Potential sea-level rise from Antarctic ice-sheet instability constrained by observations

20151115_163316 Catherine Ritz, Tamsin L. Edwards, Gaël Durand, Antony J. Payne, Vincent Peyaud & Richard C. A. Hindmarsh; Nature (2015) doi:10.1038/nature16147. And somewhat following on from Joan Crawford has risen from the grave! only its sane, well-crafted, and most important of all not only publishable but actually published. From the abstract:

Large parts of the Antarctic ice sheet lying on bedrock below sea level may be vulnerable to marine-ice-sheet instability… may be underway throughout the Amundsen Sea embayment… Physically plausible projections are challenging: numerical models with sufficient spatial resolution to simulate grounding-line processes have been too computationally expensive… and lower-resolution model projections rely on parameterizations that are only loosely constrained by present day changes. Here we project that the Antarctic ice sheet will contribute up to 30 cm sea-level equivalent by 2100 and 72 cm by 2200 (95% quantiles) where the ASE dominates. Our process-based, statistical approach… The dependence of sliding on basal friction is a key unknown: nonlinear relationships favour higher contributions. Results are conditional on assessments of MISI risk on the basis of projected triggers under the climate scenario A1B (ref. 9), although sensitivity to these is limited by theoretical and topographical constraints on the rate and extent of ice loss. We find that contributions are restricted by a combination of these constraints, calibration with success in simulating observed ASE losses, and low assessed risk in some basins. Our assessment suggests that upper-bound estimates from low-resolution models and physical arguments (up to a metre by 2100 and around one and a half by 2200) are implausible under current understanding of physical mechanisms and potential triggers.

Its saying that modelling is too hard, so lets try a more statistical approach; and if they do that, they get numbers that are, they believe, constrained to be smaller than some of the wilder estimates people have been flinging around.

The pic is the trees at Chatsworth edge.


* Batter my heart, three-person’d God
* Antarctica: ice gain or loss? by Jos Hagelaars, at Bart’s. Some explanatory words but no real conclusions 🙂

Economic losses from US hurricanes consistent with an influence from climate change

Perhaps not the world’s greatest shock in Nature Geoscience 8, 880–884 (2015) doi:10.1038/ngeo2560 by Francisco Estrada, W. J. Wouter Botzen & Richard S. J. Tol. Hmm, one of those names is strangely familiar.

There’s a press release from U Sussex: Professor Richard Tol is co-author… find that the upward trend in economic losses from hurricanes in the US cannot be explained by the commonly invoked increases in vulnerability and exposure… find that part of the trend cannot be explained by commonly used socioeconomic factors, but is consistent with an increase in the number and intensity of loss-generating cyclones that hit the US, possibly as a result of global warming. The authors estimate that US$2–14 billion of US hurricane losses incurred in 2005 may be attributable to climate change. Professor Tol said “Ha ha Pielke, stick that in your pipe and smoke it!” I may have made some of that up, but only a little bit. I’d tell you more but the b*st*rd thing is paywalled, so I don’t need to find a more convoluted excuse for not reading it.


* ISIS pledge to kill thousands of Americans by opening gun stores across the Midwest

Exxon: the Peabody analogy

Someone (I forget who; remind me and I’ll thank you) pointed me at Everything You Need to Know About the Exxon Climate Change Probe but were afraid to ask. That article makes some points I’ve already made (While environmental advocates have cheered Schneiderman’s effort to take energy firms to task over a global crisis, some legal scholars question whether he is the right man for the job. “You wonder why this is the sort of thing that a New York attorney general should be doing,” said James Fanto, a professor at Brooklyn Law School. “It seems like it’s just completely politically motivated.” Or perhaps “The big issue for Exxon here is what’s material,” said James C. Spindler, a business school and law school professor at the University of Texas-Austin. “Assuming they did have some research they didn’t disclose, that would be an omission,” although it might not be material if “the information is already out there” and available to investors. A question Schneiderman needs to answer, Spindler said, “is whether Exxon or other similarly situated energy companies are in a special position to have information that the rest of the world doesn’t.”

Anyway, its worth reading; I won’t quote it all. Another part I found interesting was On Sunday, meanwhile, Schneiderman reached a settlement with the largest U.S. coal miner, Peabody Energy. Which leads to Peabody Energy Resolves N.Y. Probe Into Climate Disclosures. And the settlement? That article says In a formal announcement of the agreement on Monday, Schneiderman said the company will file revised shareholder disclosures with the U.S. Securities and Exchange Commission and has agreed that all future statements to shareholders will be consistent with the terms of the accord.

Which must be pretty good news for them: no penalty, just a few revised statements. Who “won” depends on who is looking. Forbes says “Peabody, N.Y. Attorney General Reach Underwhelming Settlement On Climate Change Disclosures”: The world’s largest private-sector coal company has settled an eight-year-old dispute with the New York State Attorney General’s Office over its climate change disclosure practices by agreeing to what appear to be minor tweaks in how it will draft certain federal securities filings. Whereas Inside Climate News says “Peabody Settlement Shows Muscle of Law Now Aimed at Exxon”: Coal giant’s climate change settlement is ‘unprecedented first step’ in forcing honest disclosures from fossil fuel companies, NY attorney general says.

Which one is right? I’m with Forbes on this. Notice that ICN calls it a 2-year investigation, but Forbes thinks its 8. The Graun agrees with 8, as does Peabody’s press statement so I think it was 8.

And the message to Exxon? I can’t help but think this will cheer them up. The similarities are strong: the Graun even helpfully reminds me that Peabody has a history of telling porkies about GW too.

[Update: since everyone is pushing the tobacco analogy, I’m interested in examples. I haven’t seen any good ones yet. There’s an appallingly bad one at Curry’s which really shows how astonishingly low she has sunk -W]


* Freeman Essay #13: “The Nanny State” about the US legal settlement with tobacco companies at CH. Unsurprisingly, he’s against it.

More confusion from Hansen

Environment and Development Challenges: The Imperative of a Carbon Fee and Dividend says:

This chapter discusses the importance of a carbon fee and dividend in minimizing the impacts of climate change on humanity and nature. Before outlining the policies needed to produce a rapid phase-out of fossil fuel emissions, it enumerates the fundamental flaws of the Kyoto Protocol from the standpoint of climate science. One flaw is the “cap” mechanism, which purports to reduce carbon emissions at the rate required to stabilize climate but fails to provide universal price signals that would reward efforts to reduce emissions.

My bold. That’s not a flaw from the standpoint of climate science. Its an economic flaw. Does nobody proof read this stuff? This is like the sprawling unpublishable ice melt paper: there’s no-one who can say to Hansen No; just don’t do it this way. Also, it would be nice if he could bear to call his “fee” system a carbon tax. The problem with doing that, though, is he then has no ideas to bring to the party; we’re back to standard mainstream economics. As for It also explains how
such an approach may be implemented both nationally and internationally
I find it hard to believe he has anything very useful to say, but very easy to believe that he hasn’t bothered read the literature.

Study Finds Controlled Washington, D.C. Wildfires Crucial For Restoring Healthy Political Environment

Says The Onion.

And its right, even if the original is damaged (I’ve not done it, of course)). But that’s not quite what I wanted to write about…

I wanted to talk about The war against Exxon Mobil (WaPo) and the contrast between reactions to that and In re Smith v Karl (and several reprints).

mt’s article is easy for all right-thinking people to agree with. So much so that mt even found one wrong-thinking person who also agreed with it (that’s a joke; don’t get all huffy).

But what about the obvious obverse, which is the witch hunt against Exxon? I asked mt about that and that, oooh, it turned out to be a tricky question for mt (though not for TF, obviously, who easily maintains the same stance as he managed to apply to irSvK). Definitely no condemnation forthcoming; the closest was “I don’t understand anyone claiming that what Exxon was doing, flirting with the edge of fraud on their communication on climate, wasn’t transparently obvious all along”. And some assertions that its all pretty well similar to the fag companies, and everyone hates them, don’t they? Well, everyone right thinking of course. And the people collecting taxes from the products they sell, of course.

[Update: mt has a long piece agonising about this; I don’t agree with his conclusions but his words are worth reading. His shorter version has a title “Investigate Exxon, but Blame Yourself” that is good enough to agree with. Though I could wish he’d expanded on the second half in his piece; I’ve made that point, I’ll argue, though I can’t now find where -W]

The “investigation” of Exxon looks very much politically motivated to me. We don’t know what you’ve done wrong but we’d like to see an enormous pile of internal emails please. Remind you of anything? Of course: in re Smith vs Karl. But if you’ve got nothing to hide, surely you’d be happy to turn over your emails? Well, no, that’s not true, as we can all immeadiately see when applied to anything on “our side”. But you must turn over your emails, because we think if we look though them all we might find something wrong. Well no, see irSvK. But Exxon were being naughty and funding disinformation. Yes and anyone who cared knew about that ages ago when they were actually doing it. And people pointed out, in public, that they were doing it. It was not a secret.


* Exxon speaks
* A Range of Opinions on Climate Change at Exxon Mobil (NYT)
* Why The Investigation Of ExxonMobil Matters – UCS
* The House Committee on Science and Intimidation – Raymond S. Bradley in HuffPo

Deepak Chopra vs Wikipedia

484356_513411482057123_169470915_n Slightly not-the-usual fare, but H mentioned it and its wiki, and following – or failing to follow – the trail was moderately amusing, so here we go. Deepak Chopra is an Indian American author and public speaker.[4][5] He is an alternative medicine advocate and a promoter of popular forms of spirituality, but more importantly is the winner of an 1998 IgNoble prize for his unique interpretation of quantum physics as it applies to life, liberty, and the pursuit of economic happiness. [REFERENCE: Deepak Chopra’s books “Quantum Healing,” “Ageless Body, Timeless Mind,” etc.] Or as wiki puts it,

The ideas he promotes are criticized by scientists and medical professionals[14] who say that his treatments rely on the placebo effect,[8] that he misuses terms and ideas from quantum physics (quantum mysticism), and that he provides people with false hope which obscures the possibility of effective medical treatment.[15] The medical and scientific communities’ opinion of him ranges from dismissive to damning; criticism includes statements that his approach could lure sick people away from effective treatments.[14]

Not unnaturally, he’d rather wiki didn’t put it that way; and with an income one ~8M$/yr (he “charges $25,000 per lecture performance, where he spouts a few platitudes and gives spiritual advice while warning against the ill effects of materialism”) he’ll find people to speak for him. And so we find the Huffpo finding space for Wikipedia and Deepak Chopra: Open-Source Character Assassination by “Ryan Castle”, of whom more anon. Curiously, that piece doesn’t mention Wikipedia, A New Perspective on an Old Problem by DC, also at Huffpo.

I won’t trouble you with what’s in those Huffpo articles, because they aren’t interesting – they’re the kind of things you’d expect AW to write about wiki’s articles on GW, or on himself; there’s even the traditional list of “eminent” “experts” who agree. More amusing is to try to backtrack down the wiki-trail.

Unexpectedly, DC himself offers a clue, because he says “Websites such as ‘Wikipedia, we have a problem’ offer…” and on that site I find How Wikipedia Editor Manul Outed My Identity, Stalked And Hounded Me On Wikipedia. Its written by “Rome Viharo” who tells us that he was “outed” when he posted this edit which is signed by “[[User:Tumbleman|Rome Viharo]]”. Tumbleman / Rome Vihario has an odd editing history; first appearing before 2006, but making no edits after 2009-06-08T20:04:36 until that aforementioned edit at 2013-08-31T20:02:26 to the Sheldrake (say no more) talk page; which is then followed in a very short space of time by lots of other edits to the Sheldrake talk page. Unwisely, RV tells me he has a RationalWiki page and that makes the situation somewhat clearer. T/RV was blocked for a week for socking starting 2013-10-13T20:23:46, and then indeffed at 2013-10-17T13:22:37 for being a general waste of time / troll.

Now, back to “Ryan Castle”. Wiki has no such editor, and yet “Ryan Castle” claims “long experience as a Wikipedia editor”. The obvious suspicion is that “Ryan Castle” is the same as RV [Update: a person who I have no reason not to believe is RV has posted a long comment, in part of which he says he and RC are different people]. I suggested this on wiki but didn’t get a bite. If you can do better than my semi-autistic ability to recognise faces, tell me if this, RC looks like this, TEDx. The Huffpo bio, presumably self-provided, of RC says “Ryan Caste is the founder and executive director of ISHAR”. But RV says “I can also confirm that I hired Ryan Castle to be an archivist for the ISHAR project” (in a post that deals in part with how RV was kicked out from being CEO of ISHAR). Its not clear how those two fit together, unless we’re looking at a Stalinist-style airbrushing.

[Update: assuming we believe the RV in the comments, then “Ryan Castle” is [[User:Askahrc]] who signs as “The Cap’n”. And given that an early version of his talk page signs himself Ryan, that seems rather likely.]

Mass gains of the Antarctic ice sheet exceed losses?

[RealClimate has a post with more useful detail.]

I last commented about Antarctica and SLR when I “reviewed” the AR5 cryosphere chapter. As I noted there, things have come on quite a way since I were a lad (2005, 2004) and the major advance looks to be GRACE, even if they sometimes recalibrate their isostatic rebound; see-also this from 2009. And now, via Sou, I find Mass gains of the Antarctic ice sheet exceed losses by Zwally et al. Which says

Mass changes of the Antarctic ice sheet impact sea-level rise as climate changes, but recent rates have been uncertain. Ice, Cloud and land Elevation Satellite (ICESat) data (2003–08) show mass gains from snow accumulation exceeded discharge losses by 82 ± 25 Gt a–1, reducing global sea-level rise by 0.23 mm a–1…

This contradicts the aforementioned AR5, which says

Overall, there is high confidence that the Antarctic ice sheet is currently losing mass. The average ice mass change to Antarctica from the present assessment has been –97 [–135 to –58] Gt yr–1 (a sea level equivalent of 0.27 mm yr–1 [0.37 to 0.16] mm yr–1) over the period 1993–2010, and –147 [–221 to –74] Gt yr–1 (0.41 [0.61 to 0.20] mm yr–1) over the period 2005–2010. These assessments include the Antarctic peripheral glaciers

And you can if you wish see what that is based on:

And you can’t really fix the discrepancy by quibbling about the exact time period used, either. Again from AR5:

Or see-also figure 4.16. So, how do Zwally et al. resolve the discrepancy, which is almost entirely over East Antartica? Because it really is up to them to do the resolution. Not entirely convincingly I’d say:

A likely cause for the lower GR estimate is the sensitivity of the GR estimates to the glacial isostatic adjustment (GIA) correction, as discussed in the Appendix where we note that a –1.6 mm a–1 change in the modeled dB/dt would bring the GR and our dM/dt into agreement…

Which seems to amount to, if we change some numbers we could get a different answer. But if we change some of Zwally’s numbers, we could also get a different answer. FWIW, I’d trust GRACE more than anything else; it just feels intrinsically more reliable.

However, in at least one sense, none of this matters. What we care about above all else is the change in the mass budget of Antarctica, because that feeds into changes in the rate of SLR. After all, we already know the current rate of sea level rise. If Z is right about East Antarctic and that is actually gaining mass, all it means is that somewhere else is losing more mass than we thought. East Antarctic is probably least interesting for changes in mass balance because, whilst huge (~50 m of SLR in total, as against ~5 for West Antarctica of Greenland; those numbers are all for total melt, which won’t happen soon for any of them) its very slow; Greenland, the Antarctic Peninsula or West Antarctica are more interesting for change.

Note: the comments chez Sou are worth reading; in particular the note about Cryosat, and the link to Gavin’s perceptive and meticulous analysis of the relative merits of Zwally vs GRACE, which pretty well amounts to my meh, I’d trust GRACE more. Though I’m sure he could expand on that at greater length if given the chance. Oh, if only he had his own blog :-).