Defending my statements. Re. dana?
In answering those questions, I pointed out that dana himself was just as guilty of this, and cited as proof the fact that he has quoted the flawed Mann hockey stick graph and claimed that James Hansen’s 1988 guesses of how much temperature would rise by 2000 were “extremely accurate”.
Dana didn’t respond to me in the questions themselves, but subsequently contacted me direct with the following…
Message: I have never once used Mann's hockey stick graph, and Hansen's 1988 climate predictions were quite accurate.
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/ind...
In his answer, dana links to this… http://www.grida.no/climate/ipcc_tar/wg1... 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.
He’s toned it down since this question (http://uk.answers.yahoo.com/question/ind... ) 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…”
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.
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.
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 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.
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.
Your next two paragraphs are moot, because you’ve misunderstood my point.
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.
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?
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?
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...
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) …
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.
Dana: Actually, I did try to reply, but Y!A said…
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”
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
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.
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.