased towards liberalism. Since the media is full of people who are easily intimidated by claims of bias and prejudice this kind of intimidation works. As a result we find any statement conservatives might find upsetting hedged and qualified. Since conservatives find the idea of global warming upsetting we find it hedged and qualified. After all all those scientists who consider global warming a proven fact can,and indeed are, dismissed by conservatives as liberals. And the people who work in the media are too politically correct to allow themselves to be labeled as prejudiced towards liberalism. They like to think of themselves as being fair and balanced even when that means treating truth and nonsense as equal.

  9. paulm says:

    The media has such an essential role to play in this saga, but if what Revkin says is half true and we have climate scientist (well respected or not) still hedging the facts and making things unclear – then what else can we expect.

    You would expect, at this stage, that these professionals have seen past their bi-spectacles what dangers lie ahead for everyone and would be making a decent effort to alert us to the dire situation.

    They may be our heroes in pointing out the possibility of future climate change, but at the same time traitors to wo/man-kind (and nature) for not having the guts to take the heat in emphasizing the stark reality & dire consequences – not playing a decisive part in influencing our direction to solutions & salvation.

    Joe why don’t you start a guest blog inviting a series of eminent climate scientist (and qualified others) to air their views here. Giving them the opportunity to blow their trumpet and us to hear it straight from the horses (polar bears) mouth?

  10. rpauli says:

    The very structure of US news media enables an anti AGW bias. Paid advertising is the life blood of US mass media – print and broadcast. And carbon based industries are a strong component. No news organization would last long in biting the hand that feeds it – the hedge is an understandable plea for mercy before shooting the messenger.

    One may note that the BBC often has stronger language on these issues. And papers like the Guardian do not seem to have many car and fuel advertising.

  11. rpauli is correct. The problem is made worse by writers and editors who are sensitive about being called prejudiced by supporters of those same carbon based industries. Calling those writers and editors insensitive is exactly what they do when their anti-global warming nonsense is ignored by those writers and editors simply because it is nonsense. So writers and editors in the media are careful to treat anti-global warming nonsense with respect.

  12. Petro says:

    Andy, you should remove Marika Holland from your list. She is the senior author in the paper Mauri referred in his comment.

  13. When I was a boy, we were taught that each generation had responsibilities to assume and duties to perform with regard to the acknowledgement and acceptance of the challenges that are present at that time, so that the next generation can have a chance at a better life. Under no circumstances, would it be correct to pose as willfully blind, hysterically deaf or electively mute in the face of any challenge, as many too many in my not-so-great generation are doing in these days.

    What has happened to the misguided leaders of my generation? So many in the elder generation have determined to let the looming challenges in our time fall into the laps of our children. At least to me, today’s leaders show an astonishing unwillingness to examine the prospects of a good life for those who directly follow us, let alone coming generations.

    After my single, not-so-great generation finishes the `missions’ (ie, fools’ errands) the leading, self-proclaimed “masters of the universe” among us have set before the human community, what resources will be left for our children to consume; how many more people will have to share what remains of the dissipated and degraded resources; where will they find clean air to breathe, clean water to drink? I shudder when thinking about what our children might say about what we have done so poorly and failed to do so spectacularly, all for sake of selfishly fulfilling our insatiable desires for endless material possessions and freedom without responsibility…..come what may for the children, coming generations, global biodiversity, the environment and Earth’s body.

    How could one generation go so wrong? Here are some of the ways.

    First, the leaders in my generation of elders wish to live without having to accept limits to growth of seemingly endless economic globalization, of increasing per capita consumption and skyrocketing human population numbers; our desires are evidently insatiable. We choose to believe anything that is politically convenient, economically expedient and socially agreeable; our way of life is not negotiable. We dare anyone to question our values or behaviors.

    We religiously promote our widely shared and consensually-validated fantasies of `real’ endless economic growth and soon to be unsustainable overconsumption, overproduction and overpopulation activities, and in so doing deny that Earth has limited resources and frangible ecosystems upon which the survival of life as we know it depends.

    Second, my not-so-great generation appears to be doing a disservice to everything and everyone but ourselves. We are the “what’s in it for me?” generation. We demonstrate precious little regard for the maintenance of the integrity of Earth; shallow willingness to actually protect the environment from crippling degradation; lack of serious consideration for the preservation of biodiversity, wilderness, and a good enough future for our children and coming generations; and no appreciation of the vital understanding that humans are no more or less than magnificent living beings with “feet of clay.”

    Perhaps we live in unsustainable ways in our planetary home; but we are proud of it nonetheless. Certainly, we will “have our cake and eat it, too.” We will own fleets of cars, fly around in thousands of private jets, live in McMansions, exchange secret handshakes, frequent exclusive clubs and distant hideouts, and risk nothing of value to us. We will live long, large and free. Please do not bother us with the problems of the world. We choose not to hear, see or speak of them. We are the economic powerbrokers, their bought-and-paid-for politicians and the many minions in the mass media. We hold much of the world’s wealth and the extraordinary power great wealth purchases. If left to our own devices, we will continue in the exercise of our `inalienable rights’ to outrageously consume Earth’s limited resources; to recklessly expand economic globalization unto every corner of our natural world and, guess what, beyond; and to carelessly consent to the unbridled global growth of human numbers so that where there are now 6+ billion people, by 2050 we will have 9+ billion members of the human community and, guess what, even more people, perhaps billions more in the distant future, if that is what we desire.

    We are the reigning, self-proclaimed masters of the universe. We enjoy freedom and living without limits; of course, we adamantly eschew any talk of the personal responsibilities that come with the exercise of personal freedoms or any discussion of the existence of biophysical limitations of any kind.

    We deny the existence of human limits and Earth’s limitations.

    Please understand that we do not want anyone presenting us with scientific evidence that we could be living unsustainably in an artificially designed, temporary world of our own making….a manmade world filling up with gigantic enterprises, virtual mountains of material possessions, and boundless amounts of filthy lucre.

    Third, most of our top rank experts appear not to have found adequate ways of communicating to the family of humanity what people somehow need to hear, see and understand: the rapacious dissipation of Earth’s limited resources, the relentless degradation of the planet’s environment, and the approaching destruction of the Earth as a fit place for human habitation by the human species, when taken together, appear to be proceeding at breakneck speed toward the precipitation of a catastrophic ecological wreckage of some sort unless, of course, the world’s colossal, ever expanding, artificially designed, manmade global political economy continues to speed headlong toward the monolithic `wall’ called “unsustainability” at which point the runaway economy crashes before Earth’s ecology is collapsed.

    Who knows, perhaps we can realistically and hopefully hold onto the expectation that behavioral changes in the direction of sustainable production, per human consumption, and propagation are in the offing…..changes that save both the economy and the Creation.

    Steven Earl Salmony
    AWAREness Campaign on The Human Population, est. 2001

  14. David Lewis says:

    Andy Revkin promised to send out

    “a query, rather than speaking for the sea-ice community, and post anew at Dot Earth. ” to see if he is correct about his summary of the science. So far, this hasn’t appeared. Now that just about two weeks have gone by, I posted a comment saying I was wondering where the result of this communication was.

    What follows is my post from Dot Earth. Andy had posted a photo of a polar bear in the Arctic ocean water with no ice anywhere in the photo with a subhead “swimming polar bears, the ultimate climate icon?”, so I took that opportunity to post this:

    This particular polar bear is the ultimate icon of: “the increasing summer retreats of sea ice, which many polar scientists say probably are being driven in part by global warming caused by humans”.

    (quote from Andy Revkin, August 16, 2008, NYTimes article, “A Push to Increase Icebreakers in the Arctic”)

    The bear was originally hired to pose for a photo as a symbol of the clearest signal yet seen that the stability of the Earth’s climate had already been destroyed, for the use of some planet hugging campaigner who is frantically trying to wake up civilization to its peril, but when Andy’s article in the New York Times hit the streets on what’s left of the ice up north the project was almost cancelled.

    The bear was informed he needed to symbolize a qualified and wishy washy semi problem people weren’t even unifed was anything more than some ocean currents and a big wind hitting a starving and recently divorced bear who needed to stop blaming Western Civilization for his problems when what he needed was a life skills upgrade. This just depressed the bear and he jumped into the water, some say, bent on suicide. The crew got this shot of him treading water going nowhere while he was being blasted with prop wash from the camera helicopter, and they instantly knew they had what they wanted: an iconic photo that would rank right up there in the “as good as any” category with all those other great photos recording events as the death of civilization proceeds.

    Funds to put him out of his misery are indeed pouring in, as shipping magnates and oil companies rush to build whatever it will take to turn the Arctic into something resembling the Gulf of Mexico and the Singapore Straits now that some mysterious inexplicable never seen before but most probably not dominated at this time by human induced global warming mix of forces completely transforms the Arctic and the rest of the planet by causing the reflective summer ice that since the last ice age has covered the heat absorbing ocean there to disappear. This process will continue to alter the planetary and regional albedo as it proceeds which will increase the forces threatening to distintegrate the Greenland ice sheet, which has profound implications for regional climate on the European continent, global sea level and global climate.

    I mean, if any of this is happening at all. Maybe that’s a fake polar “bear” in a Hollywood back lot pool with a big fan blowing down to simulate a “helicopter”, and all the ice is still up there in the north. As George Bush prepared to leave Japan after the G8 recently he thought he was away from the press so “he punched the air while grinning widely, as the rest of those present including Gordon Brown and Nicolas Sarkozy looked on in shock” and said “Goodbye from the world’s biggest polluter” * Obviously, the science is not clear so we must all pretend that Bush, the oil and coal industries that back him, and the still sizable percentage of the American people who back his party, are going to be convinced when that next fact comes in.

    I was wondering where the communications Andy said he was going to ask for from the “sea ice community” about whatever he was going to ask them to comment on in reference to his one half sentence summary of what they thought, quoted above, were.

    The bear pointed out that maybe the polar scientists with their zest to find an accurate and precise explanation for this dramatic change in their region of interest weren’t the ones to go to for a summary of the significance of what is going on. He said he’d be more interested in what climate scientists with a more global perspective had to say, but he was too busy treading water going nowhere to email his thoughts in.

    ( *10 July 2008 article “President George Bush: ‘Goodbye from the world’s biggest polluter’)

  15. Cynthia says:

    Revkin writes really well. Unfortunately, most of what he writes is bullstuff! I study global warming religiously and what he says is a complete contradiction to what the majority of climate scientists say. (and most other scientists as well!@)

    It makes me sad when I read stuff which surreptiously misleads… reminds me of the issue of racial prejudice: when someone is outright prejudice, it’s easy to see and people condemn it. But when someone PRETENDS that they’re not prejudice and they really are, it’s a lot more insidious. The same goes for the climate change issue. It’s evil to pretend you’re on one side when all along you’re on the other side.

  16. Cynthia says:

    People can say what they want about it; I go (mainly) by what Jim Hansen says. He’s the world’s most respected climatologist, head of NASA for 30 years, and so far, he’s been correct on all his predictions (except when he’s been too conservative). He certainly says that the arctic melt is caused by humans and advocates zero emissions NOW.