Category Archives: detection and attribution

Hurricane Sandy and the Climate Hens

Image courtesy of NASA, used under Creative Commons

Hurricane Sandy is one for the record books in a number of senses, and as New York and the world struggle to grapple with its enormity, some discussion has turned to climate change. A topic that has been damningly absent from discussion in the U.S. Presidential election.

It is inevitable that when anyone anywhere tries to talk about climate change in relation to things in the here and now rather than some murky, distant future, a particular group descends to cluck their tongues and admonish everyone that climate change can’t be tied to any individual event (a proposition that is not true, and grows increasingly less defensible as the field of fractional attribution matures). This group includes many who also fall into the camp of those who style themselves as non-partisans or above the “tribal” nature of climate debates. The parallels with Jay Rosen’s larger media critique of the View from Nowhere have been noted by Michael Tobis among others.

Dave Roberts has a thoughtful piece about this phenomenon. He refers to this group as climate “scolds” in contrast to climate hawks (and yes, I do have my own problems with the latter moniker). And while I do think that “scold” captures a lot of the flavor of the group Roberts is describing, I think the hawk vs. “___” setup favors a different term for the group: climate hens.

Image courtesy of Flickr user “Ann Blair”, used under Creative Commons

Climate hens by and large acknowledge the human perturbation of the climate system. But they are very, very hesitant to highlight (or are even downright resistant to) the idea that humans are shaping the present climate in ways that are affecting the public now. This may be because it doesn’t jibe with what they learned about climate years ago. It may be because they view erring on the side of making climate change seem more serious than it is to be as bad or worse than denying that it’s a problem. It may be because they don’t really understand climate science very well- Eric Berger and Roger Pielke Jr., for instance, are two climate hens that have displayed a remarkable ignorance about basic aspects of climate science pertaining to natural variability in a warming world. (Pielke Jr. is also infamous for playing bait and switch by turning conversations about human contribution to extreme events into discussions about an economic signal in normalized disaster losses.) Whatever the reason, climate hens are just plain uncomfortable with people attempting to tie extreme events to our increasing influence on the planet’s climate.

Roberts points out, correctly and convincingly, that the climate hens are clucking about a problem that doesn’t really exist- at least not the one that they’re ostensibly worried about. When the general public sees something like the record US heat, the summer drought, or a hurricane like Sandy, and they start asking about global warming, they don’t really want a belabored lecture on fractional attribution or paleoclimatic precedents that the climate hens think should determine the answer. What the public is looking for is some way to connect this thing- that scientists are telling them is real and a real problem- to their own experiences of the world. That’s what we humans do. Climate hens are, by mistake or by design, frustrating one of the best avenues of facilitating public recognition of climate change as a problem they need to take seriously. Roberts frames it this way:

That’s the key missing ingredient on climate change: not a technical understanding of stochastic modeling, forensic attribution, and degrees of probability, but a visceral, more-than-intellectual sense of what climate change means. Most people simply lack a social and ethical context for it, so they end up jamming it into other, more familiar contexts (“big government,” “environmental problem,” “liberal special interest group”).

A storm like Sandy provides an opportunity for those who understand climate change to help construct that context. It provides a set of experiences — a set of images, sounds, smells, feelings, experiences — that can inscribe climate change with the cultural resonance it lacks. That’s what persuades and motivates people: not the clinical language of science, but experiences and emotions and associations. Of course communicating scientific facts is important too, but it’s not the primary need, nor the standard by which other communications should be judged. What scolds often do is interpret the language of emotion and association through the filter of science. That’s neither helpful nor admirable.

And this perspective has supporters amongst those studying climate communication. Elke Weber (2010) makes this point:

Behavioral research over the past 30 years strongly suggests that attention-catching and emotionally engaging informational interventions may be required to engender the public concern necessary for individual or collective action in response to climate change… To the extent that time-delayed consequences of our actions do not attract the attention or generate the concern ex-ante that they would seem to warrant ex-post, behavioral research provides some corrective actions. The concretization of future events and moving them closer in time and space seem to hold promise as interventions that will raise visceral concern.

The science of tropical cyclogenesis in a warming world is undoubtedly complex and uncertain- a point I’ve been making for years. But when the public starts asking questions about climate after an event like Hurricane Sandy, they aren’t looking for navel-gazing about ensembles of modeling runs, wind shear, and overwash sediment coring. They are asking for a way to connect something they keep hearing they are supposed to care about to things they already do. The proper response to such questions is not, as the climate hens would have it, to shut them down and turn them away. And it should go without saying that nor is it a reason to overstate the connections between our increasingly heavy influence on the climate and extreme events like Hurricane Sandy. Rather, the appropriate response is to treat the questions for what they are: an invitation to talk about climate change in a way that is meaningful to a curious but decidedly lay public. Climate change means sea levels rising, it means storm surge increases, it means heavier precipitation events (Schaeffer et al., 2012; Sriver et al., 2012; Shepard et al., 2012; Min et al., 2011). If Hurricane Sandy makes these threats more concrete, if it moves them closer in time and space, if- in Roberts’ words- it provides “a set of images, sounds, smells, feelings, experiences”, we should absolutely be talking about it. And perhaps something good will come of this disaster. Clucking from the climate hens be damned.

References

  • Min, S.-K., X. Zhang, F. W. Zwiers, and G. C. Hegerl (2011), Human contribution to more-intense precipitation extremes, Nature, 470(7334), 378–381, doi:10.1038/nature09763.
  • Schaeffer, M., W. Hare, S. Rahmstorf, and M. Vermeer (2012), Long-term sea-level rise implied by 1.5 °C and 2 °C warming levels, Nature Climate Change, doi:10.1038/nclimate1584.
  • Shepard, C., V. Agostini, B. Gilmer, T. Allen, J. Stone, W. Brooks, and M. Beck (2012), Assessing future risk: quantifying the effects of sea level rise on storm surge risk for the southern shores of Long Island, New York, Natural Hazards, 60(2), 727–745, doi:10.1007/s11069-011-0046-8.
  • Sriver, R., N. Urban, R. Olson, and K. Keller (2012), Toward a physically plausible upper bound of sea-level rise projections, Climatic Change, 1–10, doi:10.1007/s10584-012-0610-6.
  • Weber, E. U. (2010), What shapes perceptions of climate change?, Wiley Interdisciplinary Reviews: Climate Change, 1(3), 332–342, doi:10.1002/wcc.41.

Matt Ridley needs to take some advice from Matt Ridley

Matt Ridley is a techno-optimist of the Lomborgian mold, with all of the cherry-picking and source misrepresentation that goes with it apparently. He gave a speech to the Royal College of Physicians of Edinburgh [corrected – see below] that has “skeptics” falling all over themselves in delight.

What groundbreaking evidence does Ridley marshal in defense of his rejection of mainstream science?

I was curious. Ridley ostensibly is a cut above the average denizen of WUWT. He was trained as a zoologist before taking up science writing. He has articles frequently published in the mainstream press, as the delicious-in-hindsight tweet by Andy Revkin reflects. He’s widely acclaimed for popularizing science concepts for mainstream reading audiences. So whatever Ridley had must be good, I thought. His arguments would reflect the best of the “skeptics’” best.

It turned out I was wrong. Or perhaps, I was right, and Ridley was bringing the best of the “skeptics’” best. Either way, it was an enormous disappointment. Ridley’s speech turned out to be a textbook Gish Gallop, full of false claims, logical fallacies, and trivially true but irrelevant “facts”. It was, as I put it at Keith Kloor’s blog, “skeptic” bingo.

  • Sea level rise is small and is decelerating!
  • Methane isn’t increasing!
  • Hockey Stick!
  • Etc.

I don’t think I will do a point by point rebuttal to every claim in Ridely’s speech at this time (maybe later, for sport, time permitting). But suffice it to say that while Ridley is being lauded by the denialosphere now, he’s actually done them a tremendous disservice. With this speech, he’s fully exposing himself as a crank, and has thus reduced the ever-dwindling list of “credible skeptics” one further.

And in case anyone is curious, while the year-to-year variability is significant,  on climate-relevant timescales, sea level rise is indeed accelerating (Church and White 2011; Rahmstorf and Vermeer 2011).

But more to the point, absent emissions stabilization, sea level rise is going to increase, reaching 1m or more by end of century (Vermeer and Rahmstorf 2009).

Failure to stabilize emissions will almost assuredly result in the eventual collapse of the Greenland and Antarctic ice sheets, committing the world to multimeter sea level rise that will be for all practical purposes irreversible. Many of Ridley’s claims similarly depend on falsely equivocating between concern over future climate changes absent emissions stabilization (and their relative irreversibility over human timescales) and what is happening at present. This couldn’t be more misleading.

As you might imagine, given the way this is going, Ridley’s claim that methane isn’t increasing is also false. Methane levels today are much higher than they’ve been over at least the past 800,000 years and continue to increase (Loulergue et al., 2008; NOAA AGGI).

The “hockey stick” nonsense has been done to death. And “skeptics” like Ridley inevitably fail to mention the main points: the “hockey stick” has basically nothing to do with either the attribution of recent warming to humans or the seriousness of future warming; the ostensible statistical problems in the original Mann et al. paper were overstated by its critics, and the actual problems it did have don’t tremendously affect its results (Huybers 2005; Wahl and Amman 2007); moreover, independent Northern Hemisphere reconstructions (including “skeptics’” own) show more or less the same results as Mann et al.’s recent work- the warming during the instrumental record exceeds peak Medieval temperatures (Ljunqvist 2010; Loehle and McCulloch 2008; Mann et al., 2008; Moberg, et al., 2005).

People like Ridley spend an awful lot of time listening to “skeptic” bloggers like Jo Nova and Bishop Hill, but seem to have no grasp of basic Earth systems science. And it shows. There is a total lack of coherence in Ridley’s claims. Ridley wants us to know that the climate changed rapidly in the past- but yet we’re also supposed to believe that climate sensitivity is very small. He also flubs basic concepts- equilibrium sensitivity is not the same thing as transient sensitivity (i.e. how much we will warm in response to a given increase in radiative forcing is larger than how much warming we’ll experience in the near term due to things like the thermal inertia of the ocean).

Perhaps Ridley can follow his own advice and “unlearn” the lies, fallacies, and nonsense he’s being cheered for regurgitating. Though let’s just say I’m a little skeptical of the prospect.

References:

  • Church, J.A., and N.J. White (2011): Sea-Level Rise from the Late 19th to the Early 21st Century. Surveys In Geophysics, 32, 4-5, 585-602, doi:10.1007/s10712-011-9119-1.
  • Huybers, P. (2005): Comment on “Hockey sticks, principal components, and spurious significance” by S. McIntyre and R. McKitrick. Geophysical Research Letters, 32, L20705, doi:10.1029/2005GL023395.Ljungqvist, F.C. (2010): A new reconstruction of temperature variability in the extra-tropical northern hemisphere during the last two millennia. Geografiska Annaler: Series A, 92, 3, 339-351, doi:10.1111/j.1468-0459.2010.00399.x.
  • Loehle, C. and J.H. McCulloch (2008): Correction to: A 2000-Year Global Temperature Reconstruction Based on Non-Tree Ring Proxies. Energy + Environment, 19, 1, 93-100.
  • Loulergue, L., et al. (2008): Orbital and millennial-scale features of atmospheric CH4 over the past 800,000 years. Nature, 453, 383-386, doi:10.1038/nature06950.
  • Mann, M.E., et al. (2008): Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia. Proceedings of the National Academy of Sciences (USA), 105, 36, 13252-13257, doi:10.1073/pnas.0805721105.
  • Moberg, A., et al. (2005): Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data. Nature, 433, 613-617, doi:10.1038/nature03265.
  • NOAA AGGI: The NOAA Annual Greenhouse Gas Index. URL: http://www.esrl.noaa.gov/gmd/aggi/
  • Rahmstorf, S., and M. Vermmer (2011): Discussion of: “Houston, J.R. and Dean, R.G., 2011. Sea-Level Acceleration Based on U.S. Tide Gauges and Extensions of Previous Global-Gauge Analyses”. Journal of Coastal Research, 27, 4, 784–787, doi:10.2112/JCOASTRES-D-11-00082.1.
  • Vermeer, M., and S. Rahmstorf (2009): Global sea level linked to global temperature. Proceedings of the National Academy of Sciences (USA), 106, 51, 21527-21532, doi:10.1073/pnas.0907765106.
  • Wahl, E.R., and C.M. Ammann (2007): Robustness of the Mann, Bradley, Hughes reconstruction of surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence. Climatic Change, 85, 33-69, doi:10.1007/s10584-006-9105-7.

Roger Pielke Jr. just can’t help himself

At Keith Kloor’s a little while back, I tried to reach something of an amicable cease-fire with Roger Pielke, Jr. I decided to set aside his constant attacks on the scientists who blog at RealClimate in the interest of moving the discussion on mitigation options forward.

Roger, though, just can’t help himself.

Stefan Rahmstorf and Dim Coumou published an article in PNAS examining the influence of warming on the likelihood of extreme temp events, notably in the context of the blistering 2010 Russian heat wave. Roger accuses Rahmstorf of cherry-picking his period of analysis, and then uses this accusation to cast aspersions on the integrity of climate science more generally.

Here is another good example why I have come to view parts of the climate science research enterprise with a considerable degree of distrust.

Climate science — or at least some parts of it — seems to have devolved into an effort to generate media coverage and talking points for blogs, at the expense of actually adding to our scientific knowledge of the climate system. The new PNAS paper sure looks like a cherry pick to me.

What’s Roger’s actual complaint with the Rahmstorf and Coumou paper? Roger writes:

Look at the annotated figure above, which originally comes from an EGU poster by Dole et al. (programme here in PDF). It shows surface temperature anomalies in Russia dating back to 1880. I added in the green line which shows the date from which Rahmsdorf and Coumou decided to begin their analysis — 1911, immediately after an extended warm period and at the start of an extended cool period.

Obviously, any examination of statistics will depend upon the data that is included and not included. Why did Rahmsdorf and Coumou start with 1911? A century, 100 years, is a nice round number, but it does not have any privileged scientific meaning. Why did they not report the sensitivity of their results to choice of start date? There may indeed be very good scientific reasons why starting the analysis in 1911 makes the most sense and for the paper to not report the sensitivity of results to the start date. But the authors did not share that information with their readers. Hence, the decision looks arbitrary and to have influenced the results.

Roger obviously didn’t bother to actually read the paper he’s attacking.

If there’s one thing Roger can’t stand, it’s scientists pointing out that man-made global warming is making certain kinds of extreme events worse. If there’s another thing he can’t stand, it’s the scientists who blog at RealClimate. Put them together, and Roger goes off the deep end.

UPDATE:

Caught out, Roger is predictably moving the goal posts rather than acknowledging that his attacks were unjustified.

First Roger attacked Rahmstorf and Coumou for ignoring the pre-1911 data. He uses this ostensible sin of omission to smear the larger field. Except of course this is completely false. When this is pointed out, Roger moves the goalposts and claims that Rahmstorf and Coumou didn’t actually look at the 1880-2009 data because they didn’t use a linear trend to look at the 1880-2009 data. [Edited to add: this is an implicit rather than explicit claim by Roger, as we’ll see.] The paper is quite clear about making the case that the data (for 1911 on and for 1880-2009, for synthetic data and actual obs) are better described by a nonlinear trend, and the passage I cited in the original point makes it clear that the 1880-2009 data were analyzed using a nonlinear trend.

Roger then has the chutzpah to claim that Rahmstorf has “confirmed” Roger’s “critique”:

It would be quite shocking indeed if Rahmstorf actually “confirmed” Roger’s critique. But of course he did no such thing. When Roger claims “they did not run the analysis from 1880″, he’s completely wrong (see the above excerpt from the paper). When he claims Rahmstorf has “confirmed” his critique, what Roger really means is that Rahmstorf confirmed that they did not look at the 1880-2009 data using a linear trend- which, again is perfectly clear in the paper itself. So it has gone a bit like this:

Roger: “They didn’t look at the whole record!”

Uh, yes, they did.

Roger: “No, they didn’t perform The Analysis* for the whole record!”

*Valid only for Roger’s definition of “The Analysis”.

Roger has taken a concession that the paper did not do something it never claimed to have done and declared victory. Perhaps at some point he’ll realize that claiming something does not make it so.

FURTHER UPDATE:

Roger has repeatedly made the claim that Stefan Rahmstorf “confirmed” Roger’s critique. Roger’s original critique was that the 1880-1910 were not analyzed by Rahmstorf and Coumou. This original critique is patently false, as the paper shows in the excerpt I posted above.

The basis for Roger claiming that Rahmstorf “confirmed” his critique was Rahmstorf stating that a linear trend was not used in analyzing the 1880-2009, as is clear in the paper.

I let Rahmstorf know that Roger was claiming Rahmstorf confirmed Roger’s critique. Rahmstorf responded:

That is truly bizarre, since what I responded to Pielke (in full) was: “We did not try this for a linear trend 1880-2009. The data are not well described by a linear trend over this period.” As shown in the paper and above, our main conclusion regarding Moscow (the 80% probability) rests on our Monte Carlo simulations using a non-linear trend line, and of course is based on the full data period 1880-2009. Nowhere did we “use 1910-2009 trends as the basis for calculating 1880-2009 exceedence probabilities”, and I can’t think why doing this would make sense. Faced with this kind of libelous distortion I will not answer any further questions from Pielke now or in future. As an aside, our paper was reviewed not only by two climate experts but in addition by two statistics experts coming from other fields. If someone thinks that using a linear trend would have been preferable, that is fine with me – they should do it and publish the result in a journal. I doubt, though, whether after subtracting a linear trend the residual would fulfill the condition of being uncorrelated white noise, an important condition in this analysis.

And on a final note, Pielke actually had the nerve to write this:

You may read the paper differently than I do and you may interpret Rahmstorf’s comments differently than I do — happens all the time on these blogs. In such a situation I propose that the best course of action would be to solicit further information to resolve the dispute. Or, perhaps you’d rather we just make comments about motives and call each other names

This, after he wrote a post impugning the field over an “omission” that existed only in his mind. Unreal.

Initial thoughts on the Berkeley Earth Surface Temperature release

Image courtesy of Flickr user "crowderb", used under Creative Commons.

[First, congratulations to Robert Rohde, and the rest of the team that actually worked on the science end of the project. There are some outstanding issues that need to be resolved prior to calling the work a finished product, and I hope the BEST team addresses them.]

Was anyone outside of the “skeptic” blogosphere surprised by the findings that UHI, station quality, station drop out, etc. weren’t really affecting the surface record? I don’t think so. But there is a great deal of revisionist history going on, which I’ll get to in a moment. Speaking of revisionist history, though-

That Anthony Watts has done a complete 180 from his earlier pledge to accept the BEST results should surprise no one. His whining that the results have been released prior to review- given his entire “surface stations” project and his years of insinuating if not outright claiming that much of the instrumental warming was spurious- is the height of chutzpah. BEST is being transparent with their data and methodology, something that people (even WUWT regulars and “skeptic” true believers) fought tooth and nail to get Watts to do.

Roger Pielke Sr. was quick to attempt to downplay the BEST results by implying they were not independent of previous analyses. Perhaps Roger should have actually bothered to read the papers he was attacking. I guess it all depends what his goal was- to offer legitimate criticism, or provide Marc Morano with soundbites attacking BEST.

I agree with WMC that this changes basically nothing about my opinion of Muller himself. The charges that Muller grossly distorted the truth about the so-called “hockey stick” controversy, he doesn’t appear to really even understand basic aspects of climate science, etc. stand. My negative opinion of Muller stems not just from his current attempts to portray himself as single-highhandedly saving climate science from the “skeptics”, but go back to earlier encounters with him in paleo/geology literature. Let’s just say the dynamic of Muller trying to claim the mainstream has failed to account for something significant and Muller positioning himself as the tough truth-teller is nothing new. At least in this case Muller has the fortune of actually coming down on the correct side, something that can’t be said for his previous efforts.

Lastly, let’s talk for a moment about the furious backpedaling that’s happening in response to BEST. “Skeptics” over at Curry’s, WUWT, on social media sites like Reddit, etc. are falling all over themselves trying to claim that No True Skeptic actually denies that the Earth is warming. They’re claiming the BEST results are meaningless because they don’t actually address attribution.

To which I reply, “Bullshit.” A staggeringly large number of climate “skeptics” do in fact deny that the Earth is warming. A survey less than a month ago found that less than half (49%) of self-identified Republicans and even fewer (41%) self-identified Tea Partiers agreed that the Earth is actually warming.

No, the BEST papers do not directly address attribution, but neither did the myths that they (along with all the other analyses and data sets) exploded. Are we supposed to believe that “skeptics” weren’t claiming that all or much of the warming in the instrumental record was due to UHI, station siting, station drop out, etc.? Please.

If the “skeptics” want to pretend that they never claimed we weren’t warming as NASA GISS, Hadley-CRU, NOAA, et al. showed, and instead want to focus on the attribution of warming to human causes, so be it. I hope they don’t expect the rest of us to join them in their revisionism.

When the initial furor dies down, I’d like to discuss some of BEST’s interesting (as opposed to merely confirmatory) results.