Defending my statements. Re. dana?

“Subject: defend your statements

Message: I have never once used Mann's hockey stick graph, and Hansen's 1988 climate predictions were quite accurate.

Prove otherwise.”

So, to prove I was correct, I’ll offer the following evidence.

Dana quotes Mann’s flawed hockey stick graph…

Unfortunately for dana he did this very thing in a very rare question that I asked! You can see the question here (sorry it’s so long and boring)… http://uk.answers.yahoo.com/question/index;_ylt=As...

In his answer, dana links to this… http://www.grida.no/climate/ipcc_tar/wg1/figspm-1.... Now, feel free to correct me if I’m wrong, but that’s the Mann hockey-stick graph, is it not?

So that’s point one proved.

Second, dana claims that Hansen’s predictions were “quite accurate”.

He’s toned it down since this question (http://uk.answers.yahoo.com/question/index;_ylt=Ag... ) where he describes them as “extremely accurate”.

My answer to that question fairly demolishes Hansen’s predictions and shows that they were not even remotely accurate and, in fact, the claim that they were is basically a lie.

Thus I feel I am correct in stating that dana is just as guilty of using questionable evidence to support his belief in man-made catastrophic global warming, as any sceptic is of doing the same to support the opposite view.

I believe the appropriate saying at this juncture would begin “People in glass houses…”

Comments?

So many errors, so little time. Where to begin. I suppose I’ll “begin at the beginning” (as the king said gravely)

Vasanth K: Er? Can I skim over this one?

afratta437: I tend to agree.

Anders: Interesting, but not a comment on my question.

Mr Jello: As Anders, above.

Paul H: A-ha! Here we go. I’m not going to get into yet another discussion regarding whether or not Mann’s “hockey-stick” graph was flawed; it’s a whole separate question. Ask it if you want to discuss it. If you want to read all about its problems have a look here… http://www.climatechangeissues.com/files/PDF/conf0... If you want to read the “best bit” start at the penultimate paragraph of page 10 and pay careful attention to figure 7 on page 11 showing 7 runs of Mann’s algorithm with random red noise and one with Mann’s actual data. Can you tell the “real” hockey-stick from the 7 “false” ones?

So, moving onto your comments about Hansen. I hadn’t read the article by Hansen in your third link, so thanks for that. There are several comments I’d like to make about it, but, again, that’s for another question. He doesn’t actually say very much in support of the suggestion that he was correct, other than simply showing the graph.

Interestingly, however, this is the exact same graph that was used on the page dana linked to, in the answer where I challenged the “Hansen was extremely accurate” view. So, the question immediately arises: While it is understandable that Hansen’s 1999 article has the observed temp line stopping in 1998 (as you later say, he would have needed a time machine to make it go further), why does the site dana linked to use it? They could, and I would argue should, keep their site up to date. Why do they have an eight year old graph supporting their claim? Again, is it because it looks better than an up to date one?

With regard to Patrick Michaels, it is important to remember that, until it became apparent in 2000 that Hansen’s scenario A was way out, *everybody* was quoting it as the almost certain outcome. This phenomenon of always quoting the worse-case scenarios is still apparent today; you can try it yourself by asking the question: “How much will sea levels rise by 2100?” I can almost guarantee that the answers you’ll get from the alarmists will be much greater than the IPCC’s average estimate of about 15 inches. Everyone always quotes the highest figure they can find, thus Michaels can be forgiven for attempting to disprove what everybody was quoting.

You then quote a graph and claim that “1988 had a temperature anomaly of ~0.2oC” Er? No, actually. I think you’re looking at the cold year of 1989! Remember, 1988 was a very hot year – it was actually the year before; that dot just above the 0.3°C, so shall we say 0.31°C? So that’s within 0.02°C of 2000 (which I’ll accept is about 0.33°C) or about 1/50th of a degree. Does 1/50th of a degree count as “close to” as I said in my answer?

Also note that you’re not quoting the satellite data as I did so we’re also arguing about which data source is more accurate. I firmly believe that the new satellite data is more reliable than the surface data given the latter’s problems with coverage and placement. (See… http://www.surfacestations.org/ )

I agree that comparing single years to each other is meaningless – I was just pointing out that that’s what a GWA would have done – had it been to their benefit (dare I ask how good Hansen’s graph would have looked had he smoothed 1998?)

And excuse me, I have never said that the trend post 1998 is “one of falling temperatures”. I mentioned that temperatures dropped like a rock in 1999 from the high of 1998, but I never even hinted at the suggestion that that was any kind of trend. I *have* said that there is no trend in temperature since 2002 and the graph you link to supports that conclusion.

And I disagree that there is still good agreement between data and model. Since most data records still have 1998 as their hottest year, the recorded temperature is falling further and further behind Hansen’s model. You can only claim differently if cherry-pick the one dataset that has 2005/2006 as “the hottest years ever”. Using the satellite data (arguably the most reliable record) we have barely surpassed Hansen’s 0.3°C today after 18 years.

Thus, based on your evidence I see no reason to retract any of my claims.

EnragedParrot: Hello again :) “Hockey-stick” – So you accept that it may have been a blatant lie, but you claim that that’s not important and I should continue to trust people who lied to me? LOL Don’t worry, I’m just baiting you, I’m happy to let it drop for the purposes of this question. The fact is dana linked to it, and to your next paragraph, no, we were discussing the MWP, and the top graph was the past 140 years, so it was definitely Mann’s graph he was referring to.

No, my basic arguments runs like this. Hansen said 0.45°C, 0.3°C or 0.25°C. Actual outturn was 0.14°C. Thus Hansen was wrong. Simple as that.

I was not trying to suggest that there’s been no warming since 1998. I *did* point out that temperatures dropped like a rock after 1998, back to around the temperature of 1988, but I never suggested that that was the start of a cooling trend, just that the graph wouldn’t have looked as good had he put those years in. I’ve subsequently learned (from Paul, above) that he created that graph in 1999, so Hansen can be forgiven, but I would argue that dana’s source should have used a graph that included the years 1999 and 2000. One has to ask the question why they haven’t, and I would suggest the answer is that they know damn well it won’t look as convincing. Wouldn’t you agree that that’s slightly dishonest?

Your next two paragraphs are moot, because you’ve misunderstood my point.

BTW, your graph: Are you sure about that 2001 plot? It can’t possibly be that high, can it? Oh, and even your graph shows no warming since 2002 – isn’t it exciting wondering whether it’ll go up or down next? LOL

Again where has this idea that I said that temperatures were trending down come from? My answer never once mentioned a downward trend, I simply pointed out, correctly, that temperatures dropped like a rock after 1998. Even your graph shows this: 1998 = ~0.58 2000= ~0.29. That’s almost all of Hansen’s Scenario B 0.3°C, in just two years. Under the circumstances I’d think that constitutes dropping like a rock.

Let me be very clear about this: I’m not suggesting that this drop in temperature implies anything about future temperatures. All I’m pointing out is that if you run the trend from ’88 to (the very host year of) ’98 you get a rise of 0.22°C. If you assume the trend will continue like that, you get a rise by 2000 of 0.26°C – very close to Hansen’s guess. These figures are very different from that actual figure of 0.14°C by 2000. Let’s face facts here, Hansen was very, very lucky we got that insanely hot 1998, because, without it, the observed figure would have been much lower. If we look at the ’88 – 97 trend (i.e. losing the very hot 1998) and project it to 2000, we get -0.02°C (note the minus!).

Do you see what I’m getting at now? Hansen… was… wrong.

Thus, dana’s evidence that Crichton was wrong is an error. I’ll accept that it was, perhaps, an honest error, because he didn’t know the truth. But he knows now, doesn’t he? So will he do it again?

Salomón II: As has been pointed out, the data you quote was for the US only, so has only limited reference to global temperatures.

The most interesting thing about this error is the fact that it was discovered by Stephen McIntyre. So, good old Steve was clever enough to spot the error that all climate scientists had missed, but, when he claims that the Mann “hockey-stick” graph is flawed, he’s just an idiot who should be ignored.

You’ve got to laugh at the GWAs, haven’t you?

And speaking of GWAs…

Bob: Well, *bits* of it were overly smoothed. Other bits were actively *encouraged* to rise. Hence even random data will produce a hockey-stick result.

I really don’t get this illogical defence of Mann’s graph. Let me say this yet again:

Random data will produce the same hockey-stick graph 99% of the time.

Am I missing something here? If I am, please explain it to me, because I can’t see it.

Again, here is what you need to read… http://www.climatechangeissues.com/files/PDF/conf0...

Another good quote (speaking of the bottom panel of Figure 6 in the document that shows a trendless line with no “up-tick” at the end) …

“…It shows what happens when Mann’s PC algorithm is applied to the NOAMER data after removing 20 bristlecone pine series. Without these hockey stick shapes to mine for, the Mann method generates a result just like that from a conventional PC algorithm, and shows the dominant pattern is not hockey stick-shaped at all. Without the bristlecone pines the overall MBH98 results would not have a hockey stick shape, instead it would have a pronounced peak in the 15th century

Of crucial importance here: the data for the bottom panel of Figure 6 is from a folder called CENSORED on Mann’s FTP site. He did this very experiment himself and discovered that the PCs lose their hockey stick shape when the Graybill-Idso series are removed. In so doing he discovered that the hockey stick is not a global pattern, it is driven by a flawed group of US proxies that experts do not consider valid as climate indicators. But he did not disclose this fatal weakness of his results, and it only came to light because of Stephen McIntyre’s laborious efforts.”

So Mann *knew* it was flawed!

So, your quote that “The big swing up is real…” is not actually true.

As to the later graphs supporting the suggestion that the MWP was cooler than today, well, call me paranoid, but I have my doubts. I’m not going to get into the whole argument again though, as you know, I asked a question about it and wrote reams and reams.

A-ha! The man himself.

Dana: Actually, I did try to reply, but Y!A said…

“Oops

You cannot send messages until you enable Yahoo! Answers email communications.”

At which point I thought “Er? Oh sod it, I’ll ask a question and work out what the heck that is later”

Sorry.

To your first point… One word… Thin.

I have a few problems with that train of thought - would the error bars (if they had them) on one of the more recent graphs, that *do* show a little MPW, have encompassed the current warming? In other words, you can’t take a graph that completely deleted the MWP and claim that it’s significant that the current warm period is not even with the error bars.

Whatever, we don’t want to get talking about the MWP again.

So what you’re basically saying is, you did it by accident. Fair enough.

BTW, I just loved your quote “So technically your claim was correct, but basically it was wrong.” Er? Okay. LOL

Hansen. Again, I disagree. It does not matter how many graphs you show me proving that the temperature is rising. No one disputes that. The question is: did it rise as much as Hansen guessed. And the answer to that question is: no.

I note with interest that the source for figure 3 in your link is a certain “James Hansen”. Now, I don’t know why, but that name rings a bell for some reason.

You don’t think that, perhaps, just maybe, there’s a slight, off-chance that he might be a teensy-weensy little bit unreliable as a source to confirm his own findings?

The only way you can get Hansen’s guesses to be “extremely accurate” is to use the GISS dataset, but do you think it is safe to use that dataset when it is maintained by, amongst others, James Hansen? Remember, this is the *only* dataset that has 2005/6 as warmer than 1998.

To be completely fair (and at the risk of shooting myself in the foot), let’s calculate the trends with two other surface station records: GHCN & HadCRUT3. (Let’s remember that these are surface station datasets and thus suffer from potential problems of placement and coverage)

Straightforward ’88 – ’00: GHCN= 0.26°C. HadCRUT3= 0.26°C.

’88 – ’98 then project to ’00: GHCN= 0.24°C. HadCRUT3= 0.31°C.

’88 – ’97 then project to ’00: GHCN= -0.07°C. HadCRUT3= 0.11°C.

So, both of these datasets give a value of 0.26°C, so that’s just within his Scenario C, but still well below his Scenario B. Thus I would again claim that Scenario B was not “extremely accurate”. You could claim that of C, but not B.

The lower result for the GHCN ’88 – ’98 figure was a surprise. I think it’s because it has ’90 as quite hot, only .06°C cooler than ’98, which reduces the slope. On HadCRUT3 ’90 was 0.34°C lower than ’98.