Tamsin’s Topsy-Turvy TED Talk

Energetic young climate scientist Tamsin Edwards, currently in the process of relocating from Bristol to the Open University, gave a TED Talk on How to love uncertainty in climate science a couple of days ago. At the time of writing there are no comments under her blog post, which is probably because she is too busy to moderate them.

There are a lot of good things in the talk.

  • Addressing the issue of uncertainty as the main topic, and acknowledging that uncertainty levels in climate science are far higher than in other areas such as experimental physics.
  • The explanation of climate models, acknowledging that they are simplifications, with the “All models are wrong” quote, and the statement that “their predictions partly depend on the numbers you plug in” and “we can’t always know what those numbers should be”.
  • Discussing the journalistic spin problem – how the same piece of research on sea level rise was reported as both “worse than feared” and “less severe than feared”.
  • It’s a well-written, clear and structured piece.

But unfortunately there are a couple of things that are completely wrong, in fact backwards:

“Not everyone knows this, but more and more climate sceptics agree with us too”

This is a recent fairy story in the climate community. In fact studies repeatedly show that people are getting more sceptical about climate change, not less.

Climate sceptics are getting more confident that they are right (that the climate scare has been greatly exaggerated), as each climate prediction fails.

In fact it is the climate scientists who are coming round to agreeing with the sceptics. After years of denying that there was any slow-down or pause in warming, it is now one of their main topics of research. Similarly, after insisting that natural variation of the climate is small compared with man-made “forcing”, they are now acknowledging, as sceptics have been saying for years, that chaotic fluctuations and natural cycles are an important factor.  As Tamsin says in her talk, climate scientists have in the past not sufficiently discussed uncertainty, leading them to make over-confident claims. The IPCC, in its latest AR5 report, has climbed down from some of the claims about extreme events made by AR4.  The IPCC has slightly reduced its range of values for climate sensitivity, as more papers come out with lower estimates. And on the policy front, while the farcical climate talk circuit continues, more and more people are realising that global agreements on mitigation are not going to happen, and that the logical approach is to adapt to climate change if/when it happens.


“That pause in warming of the atmosphere surprised the media and public, even though scientists always expected this kind of thing could happen in the short term”

This claim was made in one of Tamsin’s earlier blog posts, pause for
thought, where it was much criticised.
Climate scientists did not expect the pause.

  • The IPCC AR4 in 2007 projected 0.2C per decade over the next couple of decades.
  • The Met Office in 2007 predicted 0.3C of warming from 2004-14.
  • Lean & Rind 2009 predicted strong warming in the next 5 years.
  • Trenberth said (in 2009) “where the heck is global warming”,
    “we can’t account for the lack of warming at the moment and it is a
    travesty that we can’t.”, while Schneider spoke of someone betting a
    lot of money on a prompt upward spike, and Jones said they’d be
    worried after a 15 year pause.
  • James Annan placed a bet on warming with sceptic David Whitehouse, and lost.

The statement is backwards – it was the climate scientists themselves who were most surprised by the pause.

Remember what Feynman said: “The first principle is that you must not fool yourself — and you are the easiest person to fool.”


13 thoughts on “Tamsin’s Topsy-Turvy TED Talk

  1. I read the post on her blog and must say I was disappointed. I had seen her as a reforming voice in the echo chamber that is climate science, but her statement on the pause beggared belief. That quote from Feynman is most apposite in this case.

  2. While Tamsin seems like a really nice person, those aren’t the posts of someone who is about to meet sceptics halfway.

  3. Hi Paul, glad you liked most of it 🙂

    I don’t think you are fair about the pause because you conflate climate projections, where we don’t aim to get the timing of natural variabilty right, with decadal forecasting, where we do.

    In other words I’m saying scientists said in the literature that large-scale variability *can* act against the forced response, not that it *will* happen *from the year X* (which is very much harder).

    I know it’s paywalled, but in our Nature Climate Change article Pause for Thought (as opposed to my blog post of the same name), we say:

    “The peer-reviewed literature contains much discussion of unforced decadal fluctuations in global surface temperature and the IPCC discusses internal climate variability extensively in all of their reports. Such variability has been invoked
    to help explain both the early twentieth- century warming and the faster warming during the 1980s and 1990s. In addition, projections from global climate models have shown decadal periods of cooling embedded within longer-term warming from when they were first developed to the present.”

    I can give you the papers we cite in this paragraph if you like?

    We note that the IPCC did not include a clear statement of the chance of a slowdown in any of its Summary for Policy Maker statements (see below). Basically one would have had to deduce that short-term variability could cancel long-term forcing in the short term, because it’s not stated explicitly. I think this inference would probably be easiest from the AR1 statement.

    Maybe climate scientists mainly thought “warming of the atmosphere will be faster or slower due to natural variability”, rather than explicitly thinking it could moreorless stop i.e. exactly cancel. Either way, I don’t think you can disagree with me that the community focused too much on talking about time- and model- averaged projections, and didn’t make clear how important decadal variability is… Perhaps this was because decadal forecasting is so hard to do – the community focused more on what they were confident about.

    My career in climate science is about half the length of the pause, so I’m speculating a bit here 🙂

    I’m a big fan of the Feynman quote and included it (or at least a similar one about bending over backwards to see if you’re wrong) in my talk about him for Robin Ince’s Feynman birthday show.

    I also think your statement about scientists changing their mind is largely a question of sampling. There have always been plenty of scientists with differing views in the community, but the distribution of views in the online conversation has changed.

    Yes, there are definitely many examples of “things we thought were worrying and now think are probably not” – e.g. North Atlantic thermohaline circulation shutdown, some Greenland feedbacks. But I think that’s largely because if a high impact response is proposed as plausible, it will get a lot of attention while it’s looked into. It can take years to look at the problem – model development, ensemble simulations and so forth.

    What I *do* think has changed for many scientists is the view of how much we should engage with sceptics, answer their questions directly. And that’s a good thing!


    AR1 SPM 1990 — “the Earth’s climate would still vary without being perturbed by any external influences. This natural variability could add to, or subtract from, any human- made warming; on a century timescale this would be less than changes expected from greenhouse gas increases.”
    AR2 SPM 1995 — “Any human-induced effect on climate will be superimposed on the background ‘noise’ of natural climate variability.”
    AR3 SPM 2001 — “Changes in climate occur as a result of both internal variability within the climate system and external factors.”
    AR4 SPM 2007 — “On [regional] scales, natural climate variability is relatively larger, making it harder to distinguish changes expected due to external forcings.”

  4. Hi Tamsin, thank you for the reply.

    Halfway isn’t about nice conversations or even a figure for climate sensitivity, it’s about rewriting the past and what that bodes for the future. If every climate scientist was like you I doubt there would ever have been a problem but you’re unusual, at least for those who make a name for themselves and those who have found themselves in positions of influence.

    I doubt there are many sceptics who weren’t drawn into climate scepticism because they heard some whopper told about AGW and the biggest whopper of all was about certainty. The word consensus is a lie about certainty. There were many opportunities before 2014 to make it clear that climate is really, really complicated and modelling might well be impossible. I might be guilty of being a bit cynical to think that it’s only happening now because ‘the pause’ is becoming ‘the embarrassment’.

    To present the idea that sceptics are coming round to the idea that CO2 does have an effect is offensive. Sure, there are sceptics who think it’s all a lie but there are still warmists who think the Al Gore’s movie was a documentary rather than a work of fiction. I’ll be honest, I still don’t know what warming we’re in for and I’ve never ruled out extreme warming but I do know that making plans before you know is tantamount to lighting money on the alter of CAGW. Some of the worst solutions to problems start with a poorly defined spec and worse ones are made by people who only have one side of the story.

    The scientists did their thing and then they passed on the most lurid version to the worst people imaginable. Politicians, greens, hysterical media, Hollywood and the one group you excluded was the practical people. The ones who said ‘hang on, we have a few questions.’ Even when sceptics found fault they were ignored and when they protested at the duff solutions they were shouted down as liars and stooges for the oil companies.

    It doesn’t matter to me if sceptics and climate scientists find common ground. To meet me halfway, climate science has to stop acting like a science and start acting like the most hated but necessary business in history. It has to act like there are hundreds of greedy lawyers just panting to find a fault and sue because to withstand that you have to be very, very good. That means making sure the data is checked and double checked. It means having written standards and procedures and further procedures to make sure everybody sticks to them. It means having an aggressive regulatory body with powers to enforce and punish. It means excellent documentation, data archiving, version monitoring and duplication of experiments to ensure everybody knows the right answers. And yes, it’s every bit as horrible and inhibiting as it sounds but it’s the difference between taking climate science on trust and knowing that they can’t help but do a good job. It would mean a lot less speculative science under the AGW banner and a concentration on the most important questions.

    At that point there won’t be any credible sceptics because we’ll be happy that you really are doing your best.

  5. I might be guilty of being a bit cynical to think that it’s only happening now because ‘the pause’ is becoming ‘the embarrassment’ travesty.

    I fixed it for you.

    Tiny — the climate scientists will say that what you suggest about having to double check all data and results, all documentation in the open. with lawyers hanging in wait to sue is “not how science works”. They will ignore the fact that much medical science works exactly that way.

  6. In 1974, Lacis and Hansen introduced into GISS’ Atmospheric Science Sagan’s aerosol optical physics. It’s present in the models as the ✓3(1-g) terms. It was wrong then and it’s wrong now.

    It claims that as optical depth increases, more scattered sunlight returns to Space, asymptoting at 1.0 hemispherical albedo; ludicrous. Real Mie scattering gives 0.5; there’s a second process. Twomey knew it; his work was suppressed in 2004 to keep the ‘Global Dimming’ myth in AR4. Anyone can look at real clouds and work it out. Time for the truth to be accepted methinks.

    The second optical effect reverses the sign of the AIE It’s the real AGW and stopped ~15 years ago. There is near zero AGW from all well mixed GHGs as proved by 18 years no lower atmospheric warming.

  7. Tamsin, I don’t think I’m conflating different things. The IPCC 2007 statement, in red, in a box in the SPM, is over two decades, and ‘for a range of emission scenarios’, implying they thought it was robust.

    Then there’s the Vicky Pope video that we keep linking to, where she says, based on the Met Office 2007 paper, “By 2014, we’re predicting that we’ll be 0.3 degrees warmer than 2004. Now just to put that into context, the warming over the past century and a half has only been 0.7 degrees, globally – now there have been bigger changes locally, but globally the warming is 0.7 degrees. So 0.3 degrees, over the next ten years, is pretty significant. And half the years after 2009 are predicted to be hotter than 1998, which was the previous record. So again, these are very strong statements about what will happen over the next ten years.”

    The idea that mainstream climate scientists knew that there could well be a pause but just somehow didn’t explain it properly is an untenable bit of spin.

    I have found one two climate scientists who genuinely did predict the pause, Don Easterbrook and Dori Kovanen in a conference abstract in 2001. “If the cycles continue as in the past, the current warm cycle should end in the next few years, and global warming should abate, rather than increase, in the coming decades.”

  8. I believe TinyCO2 has captured most of what I wanted to say about the article. To me it simply made things up, like misinformation was stopping action, or whatever. How can anyone say that, the entire western world has taken on the lunatic notion that the human race has 10/12/40/60 years, take your choice, to avert disaster. So who are they trying to communicate with? And why?

    At the beginning of any enterprise the first question to be answered is. “What will winning look like”, if you can’t answer that question, it’s not worth proceeding. So I ask Tamsin and Richard what would winning look like to you in your quest to explain the uncertainties, (and their dignificance/insignificance) to dissenters.

    Tiny has dealt with it, but I’ll reiterate, a lot of what was on that blog post was incorrect which gave rise to me asking Tamsin to talk to sceptics, she said she did regularly, so I advised listening, because, in my view at least, I’ve never seen a discussion with either Richard, or Tamsin, that was about the uncertainties. At least not one where the sceptics got to speak.

    The clisci community are obsessed with “communications” and over the last six month or so there have been a number of conferences/meetings and away days to discuss it. As far as I’m aware no one from their target audience, the dissenters, has been at any of them. Communicating isn’t didactic it requires the communicator to listen to their target audience and understand what they believe.

    Unless, of course, what winning looks like is persuading the dissenters they’re wrong because their beliefs don’t resonate with popular opinion.

    I’ll be blunt I thought it was a poor piece:

    “Complexity and uncertainty create extra difficulty for experts in explaining their results, and for non-experts in understanding them. Climate science is not sound bite science.”

    That I would unequivocally repudiate. It is exactly that, “a sound bite science”. Maybe not in the back rooms of academia it isn’t, but in the front parlours of politics – where it is front and centre – it is probably the most sound bite driven science in history.

    Tamsin isn’t listening, not just to me. she would do well to tell us what winning looks like to her when communicating with dissenters.

    By the way Tamsin, I wish you well in your new job, good luck with it.

  9. One key piece of evidence to prove that climate science still hasn’t conveyed complexity to the wider world – public, media and politicians – it’s the question ‘do you believe in climate change?’ It contains much that is wrong with the present situation. First it ignores the issue that climate always changes and the question doesn’t distinguish between natural and man made, let alone what percentage each contributes. Second it opens the opportunity for climate to be linked to CO2 without necessary warming to trigger it. And most important, it makes no attempt to find out if the subject has grasped anything about the range of possibilities predicted by climate science. I doubt many people could tell you the best and the worst scenarios under the IPCC reports possibilities for 2100 let alone discuss the outliers that exist in the literature both high and low. If even the communicators for climate science don’t realise how flawed the question is, how good has the communication been?

    Does anyone here think that if key politicians and other influential people were asked to identify the flaws in Al Gore’s movie they could point them out?

  10. Some relevant comments from James Annan’s blog:

    “And despite what some people might like to think, the slow warming has certainly been a surprise, as anyone who was paying attention at the time of the AR4 writing can attest. I remain deeply unimpressed by the way in which this embarrassment has been handled by the climate science insiders, and IPCC authors in particular. Their seemingly desperate attempts to denigrate anything that undermines their storyline (even though a few years ago the same people were using markedly inferior analyses of this very type to bolster it!) do them no credit.”

  11. @ “Climate scientists did not expect the pause.”
    A much bigger surprise happened when the last global cooling started (1940-1970), about which an observer at Kew Ob noted in 1943 (details from http://climate-ocean.com/a2005/02_16-Dateien/02_16.html ) wrote:
    __ “The present century has been marked by such a wide-spread tendency towards mild winters that the “old–fashioned winters”, of which one has heard so much, seemed to have disappeared forever. The sudden arrival at the end of 1939 of what was considered to be the beginning of a series of cold winters was therefore all the more surprising.” A.J. Drummond, QJMet.o.R.Soc. (1943). The reference discuss the impact of WWII.
    Old stuff may provide good hints.

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