Myles Allen and Guardian Must Retract Phony Quote on Al Gore’s Views of Link Between Climate Change and Weather

Top climatologist Calls Key Allen Critique “clearly wrong.”

Myles Allen, with the complicity of the UK’s Guardian, has put words into Al Gore’s mouth in order to attack the Nobel-Prize winning former Vice President.  What makes this attack a particularly egregious breach of journalism is that Allen and the Guardian could have avoided it had they spent even 30 seconds reading their own damn links.

As we’ll see, what Gore is actually saying about the link between extreme weather and climate change is something countless scientists and independent experts have been saying — and throughout this post I will run through what many of the experts have said.

Indeed, the journal Nature just ran a story just last month with this headline:

Climate and weather: Extreme measures

Can violent hurricanes, floods and droughts be pinned on climate change? Scientists are beginning to say yes.

It is in this context that we have this phony attack on Gore in the Guardian:

Al Gore is doing a disservice to science by overplaying the link between climate change and weather

To claim that we are causing meteorological events that would not have occurred without human influence is just plain wrong

When Al Gore said last week that scientists now have “clear proof that climate change is directly responsible for the extreme and devastating floods, storms and droughts that displaced millions of people this year,” my heart sank. Having suggested the idea of “event attribution” back in 2003, and co-authored a study published earlier this year on the origins of the UK floods in autumn 2000, I suspect I may be one of the scientists being talked about.

When I read this my heart sank since I knew, once again, that Gore was being defamed yet again for something he didn’t actually say.  I’ve never heard Gore talk this way, particularly using a phrase like “directly responsible” in this context.  Also, I had interviewed Gore months ago and knew which  scientists he had been talking about.  The list he gave didn’t include Allen.  Go figure!

Allen may be a scientist, but he apparently can’t be bothered to even read the links he uses.  I guess the Guardian‘s fact-checkers are as nonexistent as the Washington Post‘s because the link is to another (dreadful) Guardian story:

Al Gore: clear proof that climate change causes extreme weather

Former US vice president tells Scottish green conference that evidence from floods in Pakistan and China is compelling

Al Gore has warned that there is now clear proof that climate change is directly responsible for the extreme and devastating floods, storms and droughts that displaced millions of people this year.

That’s right, the claim that Gore said scientists have “clear proof that climate change is directly responsible” for this year’s extreme weather is false. It was a Guardian journalist’s (mis)reporting of what Gore said.

Had I seen this first nonsensical story at the time, I’d have debunked it, but then I could spend all of my time debunking dreadful media coverage.

The Guardian and Allen owe Gore a retraction and apology.  Let’s see if they have the decency to do so.

This phony quote is now racing through the bunkosphere and no half-hearted correction will fix this.

Gore perhaps more than any modern figure has been attacked for things that he didn’t actually quite say (see, for instance, here), so people who recklessly smear him deserve no sympathy.

Indeed, reporters are now so terrible at paraphrasing him that I am beginning to suspect their ability to even report what he actually said.

Let’s try to distinguish what Gore actually said from what the Guardian claims he said.  Yes,  I know that this still means trusting the reporter got the direct quotes accurate, which is  obviously doubtful, but it’s all we have right now.  I can’t find the talk online, though no doubt it is very similar to his closing talk of the 24 Hours of Reality.

In a near hour-long speech to the Scottish low-carbon investment conference, Gore said the evidence from the floods in Pakistan, China, South Korea and Columbia was so compelling that the case for urgent action by world leaders to combat carbon emissions was now overwhelming, Gore said [sic!!!]

[Yes, the Guardian hasn’t corrected that editorial mistake in two weeks — where are the copy editors?]

That may have been what he said, but given that Gore said the case was compelling back in 2006, who knows if the reporter got this right?

“Observations in the real world make it clear that it’s happening now, it’s real, it’s with us,” he said. Failing to take action meant the world would face a catastrophe.

Again, this is true of global warming and climate change.  Dr. Richard Somerville, a coordinating lead author on the IPCC’s 2007 review of climate science, told ABC this year: “This is no longer something that’s theory or conjecture or something that comes out of computer models. We’re observing the climate changing. It’s real. It’s happening. It’s scientific fact.”

He added that nearly every climate scientist actively publishing on the subject now agreed there was a causal link between carbon emissions and the sharp increase in intense and extreme weather events seen across the globe.

Gore’s statement is on strong scientific grounds — since it is a statistical one (see literature review here: Two seminal Nature papers join growing body of evidence that human emissions fuel extreme weather, flooding that harm humans and the environment).  But again, it’s not a direct quote, so we don’t know if Gore said it.

“Every single national academy of science of every major country on earth agrees with the consensus and the one’s that don’t agree with it do not exist. This is what they say to governments: ‘The need for urgent action is now indisputable’.


“The scientists have made a subtle but profound change in the way that they speak about the connection between the climate crisis and the extreme weather events. They used to say you can’t connect any extreme weather event to climate because there are multiple factors. Now they’ve changed.

“The environment in which all storms are formed has changed. It’s influence is now present according to the leading scientists in all storms, and they speak of relative causation.”

True again.

Gore told me in July:

“I have paid very careful attention to the way Jim Hansen and Kevin Trenberth and other leading climate scientists have shifted the way in which they frame this connection….

Both Jim and Kevin, as well as others, have gone to some lengths to reframe that characterization by saying, if you ask the question “would this have happened in this way without the climate crisis?” the answer is almost certainly no.

Kevin Trenberth is distinguished senior scientist at the National Center for Atmospheric Research.  He told the NY Times in a story headlined “In Weather Chaos, a Case for Global Warming“:

“It’s not the right question to ask if this storm or that storm is due to global warming, or is it natural variability. Nowadays, there’s always an element of both.”

For more on Hansen’s thinking, see NASA’s Hansen: Would recent extreme “events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?” The “appropriate answer” is “almost certainly not.”

The original Guardian story continues:

Gore said there was now evidence that the globe’s hydrological cycles were changing: as the atmosphere and oceans warmed, more water was evaporating and getting stored in the atmosphere. The amount of water vapour over the oceans had increased by 4% in 30 years, particularly around the tropics and sub-tropics….

Gore then cited a recent report from the global insurance Munich Re, that climate change was “the only plausible explanation” for the rapid increase in extreme weather events. “They’re paid to get this right. It’s their job,” he said.

Correct again.

A year ago September, Munich Re issued a news release, “Large number of weather extremes as strong indication of climate change,”

… it would seem that the only plausible explanation for the rise in weather-related catastrophes is climate change. The view that weather extremes are more frequent and intense due to global warming coincides with the current state of scientific knowledge as set out in the Fourth IPCC Assessment Report.

Peter Hoppe, Head of the Geo Risks Research Department at Munich Re, wrote me:

For me the most convincing piece of evidence that global warming has been contributing already to more and more intense weather related natural catastrophes is the fact that while we find a steep increase in the number of loss relevant weather events (about tripling in the last 30 years) we only find a slight increase in geophysical (earthquake, volcano, tsunami) events, which should not be affected by global warming.

But Allen apparently considers himself the arbiter of what can and can’t be said on this subject.  Well, many leading scientists dispute his perspective and back up Gore.

Allen writes in his piece:

So when Gore says: “the environment in which all storms are formed has changed,” he isn’t actually lying, but he is begging to be misunderstood.

That is beyond a cheap shot. Here is what Trenberth told the NY Times in June:

“Global warming is contributing to an increased incidence of extreme weather because the environment in which all storms form has changed from human activities,” Dr. Trenberth said in a telephone interview Wednesday. “Records are not just broken, they are smashed. It is as clear a warning as we are going to get about prospects for the future.”

Texas Climatologist Katherine Hayhoe wrote Climate Progress last month:

We often try to pigeonhole an event, such as a drought, storm, or heatwave into one category: either human or natural, but not both. What we have to realise is that our natural variability is now occurring on top of, and interacting with, background conditions that have already been altered by long-term climate change.

As our atmosphere becomes warmer, it can hold more water vapor. Atmospheric circulation patterns shift, bringing more rain to some places and less to others. For example, when a storm comes, in many cases there is more water available in the atmosphere and rainfall is heavier. When a drought comes, often temperatures are already higher than they would have been 50 years ago and so the effects of the drought are magnified by higher evaporation rates.

So Gore made a completely accurate statement, one that leading scientists have made, and Allen/Guardian write, “he isn’t actually lying.”

That is another shameful sentence that  should be retracted.

Gore isn’t begging to be misunderstood.  He explains at great length exactly what he means — he means there is more moisture in the atmosphere to be swept into storms, and there are higher temperatures that worsen heatwaves and have myriad other impacts.

Allen writes:

People deserve to know how much climate change is affecting them, and not be fobbed off with banalities like: “this is the kind of event that we might expect to become more frequent.”

But the fact that a method exists for establishing whether or not a statement is true does not mean that it is true, still less that anyone has done the study to find out.

Trenberth wrote me:

I take issue with this.  Here there is clearly an underlying assumption that the climate has not changed and so we have to prove that it has.  This is clearly wrong, because we know for a fact that the climate has changed and the environment that all weather events now form in is different than in the past (say more than 30 years ago).

The bottom line is that the Guardian and Myles Allen don’t speak for science.  They aren’t in a position to say that anybody is doing a disservice to science — particularly given their own egregious blunder and overstatements.

All of Gore’s direct quotes cited in the Guardian articles are eminently defensible statements that many leading scientists have made.  Allen is entitled to his own opinion, but  he has no business smearing Gore over their differences, especially the way he did.

Time for an apology and retraction.

19 Responses to Myles Allen and Guardian Must Retract Phony Quote on Al Gore’s Views of Link Between Climate Change and Weather

  1. caerbannog says:

    OT, but worth mentioning — folks attending the GSA meeting in Minneapolis might be treated to a freak-show outside the main entrance tomorrow.

    See for the (very silly) details.

  2. Rob Jones says:

    OT again but it’s great news so I’ll share it.
    The Australian government has passed a bill to put a price on carbon emissions. This has yet to pass our senate but that is expected to be a mere formality.

  3. When Allen states:

    So when Gore says: “the environment in which all storms are formed has changed,” he isn’t actually lying, but he is begging to be misunderstood.

    … I suspect that he means to smear not simply Al Gore but the shift in emphasis from “we cannot say that global warming was *the* cause of any given weather event” to “global warming has increased the water vapor in the atmosphere, increasing the level of moisture and latent energy that is in the environment in which all storms form and is in all likelihood a major factor in any once highly improbable weather event”.

    Al Gore is an easy target. He isn’t a scientist but simply someone who is highly intelligent and listens very closely to what scientists say and explains it so that others may understand. He has a long and well established reputation for misrepresenting the science. The fact that this reputation is entirely unearned isn’t beside the point, but icing on the cake.

    Smear Al Gore for repeating what the scientists are already saying and you can smear the shift in emphasis without acknowledging that any scientists are improving the framing of their causal analysis. You may even discourage others from adopting the new framing — as they would be repeating the silly mistake or falling for transparent propaganda of Al Gore — despite the fact that they may easily have gotten their ideas from elsewhere, e.g., the same scientific sources as Al Gore.

  4. Paul magnus says:

    Thanks for this Joe. Always on top of the bs in the msm!

  5. Geoff Beacon says:

    I have had a few email exchanges with Myles Allen and I got the impression that he underestimates climate change. On one of my blogs I wrote one posting about a report in the Times about the low extent of Arctic sea ice in 2007 where he said:

    Some claims that were made about the ice anomaly were misleading. A lot of people said this is the beginning of the end of Arctic ice, and of course it recovered the following year and everybody looked a bit silly.

    This didn’t seem to fit with other sources I had been following and the posting ended:

    Vicky Pope and Myles Allen are serious people but will they be the ones that look silly?

    You can guess my thoughts now.

    In another blog, I have questioned Allen et al, “Warming caused by cumulative carbon emissions towards the trillionth tonne”

    They said

    Total anthropogenic emissions of one trillion tonnes of carbon (3.67 trillion tonnes of CO2), about half of which has already been emitted since industrialization began, results in a most likely peak carbon-dioxide induced warming of 2 degrees Celsius above pre-industrial temperatures, with a 5–95% confidence interval of 1.3–3.9 degrees Celsius.

    I said

    It is apparent that certain climate feedbacks have not been incorporated into the computer simulations used by Allen et. al. but this paper has installed the peak level of carbon dioxide as the keystone in current government thinking.

    Al Gore is not a climate scientist. Myles Allen is. I am not a climate scientist.

    I gather from your piece that Gore is right and Allen is wrong.

    I also think that I was right (twice) and Allen was wrong.

    I make that

    Amateurs 3 Climate Scientists 0.

    Don’t misunderstand me. I do think climate scientists are key to our understanding (I would use a stronger expression if I had time to think of one) but we may have fallen into the danger of thinking in terms of Gods and Mortals. This brings me to the Olympian meeting of our climate gods, the IPCC.

    It’s Olympian tasks hardly get anything wrong but when they occasionally do they are severely punished. So many worrying things that are possibilities are pencilled in their reports (e.g. feedbacks from Arctic tundra). My experience tells me that government policy makers are prone to rub out the pencil markings.

    What we need is higher counsel than the IPCC that can discuss these pencil markings which may turn out to be big threats. We have a what the systems theorists call a wicked messy problem that is more akin to a military problem than a scientific one. It cannot be left to scientist alone because too many of them will not pronounce until they are certain. We haven’t the time for certainty.

  6. Stephen Watson says:

    “… a particularly egregious breach of journalism”

    What on earth constitutes such a breach of journalism and who is supposed to hold them to account over such a ‘breach’? Over the years here in the UK they have smeared, trashed and distorted people’s lives again and again. They print falsehoods in blazing headlines on the front page and (perhaps) retract them in tiny print on page 12 the following week. Still Joe, you have this endlessly hopeful expectation that the MSM reports fairly, accurately and truthfully on events and on what people say, even Al Gore.

    The papers, including the ‘heavyweights’ regularly misquote, distort and twist things to match their agenda or else do it out of simple laziness.

    EVERYONE I have spoken to who has had dealings with the press can tell tales of lies and errors. This happens even for utterly non-contentious stories. My Mum worked for a VW garage which was about to sell it’s 1,000th Golf so they invited the local press for some PR. My Mum was amazed the following day to see that in a column 1 inch long the journalist had got the date of the event, the name of the couple buying the car and even the garage’s name wrong (despite it being in foot high letters all over the front of the garage)!! I have given a talk on LETS totally twisted by a ‘respectable’ national UK newspaper – all the quotes from me were correct, but they left out a lot of what I said a re-assembled those they used to make me look very financially cynical indeed. Someone I worked with vowed never to talk to the press ever again after they had totally altered what she had said about … the boy scouts and their new hut!

    I could go on … and on, but I won’t.

    The media are corporations supporting a lot of very large corporate advertisers who spend a lot advertising cars, cheap flights and essentially, rampant consumerism in their ‘lifestyle and fashion’ pages and they are not wanting to cause too much cognitive distress to their readers by getting them worried about whether they should travel or buy less by reporting worrying tales of climate change.

    The link here is but one of many on MSM double-think and duplicity on the excellent MediaLens site:

  7. Anne van der Bom says:

    I think Myles Allen is trying to reach out to deniers and gain credibility with them by bashing The Most Hated One. Al Gore.

    In effect he’s pulling a ‘Judith Curry’.

  8. zach says:

    Thanks, Joe.

    I saw that in RSS when Guradian published it and thought, “WTF? That doesn’t sound like Al Gore at all. And this doesn’t seem like a typical Guardian piece at all.”

    My guess is they got approached by a “climate scientist” to write a piece and didn’t realize what they were getting into (and, of course, didn’t fact check the scientist).

    But really, anyone publishing in the “green” field should know by now what the connection is and what Al Gore’s said about it. (esp the major media companies..)

    if only we lived in a common sense world..

  9. Mulga Mumblebrain says:

    zach, amigo, this is a typical Guardian piece these days, all too typical.

  10. Spike says:

    What is galling is that he condemns a cautious statement as a banality, then slags off Gore for being too directly attributional. It is scientific purism which is so rigid it means we cannot reach out to the public to discuss risks in a sensible way. He seems to say “wait 5 years for us to do the modelling”. Hardly something likely to spur appreciation of the gravity of our situation.

  11. Hi Joe,

    First, let me say that the Guardian takes accuracy very seriously on any subject but particularly one as important as climate change. So we look carefully at any claim that an article has fallen short of this standard.

    The quotes in this piece were transcribed from a recording of the lecture. They are an accurate record of what Gore said. No one who attended and heard the lecture has challenged that.

    So I think the issue comes down to whether the top line of the news piece is a reasonable paraphrase of the point that Gore was making. I think it is.

    This quote from the original story is relevant:

    “The scientists have made a subtle but profound change in the way that they speak about the connection between the climate crisis and the extreme weather events. They used to say you can’t connect any extreme weather event to climate because there are multiple factors. Now they’ve changed.”
    “The environment in which all storms are formed has changed. It’s influence is now present according to the leading scientists in all storms, and they speak of relative causation.”

    And here is some further material from the transcription of the lecture. Some of this appeared as a quote in the original news article.

    “The observations in the real world make it clear it’s happening now. It’s real. It’s with us. They used to say we’re changing the odds, we’re loading the dice that make it more likely that we’ll get extreme weather events. Now the change is we’re not only loading the dice, we’re painting more dots on the dice. We’re not only rolling more 12s, we’re rolling 13s and 14s and soon 15s and 16s. In other words the big storms are both more frequent and bigger.
    “Jim Hanson is, in the minds of many, the most distinguished climate scientist in the world. And he turns this question around. Were the Pakistani floods and these other events caused by global warming? He says if you ask the question this way: Would these things have happened in the absence of all this extra heat-trapping pollution in the atmosphere? If we had not increased it by 40% so far? 
    “No. Almost certainly they would not be happening, except for changes that we have wrought.”
    [Here he turns to a slide on the overhead]
    “So here is the linkage spelt out directly between the climate crisis and the severity and frequency of the extreme weather events: as CO2 goes up so does temperature, it has been measured for a long time and is one of many measurements [digresses into explaining a slide]”.

    Note that Gore used the word “directly” in the context of attributing extreme weather events to climate change which we mirrored in the top line of the story. This is an attempt to encapsulate the message in this section of Gore’s speech, but anyone reading the piece will be clear that the first sentence of the story is not a direct quote from Gore himself.

    The second point regards Myles Allen’s comment piece. The quotation at the top was from the news article – it included a link to make that clear – but I accept there may have been some ambiguity here. Clearly some readers have regarded the paraphrased top line of the news piece as a direct quote from Gore, so we have now removed the quote marks and included a clarifying note at the bottom of the comment piece.

    Yours Sincerely

    James Randerson
    Environment and science news editor, The Guardian

  12. Joe Romm says:

    This is weak.

    First off, at least now you acknowledge Gore was quoting leading scientists like Hansen.

    Second, the article claims “Al Gore said last week that scientists now have clear proof that climate change is directly responsible for the extreme and devastating floods, storms and droughts that displaced millions of people this year, my heart sank.”

    Gore said, “here is the linkage spelt out directly between the climate crisis and the severity and frequency of the extreme weather events: as CO2 goes up so does temperature, it has been measured for a long time and is one of many measurements.”

    There is actually a big difference between those 2 statements. The first asserts climate change is directly responsible for these events. The second says there is a direct link between climate change and ” the severity and frequency” of the events.

    I guess I’ll have to do another post.

  13. Sou says:

    I’m with Joe Romm on this one, James. What Allen wrote and what you quoted Gore as saying are quite different. I was bemused by Allen’s article, not seeing the point of it.

    Now I am surprised by your reply. The way I read it, ‘directly’ in the quote you provided refers to the fact that global warming affects all weather, including extreme weather.

    Heck, it’s been so wet in so many places this past few months that the oceans are visibly losing water and sea levels have dropped a lot. Too many countries to name have been flooded. Plus heat records broken everywhere.

    That article would have been the norm for the Sunday Mail maybe, but not the Guardian.

    Is Myles Allen the equivalent of a USA Libertarian I wonder? (His article came across as a political piece not a science article.)

  14. Geoff Beacon says:


    You see from the comments above I feel that Myles Allen underestimates climate change.

    From contact with UK Government I had previously judged that he has been very influential on their policy. I have now changed my judgement from “influential” to “useful” – I suspect the Government leans towards scientists that have views that are not too disturbing to their policies. See my piece The Department of Energy Security where you will see that I raised the issue with Chris Huhne, with no response – despite his assurances. I think it time that the Guardian addressed this important topic.

    I have already emailed Jo Corfino and Fiona Harvey on your disappointing article – but perhaps you already know that. As a frequent Guardian reader since 1959 I am sad to think that the Guardian has not come up to scratch on this occasion.

    Best wishes

    Geoff Beacon

  15. Myles Allen says:

    Dear Joe,

    Kevin Trenberth did not call my critique of Al Gore “clearly wrong” — he called the underlying assumption that the climate has not changed clearly wrong. This is not an assumption I make (I don’t assume the converse either). The evidence suggests that the climate has changed in such a way to make some kinds of extreme weather event more frequent, and some (like extreme polar lows, for example) less frequent.

    To say that “the environment in which all storms are formed has changed”, without making clear that the impact could be in either direction or, indeed, too small to be detectable, is begging to be misunderstood. It implies (and the Guardian journalist reporting on Al Gore certainly understood it to imply) that human influence on climate is somehow partially to blame for most observed instances of extreme weather.

    [JR: Except Gore’s original video is online for all to see — and Gore discusses what he and Trenberth and Hansen mean at length. The reporter misreported it, but that isn’t Gore’s fault. And you misreported it, also not Gore’s folk.]

    In fact, human influence on climate has increased the risk of some observed weather events, while others may have occurred in spite of having been made less likely by human influence. We may have also avoided some potentially damaging weather events (like the hypothetical snow-melt flood) thanks in part to human-induced warming. Many other events will not have been significantly affected either way. It is an emerging branch of climate science to sort out which are which. It is important, ultimately for the sake of those who really are being adversely affected by climate change, not to prejudge the outcome.

    [JR: Yes, but the literature is clear on what events have become more common and extreme. And so is Gore and the scientists he cites. The piece should still be retracted.]

    I agree with you that the sub-header of the Comment piece is wrong: it misquotes what I actually said in the comment, changing “could not have occurred” to “would not have occurred” (see my post at 6:15 that evening, which was the first time I saw this sub-header: as you probably know, contributors do not get to write the headers). I of course asked the Guardian to correct it then and there, and I am still hoping they may do so.


    Myles Allen

  16. Myles Allen says:

    Dear Joe,

    James Hansen is, of course, a great climate scientist, but he isn’t a specialist in event attribution. The statement “They used to say we’re changing the odds, we’re loading the dice that make it more likely that we’ll get extreme weather events. Now the change is we’re not only loading the dice, we’re painting more dots on the dice,” is not supported by the scientific literature. I am not aware of a single published paper that claims that a damaging weather event has occurred that could not have occurred in the absence of human influence on climate(1). Scientists who work in this area still talk in terms of changing odds (see the Nature review that you cite). What is new is that we are starting to think we can quantify that change.



    [JR: You might try reading the IPCC for starters. Obviously we’ve warmed unequivocally — so we’ve shifted the bell curve on warming. That must perforce mean we are painting numbers on the dice that control how intense heat waves and droughts are. Then we have the extra 4% of water vapor in the atmosphere, which makes rain events more intense, as Trenberth says in his latest paper, which you must seen. Trenberth work in this field and he simply disagrees with you.]

    1) A possible exception might be Christoph Schaer’s 2004 paper on the European heatwave, which assigned it a very long return-time in a natural climate, so long that it might be legitimate to paraphrase it as “never”, but subsequent research by that group has found that this return-time might have been overestimated through the assumption of Gaussian statistics (a point which is also acknowledged in their 2004 paper).

    [JR: The literature says it is now warmer than than the warmest NA drought in past 1200 years, for instance.]

  17. Myles Allen says:

    Dear Joe,

    Yes, the evidence indeed suggests we are shifting the bell curve — but the whole point is that as you shift the bell curve, you change the probability of thresholds being exceeded. You don’t cause events to occur that could not have occurred otherwise. The changes in risk may be substantial, but we are still talking about loading the dice, not painting on more dots. The point on which Kevin Trenberth and I disagree is not this one, but whether it is appropriate, in the face of the evidence now available, to continue to use the null-hypothesis of no human contribution to the risk of a given weather event, warming trend or whatever, as a starting point. I know he feels it is time, in effect, to reverse the burden of proof, and while I see where he is coming from, I don’t think I am alone in disagreeing with him on this one.


  18. Geoff Beacon says:


    Am I wrong to suggest that you underestimate climate change? There are two issues that concern me.

    First did the Times report you correctly as saying that the Arctic sea ice recovered after 2007? I understood that while the minimum extent might have recovered somewhat, the minimum volume of Arctic sea ice kept falling. Wasn’t it one of the characteristics of the 2007 Arctic summer that the sea ice was piled up by the effect of winds so had less extent and this was not repeated so much in later years?

    Secondly, in your “Warming caused by cumulative carbon emissions towards the trillionth tonne” did you use computer models that did not account for some climate feedbacks, such as carbon released by melting Arctic tundra as carbon dioxide and methane? If so, which recognised climate feedbacks were missing?

    If these were missing and were now to be included, what temperature rise would be expected from releasing the trillion tonnes? Have you revised your original estimate?

    Best wishes

    Geoff Beacon

  19. Myles Allen says:

    Dear Geoff,

    You may be right I am underestimating climate change — if I am doing my job correctly, then the odds should be 50/50. As you say yourself, the 2007 sea-ice anomaly was partly circulation driven, and current models are not really good enough to assess how much is was circulation driven, so it would have been wrong to infer we had reached a tipping point in the Arctic on the basis of that single year. That was the point I made to the Times, and it remains valid.

    The trillionth tonne paper was about CO2-induced climate change, so the release of methane from tundra is not relevant to that paper. I know there is an ongoing debate about permafrost stability, but it isn’t a field I specialise in. We are hoping to update the numbers for AR5 to allow for the latest estimates suggesting a small downward revision in the warming to date attributable to CO2. This will probably result in a small downward revision of our estimate of cumulative warming commitment, but (before the bloggers get too excited about this), still well within our range of uncertainty and that of other published estimates.



    PS — this is my second attempt at posting this — hopefully Joe will let it through this time.