Evidence Builds That Scientists Underplay Climate Impacts

Far from being “alarmist,” predictions from climate scientists in many cases are proving to be more conservative than observed climate-induced impacts.

The observed rate of Arctic ice loss exceeds the projections of all IPCC climate models — by NSIDC scientist Julienne Stroeve updated through 2011 (via Climate Crocks, click to enlarge).

By Douglas Fischer, Daily Climate editor, in a repost

The warnings were dire: 188 predictions showing that climate-induced changes to the environment would put 7 percent of all plant and animal species on the globe – one out of every 14 critters – at risk of extinction.

Predictions like these have earned climate scientists the obloquy from critics for being “alarmist” – dismissed for using inflated descriptions of doom and destruction to push for action, more grant money or a global government.

But as the impacts of climate change become apparent, many predictions are proving to underplay the actual impacts. Reality, in many instances, is proving to be far worse than most scientists expected.

“We’re seeing mounting evidence now that the scientific community, rather than overstating the claim or being alarmist, is the opposite,” said Naomi Oreskes, a science historian with the University of California, San Diego. “Scientists have been quite conservative … in a lot of important and different areas.”

A decade ago scientists predicted the Arctic wouldn’t be ice-free in summer until 2100. But the extent of summer ice in the North has rapidly shrunk and today covers 70 percent of the area it did in 1979. Now some scientists think the Arctic could be naught but open water within 25 years.

In August, a team lead by University of York researcher Chris Thomas published a study showing that plants and animals are moving to higher elevations twice as fast as predicted in response to rising temperatures. They’re migrating north three times faster than expected, they found

As for extinctions, earlier this year two scientists at the University of Exeter paired predicted versus observed annihilation rates. The real-world rates are more than double what the best computer modeling showed: While the studies, on average, warned of a 7 percent extinction rate, field observations suggested the rate was closer to 15 percent.

Oreskes has spent a career studying climate science. She finds ample evidence that climate scientists are indeed biased – just not in the way portrayed by politicians such as Texas Gov. Rick Perry, who claimed scientists paint a bleak picture to secure more research funding.

In reality, Oreskes said, scientists skew their results away from worst-case, doomsday scenarios. “Many people in the scientific community have felt that it’s important to be conservative – that it protects your credibility,” she said. “There’s a low-end bias. It has led scientists to understate, rather than overstate, the impacts.”

Media’s fault, too

Not all scientists agree that they and their colleagues have deliberately downplayed impacts, of course.

But other scholars have noted the misperception – and argued the fault lies not just with scientists, but also with journalists reporting those findings.

In a notable 2010 study, the late William Freudenberg, a University of California, Santa Barbara, researcher who studied science and the media, found that new scientific findings are more than 20 times likely to show that global climate disruption is “worse than previously expected” rather than “not as bad as previously expected.”

He drew two conclusions from the assessment, one for scientists and one for journalists:

Scientists should be more skeptical toward supposed “good news” on global warming. And reporters, he warned, “need to learn that, if they wish to discuss ‘both sides’ of the climate issue, the scientifically legitimate ‘other side’ is that, if anything, global climate disruption is likely to be significantly worse than has been suggested in scientific consensus estimates to date.”

Inherent challenges

Of course, the science of climate modeling itself could be inherently biased. Predicting the future impact of emissions remains a difficult task, despite advances in the field over recent decades. Disparate elements can interact in surprising and additive ways that belie scientists’ best assumptions.

That may be the case with the discrepancy between predicted and observed extinction rates, said Ilya Maclean, a researcher at the University of Exeter and lead author of the study, published in July in the journal Proceedings of the National Academy of Sciences.

Many studies he examined tie predicted extinction rates to just one factor – rising temperatures, say, or loss of habitat due to sea-level rise. But a changing climate can impact habitats and species in diverse and unexpected ways, he said.

“That’s not to say there are always additive effects,” Maclean said. “But that might be one of the reasons why predictions tend to be quite conservative.”

As for the notion that scientists are – unconsciously or not – underplaying impacts, the charge has a ring of truth for Maclean.

Academics are a cautious lot, generally wary of being seen as making “alarmist” predictions, he said. The peer-review process tends to discourage bold or aggressive interpretations of data.

It’s a trend he recognizes even in his work: Maclean and his co-author, Robert Wilson, also a researcher at the University of Exeter, were careful to exclude any studies and factors they could not definitively link to climate change. That meant excluding a “fairly large” body of work from their analysis, he said.

Their standards, he acknowledges, were probably a little too conservative. But the main point of the paper wasn’t to highlight the gap between predictions and observations, he said. They simply wished to show the predictions were reasonable, not alarmist.

In an interview, Maclean was willing to “go beyond the message of the paper” and flatly state that the extinction predictions are too conservative.

But, he added, “I can’t say it definitively.”

By Douglas Fischer, Daily Climate editor, in a repost

Related Post:

40 Responses to Evidence Builds That Scientists Underplay Climate Impacts

  1. prokaryotes says:

    Voiced from Ground Zero:

    Climate change spawns incredible droughts

    Plants and animals are fast getting depleted because global temperatures are getting warmer with water sources drying up, African Union Commission (AUC) deputy chair Erastus Mwencha said here yesterday.

    He warned the development could have profound implications for food production in future.

    Mwencha, who spoke during the opening of the first Climate Change and Development for Africa Conference said the continent was under threat from the effects of climate change.

    “These extreme climate change events are projected to most likely continue with increasing frequencies and severity in impacts. All of Africa is very likely to warm during this century, a warming that is very likely to be larger than the global, annual mean warming and in all seasons. The worst-case scenarios . . . are that food crops and animals will shrink enough to have real implications for food security,” he said.

  2. Joan Savage says:

    Rather than call scientists “conservative,” I think a fairer limitation to scientific projections is how outcome probability is usually estimated only from measured factors. That leaves out a residue of unknowns in a system.

    Some models do not emphasize time-series combinations that can ramp up the consequences, even though real ecosystems do have time-sensitive junctures. Work on stochastic patterns and other areas of statistics may help with this.

    The ability to model complex environmental systems is still in development. It’s amazing to even have what we do have.

    Perhaps someone might sponsor a Freudenberg Memorial Debate among climate scientists and climate policy analysts, following his insight.

    “Reporters need to learn that, if they wish to discuss “both sides” of the climate issue, the scientifically legitimate “other side” is that, if anything, global climate disruption is likely to be significantly worse than has been suggested in scientific consensus estimates to date.”

    On one side could be Joe Romm and the military climate theorists who have a serious list of serious consequences, and on the other, who? ..the IPCC?

  3. prokaryotes says:

    In a world where scientists are censored, with ill intentions investigated, receive death threats and have to fight a multi million dollar denial machine, you have the perfect setup for a catastrophe and the possibilities for the worst case scenarios becoming true.

    If we do not act today, it will be soon to late for the human race. We approach a territory where we have the chance to risk the survival of the species.

    Emissions today are above the worst case emission scenarios of the IPCC.

  4. Wes Rolley says:

    With all of the focus on how youth will change the world, it is great to see that the old soldiers in this battle are still carrying on the fight. Pete McCloskey: Oil and Smokes.

  5. Z S says:

    I love the chart at the top of the post, but I think it’s important to clearly lay out the significance (I mean that in both the figurative and statistical sense) of the Mean falling outside of the Standard Deviation. A lot of people without a statistical background might interpret the chart to merely mean that sea ice extent is a little bit below the range of some estimates.

  6. Joe Romm says:


    I threw this chart into this post since it was the best chart I knew of for it. But I had been meaning to do a separate post around it.

    It is obviously a huge deal that every single model was too optimistic.

  7. lasmog says:

    Still more evidence that we are collectively sleep walking towards the abyss. Even our scientists are bending over backwards to not sound alarmist when we are clearly in a situation that calls for alarm. The time for being polite is over, someone better start screaming fire.

  8. Mike Roddy says:

    I look forward to your followup here, Joe, as well as your ideas on getting the message out. Climate scientists have long told me that they are more pessimistic than what they say in public, but now the data is becoming pretty obvious. IPCC hedged its conservative but still frightening trajectory by making assumptions about emissions reductions that have turned out to be dreams.

    It will be interesting to see IPCC V early drafts. Maybe more aggressive scientific leadership will see to it that world leaders get the message, which should include a lot more feedback scenarios in the next version. When the oil companies attack the document through their paid journalists and politicians, IPCC scientists need to become pugnacious, instead of throwing up their hands, signing group policy letters, and returning to the lab. It’s much too late for that.

    “Alarmist” is just another clever and meaningless term laid on the scientists by the oil and coal PR firms. Somehow this whole notion has made too many scientists afraid to speak up. They should have noticed by now that journalists have abdicated. We need a better word along with fresh ideas.

  9. Dennis Tomlinson says:

    I recently finished Michael Mann’s book “Dire Predictions: Understanding Global Warming”. One chapter is dedicated to how bleak the future looks, which Mann prefaces with one of James Lovelock’s quotes about a drastically downsized population in a dystopian future. Mann includes a short bio in which he says that Lovelock has a history conceiving ideas which initially are outside the mainstream, but ultimately become accepted science. Are we now beginning to fear that Lovelock is once again right?

  10. Gail Zawacki says:

    The other thing that most climate scientists do not factor into the impacts of extreme weather and warming on biota is pollution, even though this appears to be, at least in the short term, more damaging.

    I had to laugh at this quote in a story in the NYT about solid research indicating species are literally shrinking:

    “Yet the research community over all has been less than enthusiastic about embracing the idea. ‘The scientific community is really hesitant to publish things that are potentially inflammatory,’ said David Bickford, an evolutionary ecologist at the University of Singapore and a co-author of the paper. ‘People don’t want to think that this is a new reality, everything shrinking.’”

    expanded upon here:

  11. Jeff Huggins says:

    Scientists Under-convey the Gravity of Climate Change and Its Likely and Possible Impacts

    If it’s correct that “scientists underplay climate impacts”, that’s a problem, but it’s not the largest problem with what the scientific community is and isn’t doing.


    Scientists should understand that we humans are still social primates. I don’t say this to demean us, nor to demean other social primates, who (after all) aren’t messing up the whole world. Instead, I say it to remind the scientific community about how humans receive information, from where we take our clues, and how we assess what to consider REALLY, REALLY important.

    No social primates — other than humans — ever wrote a letter to their hierarchy upon realizing that the group faced a threat and had better begin to do something about it, soon. Letters don’t convey sufficient gravity and urgency, if they’re the only or even main means of communication. Nor do scholarly articles. Nor do invited speeches. Nor do seminars.

    Scientists, and the scientific community, are UNDER-CONVEYING the GRAVITY of climate change, by their relative calmness and apparent inaction. They should be hooting, hollering, and insisting by now. Period! They should be speaking out, visibly and physically and en masse. Period. Aren’t the climate scientists talking to the evolutionary scientists, the good sociologists, the good psychologists, and indeed the primatologists, and so forth: the best of the scientists who can actually inform them about how humans perceive the words and actions (or inactions!) of their fellow humans, and about what it takes to help people to understand that something really serious is amiss? The scientific community is acting as though it knows a lot about the climate (as it does) but hardly anything about human psychology and communication — and by ‘communication’, I don’t mean mainly words; I mean Communication that actually Communicates!

    No doubt many scientists will think that they’ll lose “credibility” if they get active to the degree that the situation warrants. Phooey! The only way for scientists to RETAIN credibility is for them to be both honest AND active, and I mean ACTIVE.

    Do we not find it odd — and deeply unwise — that our view of science encourages science and scientists to uncover everything possible about the workings of nature — to open any and every “Pandora’s Box” — to uncover nature’s most powerful dynamics and make them available to anyone, for the making of atom bombs, genetically engineered organisms, chemical compounds that nature cannot healthfully digest, and etc., AND YET that scientists cannot GET DEMONSTRABLY COMMUNICATIVE to whatever degree is necessary to convey to society that they DO understand that we DO INDEED have a problem? Science is a wonderful tool for discovery, but that’s only half of the equation; because of what we believe scientists shouldn’t get involved in (i.e., Communicating effectively to a degree that’s necessary to actually succeed in conveying understanding), in combination with what scientists are encouraged and allowed to do (i.e., open any Pandora’s Box that human curiosity and cleverness can discover), we are in effect turning science into an instrument of destruction and risk. These facts are as plain as the noses on our faces. They are much more plain than our understanding of the climate. So why don’t we act. We are like deer in the headlights.

    I admire science, and I consider myself a scientist at heart. (I was a Chem Eng from U.C. Berkeley and, early in my career, worked in research for Chevron and also for Eastman Kodak.) But the scientific community had better start speaking up — Communicating with a capital C. There should be more scientists camped out around the White House, right at this very moment, than there are Occupy Wall Streeters demonstrating (rightly so) near Wall Street. I’m not joking. The scientific community has known about the climate change problem for years and years. With understanding comes responsibility. There is NO valid “professional ethic” that trumps and surpasses the general and deep human ethic to protect life. Period.

    Scientists, back up your science, articles, and letters with ACTION that demonstrates the gravity of the matter. If you do something in the San Francisco Bay Area, I’ll join you.

    Be Well,


  12. Rabid Doomsayer says:

    I am glad I am not a climate scientist.

    Realizing a trend is not linear is not the same as proving a quadratic trend is a better fit. Knowing that assuming all carbon from the permamelt will be CO2 is too conservative is not the same as justifying a quantitative methane content.

    We do not on the whole understand scientific uncertainty, instead we discount their confidence intervals as we would Uncle Fred’s “dead cert” on the race track.

    Balancing sources one could be forgiven for assuming climate change will not be serious. Yet if we open our eyes we should be able to see that it is already serious.

    The one parameter scientists have consistently been far too conservative on is the utter stupidity of mankind. Foolishly they assumed we had more collective intelligence than pond scum.

    Says me, yet I know I am making decisions by default that I will regret. Really I should move now while it is a financial possibility, yet here I stay.

  13. dick smith says:

    It’s important to make the case that the IPCC predictions have been, if anything, too conservative.

    But, there is an even bigger take-away point–the real punch line.

    “THIS TIME IS DIFFERENT.” What’s happening with the subsequent DATA today is just the opposite of what happened in the 1970’s with Ehrlich’s predictions of resource scarcity and famine. After the 1970’s alarms, the subsequent data quickly showed that his predictions overestimated the speed. This time subseqent data show just the opposite.

    Journalists and politicians need to understand that THIS TIME the data is doing something very different than what they saw in the 1970’s and ’80s. Don’t leave out the punch line–this is very different than the 1970’s.

  14. Brian R Smith says:

    Fromm Gwynne Dyer’s excellent book (2010 edition) Climate Wars, The Fight For Survival As The World Warms (p91):

    “For the 2007 [IPCC] report, the latest publication date for scientific papers to be included among those considered in the IPCC process was the end of 2005. But the data being analysed in those papers are generally a good deal older than that, for two reasons. One is the publication process itself.”

    (He goes on to describe the year or more long track of the peer-review process once a paper is submitted to a journal and goes out for review before publication.) Then,

    “The other problem is that the data are by definition older than the paper. The data series that constitute the foundation of a given paper will normally end some number of months, or even years, before it is written & submitted for publication. It takes time to analyse the data& draw conclusions, and the best scientists are very busy people. The net result is that most of data that went into the scientific papers that formed the basis for the IPSS’s 2007 report actually refer to 2002 or earlier. In 2010 we are working with predictions that essentially take little notice of the evidence of the last eight years.”

    So i am wondering how the Lag Factor will manifest in the IPCC V Report, and how it may affect the usefulness of the Report as a true policy indicator. Will it be up to Joe to explain, again, that we are in seriously deeper waters than the estimates of the already outdated “new” Report when it finally arrives in 2013/2014?

    Or will the climate science 99% go public in a major way, as Jeff #8 here suggests & I urgently second. We need them now. We will need them when it’s time to explain that IPCC V is not the whole story on the major feedbacks.

  15. Merrelyn Emery says:

    Yes Dennis, because Lovelock works with systems, ME

  16. Merrelyn Emery says:

    Yes Dennis, because Lovelock works with systems, ME

  17. Colorado Bob says:

    Speaking of projections, we missed this one as well. The cost of these events, and just how fast these costs are coming at us. Tonight’s example :

    Hundreds of factories have been swamped, and economic analysts say the floods already have reduced projections for economic growth in 2011 to 2.5 percent, down from 4.4 percent, and could inflict about $6 billion in damage — an amount that could double if floods swamp Bangkok.

  18. Colorado Bob says:


  19. prokaryotes says:

    Precisely, we have to sound the alarm.

  20. David B. Benson says:

    One uses the models and statistical tools currently at one’s disposal together with the all-too-short records plau what the proxies can add. Climatology is distinctly difficult, made harder by the pressing needs for definitive answers (which are rarely forthcoming, at least so far).

    I opine that climatologists have little choice but to report a statistical range for a forecast or projection. Those who then translate the results into risk factors and economic, etc., prognostications perhaps need to more heavily weight the more damaging side. I’d llok to actuaries for adivce as they need to do something similar in order to set insurance rates.

    But don’t blaim the climatologists for failing to have studied actuarial science; climatology is difficult enough as it is.

  21. Yes, scientists are reluctant to footnote their work with “This is a lower bound of unknown quality.”

  22. mdbrock says:

    I was glad to at least hear that the animals were getting smaller. It makes me feel better camping out in grizzly country. The big ones really make me nervous.

  23. Paul Magnus says:

    There are many reputable scientist that are streaming, They have been label alarmist or if too prominent just ignored.

    The rate of change of forcing is closer to an asteroid strike than anything before.

    What does that mean.. Even if we do our best now it’s merly shuffling deck chairs around on deck.

    What we must hope for is that we avert anhialation or even the death of our beloved planet of life. Gaia.

  24. David B. Benson says:

    Stationarity Is Dead: Whither Water Management?
    seems to me to be a fine example of pointing out some consequences of global warming without (at least obviously) understating the consequences.

  25. Lewis Cleverdon says:

    Jeff – well said, but it seems to me that you are over generous in writing:

    “The scientific community has known about the climate change problem for years and years. With understanding comes responsibility.”

    Make that: “has known about the climate change problem for over four and a half generations (of 25 years). With understanding came responsibility, which has been neglected.”

    During all that time, there has been near-zero audible criticism by scientists of the myriad scientists who have enabled and incentivised the agribusiness, deforestation and fossil fuel combustion causing our predicament. That is taking professional solidarity well beyond the threshold of complicity by silence.

    While some have focussed on publishing critical data series, such as the hockey stick, and others have spoken out staunchly of the hazards of political and commercial policy, they have endured vilification and persecution as a result – with little in the way of mass-petitions of support from the scientific community – and some, such as the late great Dr Schneider actually died without hearing a smidgen of defence by either his president or the NAS or the AAAS.

    From this perspective it can be argued that since Arrhenius’s paper in 1896, science has generally become an increasingly amoral activity rather than an exploration for the wellbeing of humanity, with the careers of many of those in relatively few select fields forming the exception that proves the rule.

    Perhaps the greatest failing of what passes for a scientific education is that it provides students with potentially immense powers for good or ill, and yet sets no requirement whatsoever for a parallel education in ethics for each level of degree achieved.

    I suggest we need something of a scientific revolution where all science students (not just medical doctors) must by their study of ethics earn the right to take something akin to the hippocratic oath as the guiding principle of their careers.

    Without this, we’ve been launching unguided missiles of increasing potency for the profit of political and commercial elites, not humanity. Just the damage done by the many psychologists employed by the patently amoral advertizing industry may take generations to heal.



  26. Colorado Bob says:

    Notes from the TX State Climatologist
    by: Chris Searles

    I got to hear John Neilsen-Gammon (link:… , the State of Texas’s Climatologist (link: , speak about the “Basic mechanisms of the 2011 TX Drought” and our “Outlook for the future: short & long terms” last Friday. His presentation, loosely, was titled, “Texas Drought: Why You Should Get Used to It.” His closing point, “If you want a better forecast, check back in five years.”

    So, with that in mind, here are some highlight notes from the presentation.

  27. Colorado Bob says:

    CLEVELAND, Ohio — In 2007, a respected U.S. climate scientist predicted that Ohio’s weather would become “more like Arkansas” over the next century.

    Here in 2011, the future seems like now.

    Cleveland’s near-record year for precipitation — more than 52 inches and counting — has already pushed the city to rival typically rain-soaked communities such as Little Rock, which gets an average of 49 inches of precipitation each year.

  28. Colorado Bob says:

    So are the heavy rains of 2011 more local evidence of global climate changes? A Plain Dealer 2009 study of rainfall records seemed to corroborate other recent studies showing that annual rainfall – especially bolstered by heavy, high-impact storms – was on the increase in the northern part of the state.

    In other words, more than ever: When it rains, it pours.

    That’s exactly what many climate models had predicted would happen: Increasingly intense storms violently unleashing more moisture from clouds capable of holding more water.

    And experts have said that heavy rains are often thunderstorms of the hit-and-miss variety – leaving some under too much water and some wishing for more water.

  29. prokaryotes says:

    It’s the end of the world as we knew it.

    A link between climate change and extreme weather? Never.

    Scientists link extreme weather with climate change
    London: Climate change seems to have triggered extreme weather that has wreaked destruction all over the globe during the last decade.

  30. Bruce Hodge says:

    Excellent post! I couldn’t agree more.

  31. Lewis Cleverdon says:

    Looking at the graph above of modelled and observed ice-cover loss, it seems plain that the numerous models must have shared something of a group-think error; there is at least one driver active that was not appreciated. The most credible – which might just be the common missing factor – is the regional albedo loss feedback effect of rising insolation causing warmer seas to melt ice from below while also raising air temperature to accelerate melting from above. (I’d trust that the common missing factor was nothing as obvious as the rising surface-area to volume ratio of increasingly fragmented ice, or soot deposition, or the Gulf Stream’s rising heat transport to the arctic).

    The sheer number of models patently wrong indicates an honest error here, yet it needs saying that the only cases of external censorship we hear about are the unsuccessful ones – where people have refused to be censored – as in the recent debacle with Governor Perry’s shills.

    The pressures for taking conservative positions in research findings are about more than just scientific codes of credibility – they are also about career prospects and research-grant prospects under a status quo that is not keen on highly embarrassing scientific research results. This encouragement of self-censorship has to be particularly hazardous in present circs.

    The most high profile case is of course the ‘IGPCC’ decision to exclude a detailed overview of the feedbacks from each of its Assessment Reports, including the forthcoming AR5. While the feedbacks are notoriously difficult to quantify accurately, that is no excuse for failing to include observations of their accelerations to date and ‘best estimates’ of their extrapolations forward in time. To claim that such potentially catastrophic dynamics should be excluded owing to uncertainty over development rates is patently anti-science and pro-political convenience – best estimates from incomplete data is all we have for climate science overall, and including margins of error in projections is standard procedure.

    The release by NOAA/NSIDC of their estimate of carbon output from permafrost melt (Feb 17th on CP) appears to exemplify unchallenged censorship at a surprising level of institutional collaboration. The report was notable for its shortcomings in six items, including its failures:
    1. to adopt our present warming trajectory as the driver of permafrost melt rather than a moderate IPCC scenario;
    2. to include projections of warming from the other five mega-feedbacks, of which three are readily quantifiable (one per ppmv of CO2, two per degree C of global temperature);
    3. to describe permafrost emissions in CO2e rather than just in carbon;
    4. to include the consequent warming from permafrost emissions in calculating their rate of output;
    5. to provide an additional projection of warming and consequent permafrost emissions that also included warming from the loss of the sulphate parasol due to anthro-emissions’ control;
    6. to provide a clear concluding statement that, absent our early intervention in global temperature, permafrost CO2e emissions alone will cause such warming of the oceans that the future control of self-reinforcing warming is impossible.

    Without correcting other deficiencies, just the description of permafrost emissions in CO2e is sufficient to justify the missing conclusion. The report’s lame excuse for not doing so was of uncertainty over the ratio of CO2 to CH4 (methane) emissions (the latter having a CO2e value of 72 on a 20yr horizon). Given that I’m told that a literature search would have indicated that the preponderance of carbon emissions would likely be as methane, presenting the outputs as 100% CO2 seems perversely unscientific; there was a stronger case for presenting them as 100% methane, and the strongest case was for a ‘best estimate’ of the likely ratio.

    (I posted a conservative ad hoc evaluation just of the outcome of a 50:50 split on the “Open Thread” of Oct 15th at #16. This indicated a CO2e output by 2020 equal to 78% of present anthro-CO2 outputs, with a doubling a few years later).

    I’m troubled that the NOAA/NSIDC report has not raised more scientific controversy since its publication – any debate ongoing seems far from public discussion. The question of “Who benefits ?” needs asking loud and clear, as it appears that knowledge of a seminal proximate hazard – of our commitment to the irretrievable warming of the oceans – is being kept from public view.

    So what would be the effect of the report’s authors, or other institutions, providing a clear account of CO2e outputs just off the NOAA/NSIDC projection of permafrost melt rates ? Could the ‘IGPCC’ pretend to ignore it, or would its contributors finally rebel ? With the prospect of that information reaching the media and the public in less than two years, how long could the diplomatic policy of a de facto “brinkmanship of inaction” on climate be maintained ?

    I’ve seen no other pressure point where the status quo is as sensitive as it is over the implications of permafrost melt. Anything that can be done to advance the profile of this issue could be critical in terms of generating the long-awaited change of course.



  32. Artful Dodger says:

    True Jeff, all true!

    How about getting started at the AGU Fall Meeting in San Francisco this December 5-9? Can we mobilize some like-minded people to “Occupy Moscone Center”?

    I was impressed to learn that this year’s Meeting will include a session on Science Communications Training:

    “Want to be able to communicate your science easily and skillfully to non-scientists? Improve your ability to talk with the public, the press, policy makers and others at our free, all-day science communication training on Sunday, 4 December (lunch included)!”

  33. Geoff Beacon says:

    I hope this comment is allowed here. It is a reply to Myles Allen on a previous piece on Climate Progress. It is relevant here because Myles is very influential in government circles in the UK and he may be one of the scientists who underestimate climate change. In fact his last post started

    You may be right I am underestimating climate change — if I am doing my job correctly, then the odds should be 50/50.

    Dear Myles

    Thanks for replying. As you would expect I have a few comments.

    it would have been wrong to infer we had reached a tipping point in the Arctic on the basis of that single year

    I don’t want to get into “tipping points” – in practical cases they can be hard to judge and nail down their meaning. But isn’t it true that the minimum volume of sea ice has declined every year since 2007 according to PIOMAS. No sign of a recovery in sea ice volume.

    The trillionth tonne paper was about CO2-induced climate change, so the release of methane from tundra is not relevant to that paper

    Kevin Schaefer has told me:

    My estimates of carbon release from thawing permafrost are sound and the best available today. The measure of “soundness” is the 35% uncertainty, which is driven by uncertainty in the projected warming rate given a certain amount of fossil fuel emissions.

    This is a missing CO2 feedback. There are other possible ones – wildfires, burning tundra, the Amazon drying. Are these not missing CO2 feedbacks too? Are climate models with missing feedbacks being used in the preparation for AR5?

    I suspect that albedo effect from the disappearance of sea-ice is underestimated if the loss is as rapid as the extrapolations that people like Tamino are making. Are there more of underestimated feedbacks in the climate models?

    I am surprised that you dismiss methane so easily, perhaps your Trillion Tonne paper should be stamped “No added methane”. When we previously corresponded I was not sure from your answers whether your view on methane (and presumably other short term forcing agents) had been accurately reported to me by a government advisor. This was that, for the time being, short-term forcing did not matter because the effects would be gone by the time the all-important peak of concentration of carbon dioxide occurred.

    Can you clear this point up? Are short term forcing agents irrelevant to current policy options?

    Best wishes


  34. prokaryotes says:

    Non linear ice sheet behavior is only modeled with experimental models, to date.

  35. catman306 says:

    Here’s a source of terrestrial carbon that’s been left out of many models says the author.

  36. Paul Magnus says:

    The surprise is that none of the models predict we’re we are today. Not one!

  37. James Hansen’s work has been ridiculed as alarmist for its temporal predictions, but as he’s pointed out many times, his time estimates are not the result of any GCM. They are based on the geologic record. It only takes a second to look at the record of the last 400,000 years to see how quickly and decisively the climate changes state as it warms.

    Take a peek at this graph.

    400,000 years of Temps and CO2

    When the climate warms, it goes up like a rocket. And, of course, the other dreary thing about that graph is those changes are the result of Milankovich forcings that are around an order of magnitude less than that of an increase in CO2.

  38. Geoff Beacon says:

    Myles Allen has kindly replied in an email he says

    Dear Geoff,

    Of course natural methane feedbacks are relevant to the amount of CO2-induced climate change we believe we can tolerate. The problem is we don’t know what they are for different levels of warming. Current anthropogenic methane emissions are not particularly relevant to peak warming.


    The point “Current anthropogenic methane emissions are not particularly relevant to peak warming” is interesting. Is it correct?

  39. Joe Romm says:

    What does “current” matter? We’re talking about 10F warming and its feedbacks.

  40. Geoff Beacon says:


    This issue needs expanding. A far as I am aware:

    1. Those climate models that Myles Allen used had “missing feedbacks” but I don’t think he has acknowledged this.

    2. The same may also be true for similar work by Ray Pierrehumbert. I pursued this issue, with no answer, on RealClimate until Gavin Schmidt asked me to stop.

    3. Myles argues that because short-term feedbacks will have lost their effect by the “all important time” of peak forcing, their current emissions can be discounted.

    4. Does Ray Pierrehumbert argue this point too and, if so, is he supported by the others at RealClimate?

    The question is “Does the warming caused by short term forcing matter, given that it will disappear before peak forcing time?”. In the presence of feedbacks – including feedbacks that cause more CO2 emissions – the answer seems so blindingly obvious and Myles and Ray are such respected figures that I am confused. I think this must go for policy makers too.

    Others have also commented on the gap between the modellers (Allen, RealClimate &etc.) and James Hansen, whose predictions are based on the geologic record. See Jeffery Davis’s comment below.

    As this whole blog entry notes climate scientists (the modellers?) are behind the curve. Is this because of missing feedbacks?

    Worryingly, I have heard the climate models that are being used for AR5 will still have missing feedbacks. Is this true?