I’ve re-read section 7 of IPCC 1 [1990], which contains the graph used in the WSJ editorial. I highly recommend that everyone interested in this topic take a look at IPCC 1. First of all, here is a scan of Figure 7.1 together with the original caption.
Original Caption: Figure 7.1. Schematic diagrams of global temperature variations since the Pleistocene on three time-scales: (a) the last million years; (b) the last ten thousand years, and (c) the last thousand years. The dotted line nominally represents conditions near the beginning of the twentieth century.
Compare this caption to John Hunter’s recent comment:
” the pre-Mann temperature graphic from the IPCC 1990 report” is, presumably, Figure 7.1 of Section 7.2.1, the caption of which reads: “SCHEMATIC diagrams of local temperature ….". (My [JH] emphases.)
Notice the difference between Hunter’s description and the actual caption: Hunter quotes the caption as "local", while the actual caption is "global". I think that I’ve seen the same mischaracterization elsewhere.
Climate Audit 
82 Comments
Do any of these people put numbers on their graphs? Just how much did the the temperature change? Is each tick mark 0.1 C, 0.5 C, 1.0 C? This happens regularly with climate data. A few weeks ago you posted a set of tree ring measurements by some of Mann’s supporters and there was no scale or label for the vertical axes. What gives?
Well, McIntyre?, that’s a rather grubby little post isn’t it? Normally, and this is a compliment, you do try to keep above the fray and keep your hands relatively clean.
So, I guess we can assume you haven’t asked John Hunter for his explaination (a typo I guess)? No, you just make a personal attack on him. Rather demeaning imo (and before someone comments, yes, yes, I know what a wicked evil person I am…).
Peter, I didn’t make a personal attack on Hunter; I simply pointed out a difference between his characterization of IPCC1 and what it actually said. I try to stay away from adjectives and editorializing (as I’m pleased that you noticed), but I do try to make points by comparing what people say with actual records. I think that my post is exactly within that spirit. I don’t view Hunter as exactly being a civilian in this. He works pretty hard to find the slightest imperfection whatever in my material, while ignoring blatant defects at realclimate. If there is anything demeaning, it is not what I said, but Hunter’s prior post. However, the real reason that I highlighted his comment is that I’m pretty sure that I’ve seen the same point made elsewhere and these things can quickly become urban legends. I thought it worthwhile to try to do what I could to stop this one.
I’m curious why a "schematic" with a y-axis corresponding to delta T would find it necessary to specify Celsius. If it’s simply a schematic, it shouldn’t matter if it’s degrees F, C, or K, right?
Steve: The running text refers to Figure 7.1 stating that it shows a range of less than 2 deg C. Thus each mark is 0.5 deg C.
So, you think we could get an urban legend that people would think the 1990 graph said ‘local’, not ‘global’? I think not.
I do think people might start not to trust those reseaching past climate – of course what you’re doing wont aid that…:(
But, what is important is that John Hunter was right, bar the odd typo, about what he said. The 1995 IPCC report does rather prempt the detested MBH stuff. Odd that eh? Doesn’t fit with the myth of the sudden appearnce of hockey stick type thinking, but it happens to be the truth! And I HAVE read the page quoted, I’ve got copies somewhere 🙂
I’m also curious to know whether someone like Steve would’ve been afforded the luxury of “a typo I guess” should he have made such a blunder of typing “local” instead of “global.”
I have a question and possibly a research suggestion.
In the Mann et al. work, is the calibration done with global temperatures or local temperatures, i.e., is one global temperature series used in the analysis for all proxy series, or is each proxy calibrated to a different local temperature series?
If it is the former, that would seem odd. How is a North American tree supposed to know the global mean temperature? What is the recent local temperature trend for the most influential series the bristlecones I presume)? Has there been recent local warming? (I seem to remember that there has been little temperature increase in North America.) If there has been no recent local warming, why are they trending upwards.
Shouldn’t each proxy series be used to estimate historical local temperatures and then the results aggregated up? (That is my research suggestion.)
If it is the latter, then we get very different reconstructions for different regions, don’t we? How do the reconstructions differ? Do we see a MWP in some areas and not others?
If you have posted about this elsewhere, you can just point me there. If this is too ignorant a post, feel free to ignore it.
Steve: He calculates principal components from the temperature data matrix and regresses against them. These PC series are weighted averages of temperatures in various parts of the world. ThePC1 is a lot like a global average. I agree that it makes no sense to think of individual bristlecones somehow “channelling” a global mean temperature. Local temperatures do not explain the bristlecone growth spurt. Graybill and Idso attribute the increase to CO2 fertilization and there is much evidence of this.
Other multiproxy studies more or less do aggregates without the complicated MBH98 procedures. Then it all depends on whether the individual “proxies” are any good. For example, Crowley and Lowery use 2 bristlecone series, which are very important in giving it whatever hockey-stickness it has. It also depends on cherrypicking. For example, Thompson’s Dunde ice core dO18 series has a strong 20th century trend, others don’t. If you cherrypick series with a 20th century trend, you will get a hockey stick shaped aggregate.
Peter, I think you are the one who is being a little unfair to Steve here. Go back and read John Hunter’s comment again. It is not just his typo on the caption that makes the claim about the previous IPCC representations of temperature history being “local” rather than “global”. It is a running theme in the whole comment.
Steve and Peter: Well I hope Steve grants me the right to reply. Yes, of course it was a typo — I guess if you thought it was an attempt to mislead then you could probably detect Reds under the bed. I did after all exhort people in a later post to actually go and READ the 1990 IPCC report, but Steve must have regarded that as an offensive suggestion and censored that part (perhaps he didn’t WANT people to go and read it …..). Anyway, thanks for your support, Peter — a rare breath of fresh air on this site. Now, I wonder how much Steve will snip from this posting …..
Steve: Hunter’s original comment was, in effect, a lengthy commentary on what he argued to be inappropriate or worse use on my part of the word “seamlessly” in a short blog comment. So Hunter obviously believes that individual words matter.
I re-examined IPCC 1990 for a variety of reasons and observed that the actual caption to Figure 7.1 differed from Hunter’s characterization. With the caption as represented by Hunter, using Figure 7.1 as used in the editorial would be wildly inappropriate; with the caption as it actually exists, Figure 7.1 can be legitimately introduced into the debate. Hunter’s error was highly material to the interpretation and was extremely misleading to a reader. I reported Hunter’s error. I did not impute motives. I did not speculate as to whether it was a typo or an deliberate attempt to mislead. I did not suggest that Hunter was malicious or incompetent, I merely reported the error so that readers would have an accurate record.
I disagree with Hunter’s statement that his error is excused by the fact that he also urged people to go read the report. Not all readers of this site have access to university libraries with the 1990 IPCC report. Also Hunter cannot assume that people who do will actually attempt to cross-check his quotation for accuracy. I wasn’t crosschecking Hunter specifically, but I was aware of his comment when I was reading IPCC 1990.
In the past, if there’s a choice between imputing a sinister motive or an innocent motive to an error, if I’ve ventured an opinion, it’s nearly always to give the benefit of the innocent motive. For example, in Mann’s principal component algorithm which was misrepresented in MBH98 – the innocent explanation is that it was a computer error; the more sinister explanation is that Mann intentionally applied a procedure that was designed to mine for hockey sticks and misrepresented the procedure in MBH98. In our EE article, we speculated that it was probably a computer error. Now Mann himself seems to be arguing that the procedure was intentional and misrepresented.
Not only do I not have any objection to the idea of people actually reading the 1990 report, when I re-read the pertinent sections of the 1990 Report, I think that there are many extremely interesting points made in it and have typed up big chunks for posting here.
Hunter frequently inserts gratuitous and unsupported accusations like the above: that I found something “offensive” and “didn’t WANT people to go and read it”. I get a little tired of unsupported personal comments like that from Hunter and would ordinarily snip them from his posts; because of his track record, I’m probably a little quicker with the snip with him than with others.
Slippery behaviour. Unfortunately I dont know who John Hunter is or where I might read his output ( Could someone post a link ?).
Off topic: Following the hostile commentary at RealClimate.org Veizer’s paper has been made available by Geoscience Canada at http://www.gac.ca/JOURNALS/geocan.html
(Scroll down the page a bit to find it).
Peter, my point is that to make such a typo, John must have been in the habit of thinking of the previous evidence as pertaining only to local climates. The whole tenor of John’s remarks, and a developing mythology, is that the pre-Mann “official view” of the last millennium was that the MWP was only a local phenomenon. Yet as the actual caption shows, at the time people did not think the MWP was a local phenomenon — they thought it was global.
Re #8. Peter, one post in the thread you refer to stands out, it’s not by JH, it’s post #12. In that post Michael Mann is accused of ‘lying’, the IPCC of bias, religious thinking, hiding data and Jones and Bradley of ‘bad science’. All, apparently, perfectly acceptable behaviour! So, we have to assume JH makes worse comments than that. Humm, I doubt it – infact I’d go so far as to say I’d find that astonishing if it were true.
JH quotes various IPCC documents. He’s seeking to make a point (about the evolution of the HS) so his quotes do that. Don’t you use data that backs you up when you make a point? He accuses no one of lying, no one of religious nuttery, no one of hiding data. Draw your own conclusions.
I think the most interesting part of the 1990 IPCC report is the appendix with different projections for the future increase in atmospheric CO2. Sufficient time has elapsed to compare these projections with what actually has happened in the atmosphere. I was not surprised when I found that the real world increase lies below all this 15 year old projections.
re 10:
John Hunter’s Home Page at the Antarctic Climate & Ecosystems Cooperative Research Centre
What’s wrong with What’s wrong with still waiting for Greenhouse?
Re#10,
I did a google search and came across this discussion involving Mr. Hunter http://www.debunkers.org/ubb/Forum2/HTML/000682.html .
Steve:: Michael, let’s lower the temperature. Steve (update): [of the exchange] i.e. be a little more polite.
Re#4,
Thanks for the clarification, Steve. Of course, if they have x and y-axes to scale and assign units and tick values to them, I don’t quite understand why it’s described as a “schematic” (which Mr. Hunter felt the need to emphasize with caps).
Then again, maybe it’s all semantics. I questioned why MBH98 was considered a “reconstruction” the other day on realclimate.org. Gavin responded with a definition for “reconstruction” which certainly fit MBH98, but it referred to a reconstruction as an “interpretation.” I then questioned why/how an interpretation could be considered “science,” but my post has yet to appear after an elapsed time of 24 hrs.
Steve (posting #9): Thanks for at least posting my last comments without censorship.
Many would view your overall endeavours as “nitpicking”. There is also a nice piece by James Annan arguing that you are basically “making mountains out of molehills” (http://mustelid.blogspot.com/2005/02/trying-to-create-mountains.html). And (if we needed any more evidence) we now have a new thread (to date amounting to 14 postings), based on a SINGLE TYPO in completely different thread!
Peter (posting #12): I actually submitted a posting pointing out the ad-hominens in the posting #12, to which you refer (it’s in thread “WSJ Editorial”): Steve censored that one completely!
Isn’t there a contradiction between the long term graph in this post and the one in
http://www.climateaudit.org/index.php?p=214 Titled “Climate: Geological Views#1”
This post’s graph would imply in the long term view we are closer to the all time highs than the lows. The graph in the other post “Climate: Geological Views#1” shows the opposite.
Curious as anyone’s comments on that
Hans,
Re:14
I forgot about Hunter’s site and noticed some comments about Tuvalu.
I have a nephew in the RAN who personally knew the scientist who did the scientific work on sea levels at Tuvalu over a period of 3 years. (She was the wife of an RAN officer stationed there for the period).
I cannot name names, but she concluded there was no change in sea level apart from natural variation. She handed her report to the Tuvula government who then, it is alleged, were displeased with this result, changed it in order to retain World Bank Funding, thus creating the present argument that Tuvalu is facing imminent burial at sea from rising sea levels.
Of course we must also include the buried parts of the Ptolemy era Alexandria which is also underneath 20 metres of sea at the mouth of the River Nile. Another case of unreported glowball vorming! from the ancient past.
This fact of political chicanery with a scientific report changed my nephew’s view on the whole issue.
But what startles me is the level of personal invective aimed at anyone who dares question climate change. There is a general belief that climate sceptics are paid by Big Oil, Big Mining and Big Coal. There is an odious remark that we in the Lavoisier Group are so funded. News to me – I sent $250 of my own personal funds to help with some funding for the Lavoisier Group recently. If we had the backing of Big COM this would not be necessary. Mind you the climate changers have the backing of the taxpayers, which we sceptics could not match in our wildest dreams.
Some of the comments here are examples of this tendency, and this is sad.
Louis Hissink (posting #20):
If you really want to find out for yourself what is happening at Tuvalu, here is what you can do:
1. Obtain the historic sea level data for Tuvalu from the standard repositories of such data, which are the Permanent Service for Mean Sea Level (http://www.pol.ac.uk/psmsl/), the University of Hawaii Sea Level Centre (http://uhslc.soest.hawaii.edu/) and the Australian National Tidal Centre (http://www.bom.gov.au/oceanography/projects/ntc/ntc.shtml).
2. Obtain survey data giving relative rates of vertical motion of the gauges (from the same sources as (1), above).
3. Combine (1) and (2) and apply standard linear regression techniques (with due regard to uncertainties) to estimate the trend in relative sea level at Tuvalu.
Then tell us the result.
Re 19.
Buck, easily answered.
The geological graph you linked to shows average global temperature over time.
The graphs at the beginning of this thread while unlabelled, can be reasonably assumed to be temperature anomaly graphs simply because they have a canny ressemblance to other graphs so labelled elsewhere.
The two data sets cannot be compared actually – since temperature anomalies are departures from an arbitrarily defined moving average, usually 30 years if I have it correct.
The graphs on this post show variation AROUND the mean temperature over time, defined by a moving average, while the geological example linked shows the variation OF the absolute mean temperature over geological time.
Apples and oranges hence the contradictions you have noticed.
This is why climate change is really alot of statistical skullduggery – which Steve latched onto a few years back.
Think of it this way – the linked graph shows the variation of the the global mean temp over time. The ones here the variation of the variation around the mean temperature over time. If they plotted the mean temperatiure itself I suspecy global warming would instantly cool down.
A perfect example of template statistics when you know statistics by rote or from canned maths programs. And why there are no geologists on the IPCC.
We have superb bulldust radars – well those of us in the mining industry have, at least.
OK got it – these three graphs are derivatives of the first one, right? So by any rational measure we are still in an ice age and gloabl temperature have been as much as 8-9 C warmer in previous warm periods. What’s wronng with a degree or even two of man made warming?
Louis (posting #22):
> The graphs at the beginning of this thread while unlabelled, can be reasonably assumed to be temperature anomaly graphs simply because they have a canny ressemblance to other graphs so labelled elsewhere.
> The two data sets cannot be compared actually – since temperature anomalies are departures from an arbitrarily defined moving average, usually 30 years if I have it correct.
I think you’ll find that if you take a curve that covers nearly a million years (e.g. the top graph of this thread) and take a 30-year moving average, you get pretty well the original data back. If you then take the difference between the original and this moving average you therefore get pretty well zero — which is not what is shown in the top graph.
It is abundantly clear that the plots shown are NOT “departures from an arbitrarily defined moving average, usually 30 years”. Let’s get a bit of reality into these discussions shall we?
A “superb bulldust radar”? — I don’t think so ….
RESEND w/ edits …
I appreciate your concern on tone (or temperature), Steve — but the debunkers reference of Mr. Jankowski was a terrific read. And except for the obviously less informed on that thread (which are easily discounted for lack of science content and reason), it was Dr Hunter’s posts that served to raise temperature! Were you were attempting to warn us from reading it, for that reason — i.e. prejudicial on its face, to Dr Hunter?
One more point of posters using tactics such as Dr Hunter — as one of many informed readers and participants in this ongoing discussion, I’m always and proudly SKEPTICAL of responses asking anybody to read the IPCC Summary to learn more about the issue. For it is exactly this order/suggestion and the follow-up by those recipients that has many policy-makers, most of the media, and much of the climatologically underinformed masses blindly following that which is insufficiently supported under peer-review in the first place!
JJM
A bit off topic but a very interesting paper on the state of temperature reconstructions:
Click to access GRL_Esper_2005.pdf
“Examination of large-scale millennial-long temperature
reconstructions reveals a wide range of datasets and methods
used for calibration…… We find that these
various approaches alone can result in differences in the
reconstructed temperature amplitude of about 0.5C. This
magnitude is equivalent to the mean annual temperature
change for the Northern Hemisphere reported in the
last IPCC report for the 1000–1998 period.”
Re #20 and #21 http://www.tuvaluislands.com/news/archives/2002/2002-02-01.htm
I see that John Hunter has more than a passing interest in Tuvalu – maybe another audit is called for!
Click to access tuvalu_briefing.pdf
Re#25,
I believe the “temperature” that Steve was referring to was that of additional comments I had made in my post (and which had been censored).
Re #28
Michael, if you or someone can point me in the direction of the Funafuti tide gauge data, I’d like to have a look…
Re #30 John, this looks like the repository for Funafuti sea level data.
http://uhslc.soest.hawaii.edu/uhslc/woce.html
John A and Michael Mayson (postings #30 and #31): Just take a little trouble and read my postings (#21) — I think that gives you all the information you require — but if you do start another witch-hunt and “have a look”, then let’s hear exactly what you do and what results you get ….
Michael Mayson (posting #28): I note that you think that perhaps “another audit is called for”. I wonder why you believe this. Is it because you find my results unbelievable (you certainly haven’t given any justification for such a belief)? Or perhaps it is because you just don’t like the results I found or because you would just like to prove me wrong? — either way, I don’t think such a reaction is very helpful — which is precisely why I suggested it was the start of another “witch-hunt” in posting #32.
To lighten things up a bit …… I guess both sides of these arguments can perceive some of our opponents’ shortcomings in the following site:
http://www.venganza.org/
John (Hunter),
I was looking at the raw data (for Tuvalu), and the most striking thing was the extreme changes from day to day (& month to month) in the sea level. Now, of course, this is mostly from a) tides, b) SST changes (El Nino, etc.), c) storms and other local weather. But given such extreme ‘noise’ in the data and only a bit over a decade of useful data in the first place, how can anything be said about long-term trends? Statistical analysis can’t create something from nothing, or at least it shouldn’t.
Dave (#35): Oh gosh, sorry – silly me, I never even noticed “the extreme changes from day to day” – I just laid my old school ruler through the data points and came up with a rising trend which suited my preconceived notions of sea level rise.
But seriously, Dave, do you think that we don’t consider things like error budgets?
Anyway, read the report which describes the quantitative analysis (with uncertainty estimates) at:
Click to access tuvalu.pdf
You should note the context within which this report was written (read page 4 of the report) – a context in which there were a number of careless (some apparently very accurate) claims being made about sea level rise at Tuvalu – which were, in turn, quoted widely by contrarians such as John Daly.
Also note that you are quite wrong to say that there is “only a bit over a decade of useful data” – there is now 27 years of data – if you take the trouble to look for it in the places I indicated (posting #21).
Incidentally, this is all very old hat – it was discussed at length by the contrarian, Willis Eschenbach, in Energy & Environment last year (Vol 15, No. 3, 527-543), and by me in Volume 15, No. 5 of that journal. (For those keen on maintaining the quality of climate research, it is worthwhile noting that neither of these articles, which were published in what is an actively contrarian journal, were subject to peer review, even though I specifically asked for my own contribution to be peer-reviewed.)
But, like the Mann et al. “hockeystick”, it is old news ….. I’ve moved on.
John,
So your advice to Louis in #21 was just a joke. That’s what I figured, but wanted to be sure. I have read your .pdf before, but I’ll look again. It may be good for a laugh if nothing else.
Yes, I just reread it and got a belly laugh instead of just a chuckle.
If you’d just said, “We looked at all the data from both the old, somewhat shakey data and the stuff from the new gauge and decided the data is just too sparse. Call us in another decade or two and we’ll see what we can do,” that would have been fine. But no, you have to massage the data to death to end up with a shakey figure with the margin of error much larger than the trend, i.e. comfortably containing the null result. But you’ve moved on, so I will too.
Re #37 and #38. Wow, sarky today Dave aren’t we?
Oh gosh, sorry – silly me, I never even noticed I was being sarcastic.
Re #33 A fair point John. However I have read your ‘note’ at http://www.antcrc.utas.edu.au/~johunter/tuvalu.pdf
and find, like Dave did, much straining at a gnat.
You could very well substitute “land subsidence” for each instance of “sea level rise” ( and vice versa) in your note and demonstrate that ( not unexpectedly for a coral atoll) land is gradually subsiding!
However, I have to admit that the real reason for #28 is that I just don’t like your style.
Dave (postings #37 and #38): Sometimes I just don’t understand you people – perhaps Steve can explain. At a time when several people were making quite specific statements that the “sea level at Tuvalu was not rising”, I did the best job I could to see what the data actually said. I estimated the mean trend and it’s uncertainty. I didn’t go any further and say that this proved that sea level was rising at Tuvalu, but merely indicated that, to say something like “the evidence shows that sea level is definitely not rising” was untrue. I should add that my report was reviewed by three of the most experienced scientists in this field in the world.
Dave’s response is sarcastic and wrong — I did not “massage the data to death” — I used quite standard analytical techniques. Dave’s uniformative and ill-informed statements don’t do the case of the contrarians any good at all.
Perhaps I should add that the results for Tuvalu are actually quite consistent with estimates of global sea level rise for the 20th century. We are now confident that this was between 1 and 2 mm/year, and a figure around 1.8 mm/year is highly probable.
As I said, I’ve moved on. More recent analyses of the (now longer) Tuvalu data and the availability of more comprehensive survey information indicate that sea level rise at Tuvalu is probably around 2 mm/year and statistically positive at the 90% confidence level.
In what I hope is a serious note, have there been attempts to measure any possible land movements at Tuvalu ? I can see that it might not be easy to measure to +/- 1 mm per year, although possibly some form of measurement by Satellite might be able to claim such accuracy ?
John Hunter’s paper refers to a presumed stable point on the island as a point of reference which is not unreasonable at all for relative movement. In fact the apparent fact that there is no relative movement between that point and the more recently installed tide gauge would suggest that any tectonic actual land subsidence or uplift was affecting the whole island equally. Tectonic may be the incorrect term, but I use it to differentiate it from localised movement such as affects the older tide gauge.
Second query, if the El Nino tidal variations are so marked, is there a similar but opposite effect noted for La Nina occurences ? If so, or even if not so marked but they exist, should such variations also be excluded if El Nino variations are classified as outliers to avoid removing only prominent outliers to one side ? Presumably over the longer term however, these fluctuations would even out.
Michael (posting #41):
You “find, like Dave did, much straining at a gnat” — I’m not sure what gnat I’m straining at — an example would be good — I’ve just been looking at data and describing it as best I can. If you can find anything I said in the report that you believe to be unfounded, I’d be glad to hear of it — no one with any reasonable competence has managed to so far.
> You could very well substitute “land subsidence” for each instance
> of “sea level rise” ( and vice versa) in your note and demonstrate
> that ( not unexpectedly for a coral atoll) land is gradually subsiding!
I guess you aren’t really conversant with the technical terminology. The Executive Summary starts with the sentence:
“This document describes an analysis of long-term relative sea level change at Funafuti, Tuvalu.”
Now “relative sea level” means just that — i.e. sea level relative to the land. There is no pretence that my estimate was a measure of anything other than this. But remember that the type of sea level that floods the land is RELATIVE sea level (be it due to an “absolute” rise of sea level or a subsidence of the land).
>> I just don’t like your style.
I’m sorry — again, I am not sure what you mean — but presumably you regard it as a good reason to suppose that “another audit is called for” (i.e. “I don’t like what he says or the way he says it, so lets have a witch-hunt”).
Ed (posting #42): As regards Tuvalu, a GPS recorder has been in place for several years to monitor vertical land movement. However, we need several more years of data before we can detect the vertical movement with sufficient accuracy for use in sea level studies.
We can also estimate the vertical movement of the land caused by glacial isostatic adjustment (or postglacial rebound) using numerical models.
As regards La Ninas — these are associated with the “high” sea levels in between the “low” levels which are associated with El Ninos. As you see in my report, I derived a “less cautious” estimate of the sea level trend by regarding the El Nino lows as outliers — these are by far the most “spiky” elements of the record — but you are very free to ignore that estimate and accept only my “cautious” one, which included all the data. And yes — these peaks do even out in the long term, but (as in many climate investigations), we are forced to make inferences from data which is really shorter than we would like.
Re #44 Why not “relative land level”?
re#42 When you subtract large numbers from large numbers in an attempt allow for known differences, all sort of errors are possible. When the results then contain 0 as a reasonably possible value, then I don’t think it behooves you to get upset with people who think there’s other evidence that shows no sea level rise.
I’ve seen you in action before, John, both here and elsewhere, and you tend to be both sarcastic and pompous. Well, carry on, but don’t expect me to cut you any slack.
Michael (posting #46):
> Why not “relative land level”?
Is this a serious question, a joke or just an effort to avoid the emerging and obvious conclusion that no one can find any serious criticism of my report on relative sea level at Tuvalu (which is pretty obvious, given how simple, straightforward and open that analysis was)?
Dave (posting #47):
> When you subtract large numbers from large numbers in an attempt allow
> for known differences, all sort of errors are possible.
As I said before, I did my best estimate of the error budget for relative sea level rise. If you can suggest something I omitted or got wrong then please tell me — I assume you can’t since you are reduced to the weak statament that “all sort of errors are possible”. Or better still, do your own analysis (as I thought John A and Louis were going to do), get it peer-reviewed and actually contribute to the science.
> When the results then contain 0 as a reasonably possible value, then I
> don’t think it behooves you to get upset with people who think there’s
> other evidence that shows no sea level rise.
I’ve lost count of the number of times I’ve explained this, but I’ll go over it one more time. Prior to my writing the “Tuvalu report”, a number of people claimed that the sea level records at Tuvalu showed that sea level was not rising at Tuvalu. Most people would take that to mean that there was evidence in the sea level records that sea level rise was significantly less than the oft-quoted IPCC (2001) estimate of global-average sea level rise of 1-2 mm/year. So I looked at the records and showed that THE UNCERTAINTIES WERE TOO LARGE TO MAKE SUCH STATEMENT. I also noted that the records were consistent with the estimates of global sea level rise (and also, of course — but at a rather lower significance — with zero sea level rise). If you want to argue that I UNDERESTIMATED the uncertainties, then you are just providing further support for the case I was making — i.e. that people who said that the sea level records at Tuvalu showed that sea level was not rising at Tuvalu were WRONG. That does not of course mean that the converse is true — that the sea level records at Tuvalu showed that sea level WAS rising at Tuvalu — but I’m sure you (like many contrarians) will fail to understand that subtlety.
> you tend to be both sarcastic and pompous
After posting #37 and #38, I thought I’d well and truly lost that competition.
Finally, if you want to know something about GLOBAL-AVERAGE sea level rise, don’t look at Tuvalu — the record is too short and it is only one record. However, there are ample records around the world to support the 2001 IPPC estimate of 1-2 mm/year, and more recent eveidence to suggest it is around 1.8 mm/year.
Re #49 “…the case I was making — i.e. that people who said that the sea level records at Tuvalu showed that sea level was not rising at Tuvalu were WRONG.”
I thought you had only made the case that there was a change in the relative levels of sea and land and it was thus not possible to say which had moved. I guess you aren’t really conversant with the technical terminology.
Michael Mayson (posting #50): Don’t play silly games. All the people whom I criticised for saying that “the sea level records at Tuvalu showed that sea level was not rising at Tuvalu” were talking about RELATIVE sea level at Tuvalu (i.e. that which is measured with a tide gauge). If they WERE talking about “absolute” sea level, which introduces ANOTHER poorly-known variable and increases the uncertainty still more, then they would be even more wrong.
Again, sometimes you people do yourselves no favours. You certainly provide excellent publicy-available examples of the tactics used by climate contrarians!
Re #51 OK John. But you are fun to play with!
Michael (posting #52): I don’t think it’s funny. I take my job and global warming seriously. At least Steve has some technical capabilities, has an awful lot of energy and he probably believes he is doing the right thing. A week or so ago, I though Louis and John A were going do do an “audit” on Tuvalu — after all, constructive criticism is useful. The response I have seen so far has been nothing short of pathetic.
John, I don’t see that your Tuvalu paper particularly needs an audit, the conclusions are not strong and you sensibly defer trenchant observations on the consequences of any particular outcome. I think you make your point, that those who claim that the sea level at Tuvalu is NOT rising are taking too strong a stand on the data, but equally the data does not really support climate alarmists either. I suggest that the 0.8 +/- 1.9 rate is on more solid ground, eliminating the El Nino variation strikes me as probably inappropriate given that it is part of a 2 way swing, albeit the most prominent part. As such it is not what I would call a “traditional” set of outlier points. However I believe that you have explained and addressed this quite adequately in the paper and would not quibble with the inclusion of the alternative analysis as long as it is not misused in the same way skeptics have misused data with a 1998 end point.
I have tried researching calculations of any isostatic land movement in places such as Tuvalu, but it does seem that the field is in a certain degree of flux (see for example Kendall, Mitrovica & Milne 2005) and that world wide calculations which attempt to determine a change in shape of the earth amongst other things, are not able to provide much useful data (to the required accuracy) at present. Maybe the new Ice-5G program once validated by satellite data will improve matters. In the meantime, waiting for a satellite derived value is probably quicker for Tuvalu.
As a matter of interest, I wonder what parts of the world are sinking by this measure, surely such places must be suffering considerable change, if they are sinking at a rate of 1 mm/year (and there appear to be places rising at that, and you imply that Tuvalu could be rising by at least that), then a 25 cm (1 foot) change since 1880 must be very obvious.
Strange is it not that discussions involving real data are far less confrontational. If Michael Mann had presented his findings and data with as much openness, perhaps this site would never have started in the first place.
re#54 Perhaps I’ll have to go back and read John’s paper one more time as I didn’t see him as having “explained and addressed this quite adequately” either on El Nino or some other variations.
In any case, I went back to John Daly’s site and read what I could find there, and at least in the one post I found, what he said was not that there was no sea level rise, but that there has been no acceleration in the historic sea level rise. Perhaps John Hunter is referring to other nay-sayers on Tuvalu, or perhaps there’s other material at John Daly’s old site which I didn’t find which say what Hunter’s paper claims, but if the actual point is an increase in an historical rise rate in sea levels, then I don’t think the paper shows what Hunter was trying to show.
John Hunter, (or anybody else that may know the answer), what are the units of measurement used in the Funafuti sea level data files?
I believe the measurements are millimeters compared with some benchmark.
Dave (#55): My report on Tuvalu describes exactly which claims I was refuting, so I won’t repeat them here. As for the old chestnut that “there has been no acceleration in the historic sea level rise” — there appears to have been little acceleration in global average sea level during the 20th century — this was made clear in the IPCC TAR. However the long European records that stretch back considerably further in time to show an acceleration from virtually no sea level rise prior to the 20th century to a rise of 1-2 mm/year starting around the end of the 19th century (see the IPCC TAR for this). Also, archaelogical and other evidence indicates that sea level 2000 years ago was close to today’s (after allowance for vertical land motion) — which would not allow the present 1-2 mm/year to be acting throughout that time. In fact it could only have been acting for about the past century.
Greg F (#56): I’m not sure which records you are talking about. The raw archived data which is publicly available is normally in mm (but information on the archive site would give you a definitive answer on this). All my processed data and results are in metres.
David, I’m only offering an opinion, and I though that from my point of view that I understood the processes being used and that were sufficient caveats for me to disagree (or not) without invalidating John’s arguements.
I was reading a bit further on the accuracies associated with GPS determinations, and I noted that the inaccuracies quoted at one point were around +/- 3 mm EW, +/- 5 mm NS, and +/- 10 mm vertically (quoted as 0.01 metre). That sounds a lot, and it would make the detection of movements in the order of +/- 2 mm annually rather harder to detect, although over a sufficiently longer period I suppose some signal could be extracted. That is if there are no systematic +/- errors or changes that are not well known, which might be hard to prove.
I return too, to the interesting query as to where are the areas where the land surface is systematically sinking, and I can only from memory, recall the South of England, the SE if I recall correctly. I estimated a place with a 2 mm annual land sinkage, plus a 2 mm predicted sea level rise , over 125 years from 1880, is a 4 mm annual change, times 125, is 500 mm, or 1/2 a metre. Very obvious I would have thought, and there are places where the land is rising at +12 mm/year (Sweden), where the level changes ARE obvious. ? But where is this sinking happening ? Can I be wrong in assuming that post glacial (and other) changes to the earth’s shape result in a more or less even rising/sinking mix, and that instead the great majority of the land is rising ? I am ignoring localised subsidence, like Venice for example, where purely local effects can account for the sea-level changes.
Any comments ?
Re:#59
The raw archive data is what I am interested in. Thanks John.
re#60 Well, if you’ve studied plate tectonics much, you may remember that there’s a cycle which islands in the ocean go through which includes subsidence as the distance from spreading centers increases. This means that after having been built up by volcanism (usually from hot-spots as in Hawaii) and then eroded, a now relatively flat island starts sinking and coral reefs build up around the edges of the sinking island, gradually moving toward the center.
Of course, superimposed on these tectonic / biologic processes are sea level rises and falls from ice ages and other processes. I don’t know the exact status of Tuvalu tectonically, but it’d hardly be surprising if the island is slowly sinking, quite apart from any sea level rise from melting ice or warming water.
Dave, thanks, I guess the spreading centre uplift and subsequent “downdrift” is another cause to be factored in. I was thinking in particular of the calculated changes to surface height via the Ice-3/4/5 series of programs. There are two sort of effects I understand that these calculations are dealing with, a “local” effect of post glacial rebound and some related subsidence in areas where the surface was icebound, and a global effect where the localised changes relating to the glaciation and the rebound have a wider effect on the shape of the earth. Local effects can be quite marked, as noted above parts of Sweden are apparently rebounding at up to 12 mm per year. Global effects are apparently at least an order of magnitude smaller, but given that sea level changes are in IPCC terms thought to be changing at 1-2 mm per year, such effects cannot entirely be discounted. There are profound uncertainties in the theory at this level of accuracy it seems to me.
I too would not be surprised if Tuvalu was slowly sinking, but it might be a long term project to actually determine this with any degree of accuracy. I mean with all due respect to John’s efforts, I don’t think a change of 0.8 +/- 1.9 illustrates anything in particular.
In terms of long term changes and John’s comment #58, it seems true that there is no sign of any change over the availoable tide records. But for the few that extend back longer, it isn’t that the level hasn’t changed, rather we can’t tell with any accuracy. I still have this problem, lets say that the average sea level rise is 2 mm, which is often quoted. Ignoring land level changes, that is close to 250 mm since 1880, or about a foot, and I don’t think there is evidence of a 25 cm average rise in sea levels world wide. Certainly there will be places like Sweden where uplift means there is an effective drop in sea levels which is noticeable, but on average there must be places where the land is sinking hence amplifying the effect. 25 cm is large and I would expect it to be more obvious, although maybe the assumption that land is averagely stable is wrong and a great majority of the land surface is being uplifted. Call this a sort of common sense test, are we seeing the effects we would expect ?
Dave (#62): I’m not sure what point you are making. If you want to investigate possible flooding of Tuvalu, you look at RELATIVE sea level (i.e. as measured with a tide gauge). If you want to look at sea level rise due to thermal expansion of the oceans and addition of water from melted ice on land, then you wouldn’t look at Tuvalu — for one thing it is only in one place, for another we don’t have good information on the vertical land motion at Tuvalu and for another the record is still too short (27 years) to provide a very useful long-term trend. To estimate the global sea level rise, you look at a number of longer tide gauge records spread over the ocean and/or use satellite altimeter data, and adjust for vertical land motion due to PGR (GIA) using models — as I’ve said before, this indicates a global average rise of 1-2 mm/year over the 20th century — we now know that this is a pretty robust result.
In case it hasn’t sunk in yet: it is wrong to believe that Tuvalu, on its own, tells us anything substantial about global average sea level rise.
John, can you point me to any places where there is clear evidence for a relative sea level rise of around 25 cm since 1880 ?
re#64 Quite right, John. But the whole point of your paper was to disprove something, or more properly, to throw it into doubt; that there had been no sea level change at Tuvalu. Your results were that PROBABLY there had instead been some positive sea level rise, but that no rise was a slim possibility. From what you’ve been saying here you seem to believe that that result is enough to make those you disagree with retract their opinions. I don’t see that as either necessary or particularly useful.
Still, the whole point of the focus on Tuvalu is that the residents there have been claiming that it’s AGW which is causing whatever sea level rise there has been and they should be compensated for it. But if John Daly is correct, that this rise has been happening historically for a long time, blaming AGW for it is wrong unless it can be shown that the rate of rise has increased in line with AGW and your paper really doesn’t address that point since, as you say, “the record is still too short.”
BTW, it’s too bad John Daly has passed away so we can’t discuss his work on the Island of the Dead and what doubt it poses for the global average sea level rise. I enjoyed the back and forth and thought he had the better of it, though I’m sure you’d disagree there.
Ed (#65):
> can you point me to any places where there is clear evidence for
> a relative sea level rise of around 25 cm since 1880 ?
I’m not quite sure what you are getting at, or why you choose 1880. The 2001 IPCC TAR sumarises the evidence from tide gauges (mostly corrected for PGR (GIA)) which shows sea level rise was between 1 and 2 mm/year during the 20th century. More recent papers (Holgate and Woodworth, 2004, and Church et al, 2004) have indicated a rise of 1.8 mm/year since 1950. Satellite altimetry indicates a rise of over 2 mm/year over the past decade and a bit. The long European records (there is a plot in the IPCC TAR) show longer term trends since around 1750. All of the above are of the same order as your 25 cm in 125 years (2 mm/year).
Relative sea level rise at most places will not be hugely different from the above, since PGR (GIA) is mostly significantly less than the “absolute” rise.
Dave (#66): I’m bored with discussing my Tuvalu report. The report initially described its purpose and I think it fulfilled that. If you want to pretend that it had some other purpose and then want to say it didn’t fulfill that purpose, then I’m not going to argue with you.
I’m also bored with discussing the Isle of the Dead. We published a paper in GRL and John Daly sent a comment which was rejected. Prior to the final rejection of John Daly’s comment, GRL asked us to write a response to his comment, which naturally was also not published. Since Daly “published” his critique at http://www.john-daly.com/deadisle/hobart-msl.htm and at http://www.john-daly.com/peerrev1.htm, I also posted our own response at http://www.trump.net.au/~greenhou/reply.html. I don’t see anything else to discuss.
Ed (#54): I did send a quite long and polite response (it started “Thanks for your civilised and considered response”) to your posting #54 but, for some unknown reason, it seems to have been censored. If you send me you email address I’ll forward a copy — I thought it was helpful.
John, I chose 1880 as it is mentioned in a number of places as the approximate year that good records are available from, and it also is a round 125 years. I also note that there is a plethora of comments to the effect that the apparent sea level rise is around 2 mm per year (although this is not a universally accepted figure), that this rise has been in effect from the start of good records, and that there is no (read NO) evidence for this rise accelerating. I agree that 2 mm/year is approximate, some places quote 1-2 mm/year, and some groups believe it is less. In this case I chose 2 mm as a round number, partly to get the 250 mm = approx 1 foot, because it is an easily visualised distance. A 1 foot average rise in sea level is a lot, where it occurs there will be very obvious visual evidence, and I cannot find good evidence for any places where this is occuring outside places such as Venice where any 2 mm rise is literally swamped by loc al subsidence effects. Nowhere in Australia for example is this sort of 1 foot rise apparent (as far as I know), except possibly a few localised areas such as the Port of Adelaide, where local subsidence, again, is occurring. Hence my request for data.
Thanks for the effort in the post, if it was long & polite, then I doubt it was censored, although perhaps John_A could confirm ?
Ed (#70):
You should read Chapter 11 of the IPCC TAR (“The Scientific Basis”).
At http://www.grida.no/climate/ipcc_tar/wg1/424.htm you will read that Douglas (1997) estimated the long-term rate of rise of global mean sea level using “long” tide guage records — he came up with a figure of 1.8 mm/year, so some of the records will have rises less than this and some more.
Also, Table 11.9 summarises estimates of sea-level rise from the long tide gauge records.
Also, Fig. 11.7 summarises the long Europen records and indicates rises of around 10-20 cm on a century timescale.
As regards Australia, Fremantle and Sydney have records of length at least 91 and 82 years, respectively. They show rates of rise of 1.6 and 1.2 mm/year, respectively (after adjustment for PGR/GIA). At Port Arthur, we found a relative rise of about 13 cm between 1841 and 2002.
Ed: The posting numbers seem to have disappeared, but here is a re-post of my response to your posting #54:
Ed Snack (posting #54): Thanks for your civilised and considered response.
> As a matter of interest, I wonder what parts of the world are sinking
> by this measure, surely such places must be suffering considerable change,
> if they are sinking at a rate of 1 mm/year (and there appear to be places
> rising at that, and you imply that Tuvalu could be rising by at least that),
> then a 25 cm (1 foot) change since 1880 must be very obvious.
I’m not really sure what you are asking. Some of the papers describing
models of postglacial rebound (PGR) (or glacial isostatic adjustment, GIA)
give maps of the variation over the globe (e.g. Peltier et al’s papers).
These generally show rates of only around 0.2 mm/year (i.e. significantlty
smaller than “absolute” sea level rise). Tectonic rates can of course be
much larger in some places. I’m not sure where I “imply that Tuvalu could
be rising by at least” 1 mm/year — although of course we believe there
is significant local SINKAGE at one tide gauge site.
> Strange is it not that discussions involving real data are far less
> confrontational. If Michael Mann had presented his findings and data with
> as much openness, perhaps this site would never have started in the first
> place.
I’ve kept away from the McIntyre/Mann controversy over supply of data and
source code as I don’t know all the facts. But here is what I would do
in similar circumstances over the Tuvalu work. If someone came to me asking
for data and source code for the work I did at Tuvalu I’d be hesitant to
provide it, for a number of reasons:
1. The original data is in the public domain and my results should be
approximately reproducible from the information given in my report.
I say “approximately” because even simple analyses like linear regression
can vary slightly (e.g. do we weight the data points by their expected
uncertainty? If so, how do we derive the uncertainty for each data point?).
Also, I’m not interested in quibbling about these small details — if
different people can obtain answers that are comfortably within the quoted
uncertainty of a result, then I’m pretty happy.
2. I’ve moved on and am about to publish newer results for Tuvalu, based on
more recently obtained data. Showing there was something wrong in my
previous work would serve little useful purpose and could involve
significant time on my part in providing data and answering questions.
3. We have to distinguish between raw data, processed data and source code.
The raw data is in the public domain and so is not in question. Source
code, however, is in a very different category, at least in Australia.
The work was funded by the Australian Government and as such they “own”
it. Many governments such as ours have developed a far stronger ownership
of such things in recent years because they realise the value of the
intellectual property that could possibly be sold afterwards, or possibly
used to seed Australian private companies. I am talking very generally
here — I’m sure my analysis software doesn’t fall into that category,
but the fact is that a taxpayer or foreign national certainly does not
have automatic access to software developed with government funding. It’s
a rather similar case to that of our equipment — you wouldn’t expect to
be able to walk into our Centre and use our computers or microscopes,
even if you were an Australian taxpayer. Now, processed data is in an
intermediate category — I think I would only provide that if I believed
that I (and therefore my paymaster, the Australian Government) was going to
benefit. If I sensed that providing such data would result in
interminable future questioning and wasting of my time, I certainly
wouldn’t provide it.
So — I guess the bottom line is, if someone asked me out the blue that
they wanted processed data or software so that they could “audit” it, I’d
probably say “no”. However if some spirit of collaboration was involved and
we could all benefit, then it would be a very different matter.
JohnH, you fall from grace. Steve’s post was temperate and corrected YOUR mistake. which was a mistake in your favor. You ought to have some grace and admit your error with a mild contrition. Feynman would not think much of your behavior.
I’m actually curious how the error occured. Were you just so sure in your mind that the text would support your view? What happened?
Note that both Steve and I commended you earlier for your insightful comments about the IPCC. You really fell down in my book.
Having just found this thread, I wanted to correct a couple of misconceptions.
First, John Hunter said:
a) “Contrarian”? I guess that must mean someone who disagrees with John Hunter.
b) John probably did not realize that both he and I specifically asked for our contributions to be peer-reviewed. It is worthwhile noting, however, that peer review has not kept a number of egregiously bad articles, both in and out of the climate field, from being published in scientific journals.
Second, John Hunter says:
However, he never says who made that statement, leaving the reader to infer that it was either John Daly or myself. To the best of my knowledge, John Daly did not say that, and I certainly did not do so.
John Hunter describes his reason for doing the research as:
He paints himself as a disinterested seeker after truth, when in fact, his research was undertaken at the specific request of Greenpeace. Here is a quote from Greenpeace:
Finally, what I discussed at length in my study published in E&E was not the exact sea level rise. It was the cause of the damage to the islands. Several of the islands of Tuvalu have experienced severe land loss and erosion. The Government of Tuvalu and Greenpeace claimed, and still maintain, that this damage was done by rising sea levels. Greenpeace asked John Hunter to do his study specifically to support this erroneous claim, and used it for that purpose.
However, nothing could be further from the truth than blaming the damage on rising seas. The damage, as shown by a very extensive coastal processes survey done by SOPAC, is a result of man-made changes in the reef and in the islands. That was the point, and the conclusion, of my paper.
In fact, my conclusion has recently been reinforced by a new study by SOPAC, which comes to the exact same conclusions that I highlighted in my paper — the problem is damage to the reef, not rising sea levels.
w.
The quote from Green Peace is a comment on JohnH’s work and it’s implications. It is not a statement that they requested the research.
Please stop the discussion about Greenpeace as though it had something to do with the merit of Hunter’s research. I don’t want to get into a slanging match about Greenpeace and will delete any further discussion of this topic.
My comment was not meant to be about Green Peas per se, but about Willis’s logic/communications.
Having just found this thread, I wanted to correct a couple of misconceptions.
First, John Hunter said:
a) “Contrarian”? I guess that must mean someone who disagrees with John Hunter.
b) John probably did not realize that both he and I specifically asked for our contributions to be peer-reviewed. It is worthwhile noting, however, that peer review has not kept a number of egregiously bad articles, both in and out of the climate field, from being published in scientific journals. There is good research published in non-peer reviewed journals, just as there is bad research published in peer-reviewed journals.
c) “Old hat”? Erroneous ideas about Tuvalu and sea level rise are still being published. In the last month, Google News finds eight new articles repeating the erroneous claims of Greenpeace and Hunter that Tuvalu’s erosion problems are due to sea level rise. Given that the actual cause of the erosion is known (see below), I can see why he might want to disassociate himself from his claims.
Second, John Hunter says:
However, he never says who made that statement, leaving the reader to infer that it was either John Daly, or myself, or perhaps some “contrarian”. To the best of my knowledge, John Daly did not say that, and I certainly did not do so. His claim is curious, however, because according to Hunter himself, at the time the best estimates of Tuvalu sea level rise were:
Thus, it would be hard to call these “careless claims”, they represented the state of the scientific knowledge at the time.
Third, John Hunter describes his reason for doing the research as:
He paints himself as a disinterested seeker after truth trying to quash incorrect claims, when in fact, according to Nature magazine, his research was undertaken at the specific request of Greenpeace. Nature said “And the international environmental group Greenpeace asked John Hunter, a climatologist at the University of Tasmania, to have another look at the data.”
Here is a quote from Greenpeace, along with their quotes from Hunter, about the research:
In my response to Hunters comments in E&E Volume 15 No. 5, I said “Given the Tuvalu Government’s threats to sue Australia and the US, with the support of Greenpeace and Hunter …”
John objected to this characterization, saying:
However, as the Greenpeace quote above clearly shows, he did in fact do much more than try to correct the science. He advocated taking action even though there was no evidence then (and none now) that sea level rise was the cause of the damage.
Finally, and most importantly, what I discussed at length in my study published in E&E was not the exact sea level rise. It was the cause of the damage to the islands. Several of the islands of Tuvalu have experienced severe land loss and erosion. The Government of Tuvalu and Greenpeace claimed, and still maintain, that this damage was done by rising sea levels. Greenpeace asked John Hunter to do his study specifically to support this erroneous claim, and used his research for that purpose.
However, nothing could be further from the truth than blaming the damage on rising seas. The erosion damage, as shown by a very extensive coastal processes survey done by SOPAC (Xue, C. (1996) Coastal Erosion And Management Of Amatuku Island, Funafuti Atoll, Tuvalu, 1996, South Pacific Applied Geoscience Commission (SOPAC), http://conf.sopac.org/virlib/TR/TR0234.pdf), is a result of man-made changes in the reef and in the islands. That was the point, and the conclusion, of my paper.
In fact, my conclusion has recently been reinforced by a new study by SOPAC (EU EDF 8/9 — SOPAC Project Report No: 54, Coastal change analysis using multi-temporal image comparisons — Funafuti Atoll, TUVALU, December 2005. This study, using photogrammetry comparing older and newer aerial photographs of the islands, came to the exact same conclusions that I highlighted in my paper — the problem is man-made changes to the reef, not rising sea levels.
And in a final telling point, according to the new SOPAC study the aggregate effect of the changes in the shapes of the various uninhabited islets of Tuvalu from 1984 to 2003 has been to increase the land area of these islets by 2.8% … hardly the sign of the claimed sea-level damage, which should have decreased the area.
w.
Can anyone tell me how I can read the 1990 and 1995 IPCC reports, preferably on line?
Aloha! eir
@ Ed,
Please don’t overstate (250 mm = approx 1 foot)
If you had said 350 mm = approx 1 foot it would have been ok.
If you look at the difference (which is approx, didnt check, 35% differnt)
So I don’t think I would like to be called up on that.
BTW I like most of your posts
Z
Sorry should have checked.
It should have been 305 mm = approx 1 foot.
So that would be approx 20% diff from 250mm ,still alot of difference.
The thing is its so easy to make a simple mistake 😦
But I will say sorry for it, and everyone can blame me for it.
Z