Cooling-gate: the 100 years of warming Easterbrook wants you to ignore

by Gareth on May 27, 2010

Evidence that Don Easterbrook did more than misrepresent and alter a graph in order to remove evidence of recent warming in his presentation to the recent Heartland “climate conference” is beginning to emerge. It now appears that he has been misusing one of the most important paleoclimate temperature data series, compiled from the GISP2 Greenland ice core, effectively hiding a full 100 years of recent warming. His “rebuttal” of my revelations that he had misused a graph from Global Warming Art includes this assertion:

…below is the Greenland data for the past 10,000 years (Holocene) from the published paper by Cuffy and Clow (1997), two distinguished US scientists. Note that temperatures for almost all of the past 10,000 years have been warmer than present.

In my post yesterday, I suggested (on the basis of the notes accompanying the raw δ18O data), that the “present” Easterbrook was referring to was 1950. It now appears I was being far too generous. Thanks to a bit of detective work by MartinM in the comments to that post, the data set used by Easterbrook to draw his version of a Holocene temperature graph turns out to be the temperature series derived from the δ18O data by Richard Alley: Alley, R.B. 2004. GISP2 Ice Core Temperature and Accumulation Data. IGBP PAGES/World Data Center for Paleoclimatology
Data Contribution Series #2004-013. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA
(ftp download here). The most recent temperature data point in that series is 1905, and that’s the point Easterbrook labels as the present. To make his case he has to make a full century’s worth of warming disappear.

 

I downloaded Alley’s data and plotted it with my new favourite graphing tool. This is what it looks like:

GISP2graph

I’ve inset the graph from Easterbrook’s “rebuttal”, and added a couple of helpful lines (click for a bigger version). I think it’s pretty clear that the data behind both graphs is the same. There’s more detail in my plot, but the key features are all in the right places. I’ve added a blue line to represent Easterbrook’s “present temperature”. The green line represents an estimate of current temperatures in central Greenland. I looked at the nearest station with a 100+ year record in the GISS database (Angmagssalik), and used a Mk 1 eyeball to estimate a 2.5ºC increase over the century (I’d welcome a more accurate estimate, if anyone’s prepared to dig one up). The difference between the green and blue lines is the warming that Easterbrook wants to ignore. His statement that temperatures for almost all of the past 10,000 years have been warmer than present is shown to be complete nonsense. There are three points in the last 10,000 years when temperatures high up on the Greenland ice sheet were similar to today, but by no stretch of anyone’s imagination can it be said to have been warmer for most of the time. The incline he’s trying to hide is one of the largest and steepest in the last ten millenia…

The same temperature series also appears to form the basis for Monckton’s famous “Curry & Clow” slide from early 2009:

Monckton credits the wrong people, of course, but adds a helpful “300 years of warming” arrow. Like Easterbrook, he omits the last 100 years of warming. This is what he said at the time:

Seen in the geological perspective of the last 17,000 years, the 300 years of recent warming, nearly all of which must have been natural, for we could not have had any significant influence except in the past 25 years, are manifestly insignificant.

The 300 years of recent warming are of course the 300 years up to 1905. What has happened since then is manifestly significant. This sort of misdirection is par for the course for Monckton, but what about Easterbrook?

If he knowingly misrepresented 1905 as the “present” (and given that he claims to have “the entire Greenland oxygen isotope data in my computer and use it extensively to plot data” that has to be a real possibility), then he is clearly misusing the data and misleading his audience. The intellectual dishonesty involved is breathtaking. His audience may want to be mislead, but that is irrelevant. On the other hand if, as a distinguished academic with a long career studying (amongst other things) glaciers and climate change, he really doesn’t know that the data series stops in 1905, then he is demonstrating ignorance of a sort that would embarrass any student.

So where’s the investigation of this academic fraud? Where are the hordes of bloggers and journalists screaming blue murder about the manipulation of data to tell a convenient story? Here’s Joseph Bast, president of the Heartland Institute, writing about the so-called “climategate” affair last November:

Looking at how past disclosures of fraud in the global warming debate have been dismissed or ignored by the mainstream media leads me to suspect they will try to sweep this, too, under the rug. But thanks to the Internet, millions of people will be able to read the emails themselves and make up their own minds. This incident, then, will not be forgotten. The journalists who attempt to spin it away and the politicians who try to ignore it will further damage their own credibility, and perhaps see their careers shortened as a consequence.

How very true. I look forward to Bast issuing a statement apologising for being a party to Easterbrook’s fraud, for providing him with a platform to mislead and misinform, and instituting an in-depth investigation into the background of Cooling-gate. But I suspect he will be doing his best to ignore the whole affair. I leave it to the reader to decide what that does for the credibility of Bast, Heartland, and the scientists who shared a stage with Easterbrook at Heartland’s Chicago conference.

[Update 29/5: My graph revised and improved, see comment below]

{ 51 comments… read them below or add one }

Scott Mandia May 27, 2010 at 3:23 am

So what do you think his motives are? He does not appear to be linked to any CTTs or other front groups. Checked Sourcewatch and ExxonSecrets and not much comes up. Is he just trying to get some limelight?

Scott A. Mandia, Professor of Physical Sciences
Selden, NY
Global Warming: Man or Myth?
My Global Warming Blog
Twitter: AGW_Prof
"Global Warming Fact of the Day" Facebook Group

Rob Taylor May 27, 2010 at 5:31 am

Or perhaps some extra cash to ease his twilight years?

Gareth May 27, 2010 at 5:52 pm

His home page (under the "glaciers and climate change" link above) mentions a 2001 paper which seems to have been proposing cooling coming soon. I suspect that he adopted this position a long time ago, and is clinging to it. It's his point of difference, perhaps, in sceptic circles. "Ah, Don, he's the cooling coming soon guy — always good for a pithy talk". Adds to the noise. Doesn't matter that's he's talking nonsense.

bill May 27, 2010 at 10:00 am

Current notoriety is more important than posterity? Simple inability to back down? Does he despise Greenies? I could name another well-known Geologist for whom that's a deep, deep motivation.

In his rebuttal he insisted there really is evidence of the global-cooling induced famines he's been predicting! At the end of the warmest decade on record that's one hell of an achievement! Since it's unlikely we're going to get back to the same temps as those that prevailed during the bulk of the 20th Century anytime soon – no matter how hard the trends get recalculated [thanks Hank!] – we can only logically conclude that cold-induced global famine must have been a way of life through to, oh, the late 80s? Funny I didn't notice!…

This is a position beyond the reach of satire. So, just as Gareth has demonstrated above with the rhyming graphs, sadly comparisons with paranoiac fabulists like Monckton become hard to avoid.

Scott Mandia May 27, 2010 at 11:31 am

Maybe we have the Duesberg Effect here. Duesberg is an award-winning cancer researcher who believes bad lifestyle choices and not HIV is the cause of AIDS and he has never backed away from that position. I guess for some scientists, being wrong is not an option. Odd, because scientific method can only function when we are also wrong.

TrueSceptic May 27, 2010 at 1:00 pm

There are many AGW "sceptics" who appear to be not financially motivated. IMO this is all about ideology. They simply cannot believe that we can alter the planet's atmosphere enough to alter the climate as this would conflict with their right/libertarian beliefs in "freedom", the "freedom" of both individuals and societies to exploit the planet's resources as we wish without consequence.

Once someone believes so strongly in something like this, they are beyond rational argument, no matter how able they might be in other fields. It can only be compared with religious belief, which often involves acceptance of extraordinary claims without question.

Scott Mandia May 28, 2010 at 3:45 am

The ideology angle is an interesting one and I suspect that Christy and Spencer fall into the religious part of that – both are devout Christians. In fact, Spencer is pro-Intelligent Design which is totally at odds with the scientific method.

Anyway, if you take a look at reason three in my Three Major Reasons Why There is So Much Misinformation you will find an interesting study that shows that individuals subconsciously resist factual information that threatens their defining values.

After reading that I posted How to Talk to a Conservative about Climate Change that frames the impacts of climate change using a conservative world view. (I also have this as a blog post.)

I am curious what you all think about this tactic?

Gareth May 27, 2010 at 11:42 pm

I have friends and neighbours I would describe as "traditional conservatives". In NZ, that means on the right of the political spectrum, but not ideologues. Instinctively distrustful of "greenies" or anything that might raise taxes. They're not well-informed on climate – it's a non-issue, a green thing – so they respond well to calls to ditch the ETS. Most of them have strong ties to the land, either as farmers or as landowners.

Conversations are rarely fruitful. I usually try to explain that the politics should be in the response, not in the definition of the problem, and that if they deny the existence of the problem they deny themselves a seat at the table when solutions are being sought. There's a need for a right wing voice to be heard — which is exactly what Scott Denning said at the Heartland conference. Some respond well to this line of argument, the more closed-minded don't.

When I talk to my friends and neighbours who are winemakers, I get a totally different response. They are either already seeing the impacts of climate changes on winegrowing, or are aware of the impacts overseas. There's a wide spectrum of opinion on how serious the problem actually is, but at least the door's open…

Glacier Guy June 1, 2010 at 5:21 pm

I am fairly certain Easterbrook's motivation isn't political, ideological, or financial (he's apparently well off enough to donate a substantial endowment to the Geol. Soc. of America for a research award in his name, so he doesn't need money). Having heard him speak, and talked to others, his primary motivation seems to be ego, and the sense that he's never gotten the scientific recognition he seems to think he deserves. If you read his email to Mauri Pelto in Gareth's recent post on "caught red handed," note that Easterbrook states that he started measuring mass-balance on Mt. Baker glaciers well ahead of Mauri (he didn't…one of his students did some work on it, which he takes credit for, but not with field measurements like Mauri has). Easterbrook's territorial instincts appear to be driven by a rather enormous need to "own" an area scientifically (i.e., ego).

Hank Roberts May 28, 2010 at 2:51 am

> motives
We don't even know for sure what data he used, or whether he produced those two graphs himself.
Remember people do get old, and trust too much, and get fooled about what they put their names on.
It's possible he asked someone to make up a graphic and told them what to use and trusted the result. We simply can't know unless he (sigh) shows or points to the data set, the actual numbers. Since his answer was that he had them on his own computer, there's no way to check what happened, let alone what his motives were.

Remember the Revelle/Singer story:
http://www.loe.org/shows/shows.htm?programID=94-P
http://rabett.blogspot.com/2007/04/if-richard-lin
http://scienceblogs.com/stoat/2007/11/the_real_tr

My guess, this is a 'picador' story (or a 'rodeo clown' if you prefer the norteamericano sport) — someone who's thrown into the ring to distract attention when there's some problem. It makes me curious what else was wrong in the stuff Heartland put up, more than curious about this stuff.

Rob Taylor May 27, 2010 at 3:32 am

ROFL, dear Roger Dewhurst and Steve Wrathall…

"Your credibility has run out. The shit has hit the fan and there is NOTHING you can do about that except hide under the bed and cry."

Or are you two also hiding out in 1905?

ROFL

Richard T May 27, 2010 at 3:51 am

Just confirms what I knew already knew about the deniers intellectual dishonesty, but what's with the crown and portcullis?

Lotharsson May 27, 2010 at 5:05 am

"…what's with the crown and portcullis?"

Monckton uses that a lot, presumably because it's quite similar to the British House of Lords insignia (which he has been officially told not to use), and because he's partial to implying to the uninitiated that he's a member of the House of Lords (presumably to try and garner credibility with certain segments of the audience).

He's not a member – he's a hereditary peer, but that does not entitle him to a seat in the House. He did run for a seat once, but received (IIRC) no votes.

ctg May 27, 2010 at 11:45 am

One cannot run for election to the House of Lords, so I presume you are referring to His Lordship's recent attempt to run for the House of Commons? He did register as a PPC, but withdrew before the election.

He is not, and never has been, a member of either House. He has absolutely no entitlement to use the Houses of Parliament logo, of which his portcullis logo is clearly a rip-off. Nor did he have any entitlement to describe himself as a "representative of the United Kingdom legislature", as he did when presenting himself to the US Congress when testifying on climate matters.

I call that particular fiasco "Lord Gate", which along with "Cooling Gate", "ENSO Gate" and various others paint a rather bleak picture for the skeptics of late.

TrueSceptic May 27, 2010 at 12:25 pm

Munchkingate.

bbickmore May 27, 2010 at 7:44 pm

After the House of Lords Act 1999 passed, only 92 hereditary peers are still members of the House of Lords. (The other members are "Life Peers" whose titles are not passed on to their children.) When one of the 92 relinquishes a seat (by dying, or whatever) a special election is held, in which members of the House of Lords belonging to the party of the deceased can vote on whom they want to replace him. Monckton has run for an open seat in the House of Lords more than once, and has never received a single vote.

He recently aborted a planned run for the House of Commons, which is interesting because members of the House of Lords are specifically prohibited from running for the House of Commons.

If you want to see everything you need to whack Monckton over the head with this issue anytime he pops it out of his snake hole, see the following pages:
http://bbickmore.wordpress.com/2010/05/06/dance-m
http://home.comcast.net/~bbickmore/Climate/KingOf

Bernard J. May 28, 2010 at 4:14 am

After the election several weeks ago there is an expectation of electoral reform in Britain, which could possibly include introducing elections to the House of Lords. A long bow to draw, I suspect, but apparenlty it's on the agenda:
http://www.abc.net.au/rn/latenightlive/stories/20

Monckton must be salivating at the thought…

bill May 27, 2010 at 12:11 pm

You're quite correct. No votes.

The official line according to the House of Lords Information Office –

Christopher Monckton is not and has never been a Member of the House of Lords. There is no such thing as a "non-voting" or "honorary" member.

So they won't let him in despite his possessing the (pre-requisite?) capacity for abrasive, pompous windbaggery in spades –

Finally, you may wonder why it is that a member of the Upper House of the United Kingdom legislature, wholly unconnected with and unpaid by the corporation that is the victim of your lamentable letter, should take the unusual step of calling upon you as members of the Upper House of the United States legislature either to withdraw what you have written or resign your sinecures.

In the circumstances, your comparison of Exxon's funding of sceptical scientists and groups with the former antics of the tobacco industry is unjustifiable and unworthy of any credible elected representatives. Either withdraw that monstrous comparison forthwith, or resign so as not to pollute the office you hold.

(These nasty Congressional types; imagine questioning the motives of Exxon!)

This from a man who's pretending to be part of the British Government. But, after all, nobody can demand that he resign!

Barry Bickmore's piece on Monckton is a hoot, incidentally.

bill May 27, 2010 at 11:07 pm

Just spotted this (via Climate Progress): John Abraham's systematic and devastating demolition of perhaps the most (in)famous entertainer the House of Lords never produced –

Chris Monckton – 'how easy it is to fabricate Data'

Worth your time! He goes to all the sources Monckton cites, and what do they say? "CM don't know what he's talking about." Astonishing, isn't it?

Fans of the MWP, warmth-loving polar bears, no ocean acidification, ice expanding in the Arctic, etc. prepare for yet another bad day! (I suspect you're not going to enjoy the coming decade, either… why not just quit while you're not ahead?)

dappledwater May 27, 2010 at 11:06 am

"He did run for a seat once, but received (IIRC) no votes." – Lotharsson

Yeah, even Monckton knows better than for vote for himself.

TrueSceptic May 27, 2010 at 12:40 pm

Could someone clarify something? Easterbrook's slide 4 is about Greenland and is marked as such. Is he claiming that this represents global temperature changes over the same period, or just using it as an example?

Glacier Guy May 27, 2010 at 10:59 pm

Yes, he infers that it's a record (and the Best record too) of global temperature (and I think he actually believes it, having been to several of his talks and heard his response to just that question). He seems to confuse the local record of temperature at Greenland Summit, with the global record of CO2 (and Methane, and other gases) preserved in the bubbles of the same ice. He really doesn't seem to understand that 18O/16O in the ice at Summit is NOT a global average.

MartinM May 27, 2010 at 1:36 pm

Some additional support for your estimate of current Greenland temps can be found in this paper, which uses data from several automatic weather stations near the GISP2 location to produce a record for the period 1987-1999. Figure 9 shows their reconstruction, which appears to have a mean of roughly 244K for that period, which matches quite nicely with your estimate.

Incidentally, it seems that Easterbrook has been misrepresenting (and misspelling) Cuffey and Clow for at least a year and a half.

Gareth May 27, 2010 at 11:44 pm

Thanks Martin. Good to know that my Mk 1 eyeball is so well calibrated!

Hank Roberts May 27, 2010 at 1:57 pm

> is he claiming that this represents global temperatures ….?
"The data in my paper comes from oxygen isotope analyses of ice cores in Greenland made by Dr. Minze Stuiver and Dr. Peter Grootes, long recognized as the world standard for accurate paleotemperatures over thousands of years and used by thousands of scientists all over the world."http://climaterealists.com/attachments/database/R

But there's no data in his paper, just a picture, which isn't what he says. So it's hard to tell.

> Monckton
"If you buy an outfit you can be a cowboy too" applies — the Guardian a while back quotes the House of Lords as saying there's no penalty for falsely claiming to be a member, in an article on his various candidacies. http://www.guardian.co.uk/environment/blog/2010/a

gavin May 27, 2010 at 5:39 pm

It's worth pointing out that the 'new graph' is an old one that Easterbrook has been using for years – and if you are careful, you'll notice that it has been mislabelled for years as well. His MWP is at least 1000 years out – (it should be the first bump if anything) and his LIA is wrong too.

Tony May 27, 2010 at 11:21 pm

Just out of interest, did anyone see Noel Cheer's interview with Vincent Gray on Stratos last night? It is so reassuring to hear from the master that there is no problem associated with rising greenhouse gases, its all just environmentalist driven propaganda. It's amazing how far you can go with half truths.

Gareth May 27, 2010 at 11:45 pm

Is it available on Youtube? I'd quite like to catch up on what the old master's saying these days…

Hank Roberts May 27, 2010 at 11:58 pm
Gareth May 28, 2010 at 12:02 pm

Dan "repurposed" my original post: Monckton & the case of the missing Curry

bill May 28, 2010 at 6:40 am

Nice to see you finally got the 'h/t' credit at the bottom there! I was getting worried! No sign of Old Scrotum, though…

Hank Roberts May 28, 2010 at 4:25 am

Ah, what goes around comes around — so did you compare that stretched and flipped curve to the others?
Link above is munged, it's at:http://hot-topic.co.nz/monckton-the-case-of-the-m

I'm curious how well that "original"-after-stretching-and-flipping matches the one from globalwarmingart

Gareth May 28, 2010 at 4:36 pm

I took the curve directly from Cuffey & Clow 1997 but didn't try my own plot of the data. Once I was sure Monckton had the reference wrong, my case was proven. This latest investigation led me to the Alley temp data, which is what I suspect Monckton actually graphed. He may have got the idea from an earlier Easterbrook presentation… In septic circles, what goes around certainly comes back.. ;-)

ctg May 28, 2010 at 8:39 am

Isn't that the sort of social networking behaviour that Wegman said was unhealthy?

Hank Roberts May 28, 2010 at 3:02 pm

> compare
I didn't mean plot Cuffey/Clow's data, though I'd be curious to know if it's actually available, did you find it in the paper or a reference to where they got their data points? I was just wondering how a blink/overlay of the stretched-and-flipped plot compares to the Monckton/Easterbrook thing; I'm still wondering whether some actual single data set lines up with the combined result of the eight proxies in the globalwarmingart chart. My recollection was that globalwarmingart says the GISP2 proxy line (light blue?) shown there has a lot more variation than the merged (black)–but I don't know if it's even the same GISP2 data.

Eventually it gets too tiresome to chase this stuff, especially since Easterbrook is sure he has on his own computer the actual data he charted, if he'd only cite it or post a copy of it somewhere.

Perhaps he's signed a nondisclosure …. no, don't go there.

Carol C May 28, 2010 at 7:07 am

Speaking of Monckton, I have just finished watching the presentation by Prof John Abraham linked at the top of this page. Well done, Prof! And thanks for having the link here, Gareth. Abraham goes through many of the Monckton claims and shows how the man has twisted the facts to suit his own agenda.

I loved what the prof said at the start – American audiences feel the English accent has authority (that's a misquote but is the gist of what is said).

TrueSceptic May 28, 2010 at 5:02 pm

Which is funny in itself because British actors often play the "bad guys" in Hollywood films because of the accent.

Glacier Guy May 28, 2010 at 3:08 pm

Gareth, based on your observation that plotting the actual GISP data (from either Alley 2004, or Alley, 2000) shows significantly more detail than Easterbrook's graph does, I'd wager that he actually just copied the graph posted on the web of Alley's (2000) temp and accumulation data (seehttp://www.ncdc.noaa.gov/paleo/pubs/alley2000/all… I think it would be consistent with his penchant for using other people's graphs (not the raw data), often with no attribution, or the wrong attribution.

Gareth May 29, 2010 at 2:48 am

Looks familiar!

Glacier Guy May 30, 2010 at 1:33 am

Thanks Gareth…that's it! I didn't know how to post it.

Gareth May 29, 2010 at 2:57 pm

And… there are some scaling differences between my plot of Alley's numbers, and both Easterbrook's curve and the Alley.gif above. The 10k point is the same on all three curves, but Easterbrook/Alley's 5k point is different to mine. This could be because I didn't treat the x-axis as a timeseries, but just treated each point as being equally spaced in time. I need to go back to the data and check… But the difference is evidence that Easterbrook is following Alley.

(And having checked, I have the scaling wrong, not Alley. The most recent data points are 7-10 years apart, but that increases to 20+ years as you go back in time — which is not surprising, because the snow accumulation varies as well, as the chart above demonstrates. I'll edit the chart to reflect that)

Neven May 29, 2010 at 7:43 pm

On a Dutch webiste for skeptics I have come across this graph by Easterbrook. It looks fishy – apart from the fact that it stops in 2008, during the last La Niña – but I lack the knowledge to judge if this graph is misleading as well. What do you guys think?

ctg May 29, 2010 at 8:55 pm

Gareth mentioned that graph in an earlier post. The comments on that got sidetracked by a troll, so the graph itself didn't get much attention.

At the time, I was going to comment that the "IPCC projected warming" line on the graph looks distinctly odd. It's a jaggedy-up-and-down line, which doesn't look like normal IPCC projections – they typically show multi-model means with error ranges, like here for example. The graphs usually show several different emissions scenarios.

Easterbrook's line looks like it could be the output of one model run under one scenario, but that would be a very odd thing to show. It certainly doesn't look like any of the projections in AR4 WG1 chapter 10.

Glacier Guy May 30, 2010 at 1:31 am

CTG, your take on the graph is the best (really, the BEST) I can do, and I've looked in to this one a lot. Easterbrook ends most of his talks with some version of this "IPCC" (or normally mislabeled "ICPP" or "IPPC") forecast with a very specific spagetti line. It's actually a prediction, not a forecast, and the IPCC does not do Predictions! that would be ludicrous to any conscious climate scientist, let alone to a whole possy of them!

I have been at talks where Easterbrook was asked about this graph specifically, and he insists that it "was on the IPCC web page!" and therefore somehow is legitimate. No matter that it makes no sense in terms of all the methods the IPCC (or any climate modeler) uses, let alone that it has never been the primary forecast of any IPCC publication, he uses it as a strawman that no lay person without understanding of climate science would understand. That no media or broader publications nail him on this frustrates me no end!

Neven May 30, 2010 at 6:42 pm

Thanks for the answer, ctg. I knew I had seen that graph before.

A Bryant May 31, 2010 at 8:35 pm

Gareth, you (and Martin M and others) have done some very good detective work here…much appreciated! Your plot of Alley's (2000) data is accurate (or at least I get the same result when I did it). However you have plotted Easterbrook's "present =1905" too far to the left…it should be very close to the right-hand Y axis (the year 1905 equates to 0.095 thousand years before 2000).

I also downloaded the GISS anomalies for the Angmagssalik station. The trend over the 1905-2004 period is not significantly upwards or downwards. However the average value over that century is -30.6 degrees C, with 95% confidence intervals of -30.8 to -30.4 degrees. This is a little less that a 1 degree above Alley's ice-core record temperature reconstruction that ends in 1905.

The key message is that Easterbrook demonstrably plagiarized material, modified it and mis-represented it as something that it wasn't. I was always taught that in science this kind of behaviour is generally frowned upon.

Bravo, and keep up the great work.

Gareth May 31, 2010 at 10:18 pm

Hi Andrew,

Thanks for the kind comment. If you take a look at the bigger version of my graph (click on the one in the post), you can see more clearly where the Alley data stops and my straight line begins. It should be at 100 yBP, give or take a gnat's whisker. Re the temperature at the GISP2 core site, see the paper referred to in MartinM's comment above. It suggests that 2.5ºC is about right for the warming there. In any event, and as you say, the precise detail doesn't change the central message – that Easterbrook is begin deliberately misleading when he calls 1905 "modern".

A Bryant June 1, 2010 at 11:18 am

Thanks Gareth,
The plot of Alley's data is accurate (I also used original data…thank you MartinM).

My nit-pick is that the red label (and arrow) showing Easterbrook's "present day" is plotted too far to the left. Alley's reconstruction endpoint (year=1905) should be located at 0.095 on the X axis (i.e., exactly where your estimated 2.5ºC/Century incline begins). As it stands the red arrow points towards 3k years BP. That is incorrect.

Again, thanks for a terrific website. It is one I enjoy following. Send me a pm and I would be happy to help. And yes, I do have the necessary skills to do so.

Gareth May 31, 2010 at 11:35 pm

Ah, I see what you mean. I drew the arrow to point to the line, not to replicate its precise position on Easterbrook's original. I'll follow up by email. Cheers.

Phil. June 4, 2010 at 10:16 pm

I was wondering why you were referring to 1905, my understanding is that it is 95 years before present, but Alley's data uses the conventional 1950 = present so it should be 1855.

Gareth June 4, 2010 at 10:38 pm

That's an interesting point. It's not clear from the header to the data file whether Alley uses 1950 or 2000. I assumed 2000 because that was when his original paper (Alley, R.B. 2000. The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews 19:213-226.) was published. If it really is 1950=P, then Easterbrook's being even more deceptive!

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