climate science
stoat | August 30, 2007Two sources point me towards a Neville Nicholls letter about a 35 year old paper by Sawyer, but Inel gets the hat tip. Nicholls uses the paper to demonstrate that concern about GW is nothing new (it also blows the "everyone was predicting a new ice age in the 70's" away, but thats another story), and he considers Sawyers about-right prediction of 0.6 oC T rise by 2000 as "perhaps the most remarkable long-range forecast ever made". I suspect it doesn't have much competition (any proposals?) but how does the Sawyer paper actually read?
Curiously enough, I had cause to be flipping through 70's…
stoat | August 20, 2007RC laid into tipping points a while back but now they are back in fashion, it seems: via Tim Lenton, reported at RC today. But they seem as vague and ill-defined as ever.
I still retain my antipathy to the idea. TL has now switched from "tipping points" to "tipping elements" to describe the components of the Earth system that can be switched - under particular conditions - into a qualitatively different state by small perturbations. This is broad and vague, but he produces a longer but also very broad and vague definition later in his article. He wants to include slow changes "analogous to…
stoat | August 19, 2007JA has a nice entry on Schwartz' sensitivity estimate pointing out where the probable errors are.
I too found the 5-y timescale rather low. Fitting in with James's assessment that S is wandering out of his field, I was surprised by the lack of discussion of how this new result fits in with everyone else's answers. There is a brief note that "This climate sensitivity is much lower than current estimates, e.g., the Fourth Assessment Report of the Intergovernmental Panel on Climate Change..." but that seems to be about it.
Meanwhile, Irreducible imprecision in atmospheric and oceanic…
stoat | August 11, 2007Doug Smith and colleagues have a new paper in Science Improved Surface Temperature Prediction for the Coming Decade from a Global Climate Model. The abstract is Previous climate model projections of climate change accounted for external forcing from natural and anthropogenic sources but did not attempt to predict internally generated natural variability. We present a new modeling system that predicts both internal variability and externally forced changes and hence forecasts surface temperature with substantially improved skill throughout a decade, both globally and in many regions. Our…
stoat | August 9, 2007Via Lubos (sorry: I was looking for rumours of him leaving) I find some interesting stuff re the temperature record it China.
Lubos has misunderstood and oversold it, but the original makes for strong and interesting reading. Mind you SPM fig 4 makes it rather unlikely that any major change to the temperature record is going to be needed.
stoat | July 12, 2007The egregious Soon has a paper, Variable solar irradiance as a plausible agent for multidecadal variations in the Arctic-wide surface air temperature record of the past 130 years which is a weasel-worded title if ever I saw one. But anyway: Soon is comparing the "Arctic" temperature record to the solar irradiance (via some proxy or another) and finding a wonderful match, which sends the Durkins of the world into a frenzy. Of course, this means that the solar *doesn't* match the global record; and of course given almost any shape of solar you could find some region of the world whose…
stoat | July 10, 2007You couldn't get a more perfect example of desperation than:
At the recent International Symposium on "Landform - structure, evolution, process control", University of Bonn, Germany, June 7-10, 2007, that I attended, there was evidence presented of the retreat of all of the glaciers in the Alps. However, thanks to CCNet and Benny Peiser for alerting me to a paper which provides evidence that one glacial area in these mountains is not retreating. [1] [2]
And the one area that isn't retreating? That is also very revealing: its the highest glaciers. And why aren't they retreating? For the…
stoat | July 5, 2007Very little other than the bleedin' obvious I fear. Inel laments her lack of access; but http://blog.petedecarlo.com/ has read it and provides a copy of the Nature comment, but not the Proc Royal Soc original. Not having read the original, I'm not sure what was in it worthy of publication; the lack of a trend in solar is known already. But the septics are rather like Monty Pythons Balck Knight: no matter how many limbs you chop off they hop around on one leg or offer to bite your shins, and they need to be stomped on every now an again.
Even if you're mad enough to insist that solar forcing…
stoat | July 5, 2007I'd just like to let you know that the weather here has been pretty rubbishy for what seems like ages. Down here we're not getting the floods they have oop north, just lots of rain, and indeed yesterday some hail too.
This has a vaguely serious side. Clearly, one summer (or lack thereof) doesn't make for a trend; but its one answer to those who say "global warming; oh good Blackpool will be like the french riviera". It might just get warmer; but more likely weather patterns will shift; and who knows it could shift to excess summer rain.
stoat | July 2, 2007Another interesting entry on the often-provoking RP Sr site. This time a guest post by McNider, who I don't know. He indulges in some giveaway ranting: Climate change alarmists have used the global surface temperature record as evidence of man's impact on climate being "real" yet, as discussed below, most of the warming in this record is at night and probably has little to do with the accumulation of heat in the atmosphere which is foolish, unless you want to dismiss the IPCC as alarmists, which leaves you amongst the wild-eyed Lubos fringe. And requires you to believe some strange things…
stoat | July 1, 2007So says the Chicago Sun-Times. Oh dear. But what are these claims? For example, Gore claims that Himalayan glaciers are shrinking and global warming is to blame. Does he? I suppose he might, though I don't remember it myself. Whats the rebuttal? Yet the September 2006 issue of the American Meteorological Society's Journal of Climate reported, "Glaciers are growing in the Himalayan Mountains, confounding global warming alarmists who recently claimed the glaciers were shrinking and that global warming was to blame." Curious language for J Climate, no? Makes one suspicious. No ref, of course.…
stoat | June 26, 2007Gosh this is fun... you wait ages for a paper on a warm event and then 2 come along together :-).
Anyway, thanks to FB for pointing out How unusual was autumn 2006 in Europe? in Climate of the Past. This is almost but not quite the same thing as the 2003 event so I had all the code ready and submitted a little comment. Since its on-line open access you can see it, just click on the interactive discussion.
Looking in the Chase et al. style hemispheric context, 2006 doesn't look so unusual, even when looking at T1.5m.
stoat | June 22, 2007Asks RP Sr's paper in GRL (or rather, ask Thomas N. Chase, Klaus Wolter, Roger A. Pielke Sr and Ichtiaque Rasool). Interestingly, they conclude "not really". This of course is contrary to what everyone knows, so their paper has been ignored, to RP's annoyance. And if I had demonstrasted conclusively that a well known thing was wrong, and everyone just steamed ahead and ignored this inconventient fact, I'd be annoyed too. But has he indeed demonstrated this?
I thought I'd have a closer look at the data.
Their main result is that the fraction of the globe (or rather, the fraction of 22N to 80N…
stoat | June 18, 2007Not quite "we're all going to die" again, but close. But this time by James Hansen, and published in Proceedings of the Royal Society.There is an the Indescribably-over-hypeded write up of it. Featuring:
nothing short of a planetary rescue will save it from the environmental cataclysm of dangerous climate change. Those are not the words of eco-warriors but the considered opinion of a group of eminent scientists writing in a peer-reviewed scientific journal.
Diversion: the article has a side bar pointing to Earth in peril: Climate change brings early spring in the Arctic which is a prime…
stoat | June 18, 2007Prompted by a fight at wikipedia over whether PC is an astrophysicist, a meterologist, a meterological consultant, or something else, I looked at "weather action"s website for his proofs of success (ah, for those who don't know, PC claims to predict UK weather a year or so in advance via a "solar weather" technique whose details are obscure, since he won't publish them. The solar-weather link is unclear, as indeed is his method of predicting solar a year in advance. It makes him inclined to disbelieve CO2-GW (since its all solar, guv) and he got into TGGWS confusing weather and climate).
And…
stoat | June 17, 2007Nature has a brief report on a PNAS paper, "Transient climate-carbon simulations of planetary geoengineering" by H. Damon Matthews and Ken Caldeira. BTW, before I get going, look at the sidebar on the right of PNAS - there is a "google scolar" search link built in. The abstract is:
Geoengineering (the intentional modification of Earth's climate) has been proposed as a means of reducing CO2-induced climate warming while greenhouse gas emissions continue. Most proposals involve managing incoming solar radiation such that future greenhouse gas forcing is counteracted by reduced solar forcing. In…
stoat | June 7, 2007Old man in a cave has a nice post on the US CCSP draft document out on its website; Climate Models - an Assessment of Strengths and Limitations for User Applications. I've just scanned the exec summary and didn't see any surprises. Hopefully they found something more interesting to say in the main text.
stoat | May 25, 2007A while back I noted a paper in CPD that questionned the "there is an 800 year lag of CO2 at deglaciations" meme which has become such a favourite of the septics recently (most people go with the "yes its true but irrelevant", but the maybe its not true is also possible). When I noted the paper before it was just submitted.
Now its had two reviews and an editor comment by the sagacious Eric Wolff, and to my eye it seems to have survived largely unscathed. Indeed the reviewers call for it to consider the consequences rather more, so there maybe interesting times ahead for the idea.
stoat | May 24, 2007Kevin Vrames at Climate feedback has a nice post on a perverse-incentive problem with one part of the CDM. Which is one small part of the reason I don't buy any offsetting at the moment.
stoat | May 17, 20075 year trends from surface temperature are not very significant and are a bad measure of anything. As everyone should know. But it seems that some people don't. So in tedious detail...
Pick up the HadCRU temperature series from here. Compute 5, 10 and 15 year trends running along the data since 1970 and get (black lines data, thicker black same but smoothed, thin straight lines non-sig trends; thick straight blue lines sig trends):
From which you can see (I hope) that the series is definitely going up; that 15 year trends are pretty well all sig and all about the same; that about 1/2 the 10…