http://thinkprogress.org/romm/2011/08/22/300821/nsf-inspector-general-investigation-michael-mann/
The Hockey Stick has been independently investigated so many times it’s not funny, and every single time, Mann, et al. have come out smelling like roses.
The Hockey Stick is a real phenomenon, people. Global warming is a real phenomenon, and we’re causing it.
Yeah, color me unsurprised. I don’t doubt that the deniers will find some way to ignore it.
The scary thing is that the climate change deniers are not only most of the GOP but also most of the GOP presidential candidates:
I’m just baffled at why deniers have such a problem with it. Besides being anti-science, I don’t see how it fits with GOP ideals.
Because it unequivocally says that we must must must stop using fossil fuels, and there’s a shit-ton of profit tied up with fossil fuels. They deny because of money. it’s pretty much that simple.
Besides that:
[ul]
[li]It threatens corporate profits in the short term - and these people only think short term. It doesn’t matter to them that it’ll cost more in the long run to let things go to hell or that we need to upgrade & repair our infrastructure anyway.[/li]
[li]Fundy Christianity. Many think that the world will end soon anyway so there’s no reason to worry, or actively desire as great a disaster as possible because they think that will bring Jesus back sooner.[/li]
[li]The left supports it, therefore they oppose it.[/li]
[li]It amounts to concern over someone and something besides themselves, and they not only don’t care about others but are ideologically devoted to not caring.[/li][/ul]
Well, you’d think if it was all about money they’d realize what a mint could be made getting in early on renewable energy technology, but perhaps, as Der Trihs says, it’s all about short-term profit.
Global Warming would require a large green energy industry which would create jobs and possibly sap profits away from big oil, coal and gas. The GOP is very anti-job creation for some reason.
Denying GW allows big oil, coal and gas to keep polluting while increasing profits with minimal job creation or serious competition.
If I’m reading your link correctly, Mann has been cleared of ethical or scientific wrongdoing, which doesn’t surprise me. That is not exactly a vindication of the Hockey Stick, which is a more complicated matter.
Agreed.
Again agreed, but Mann et. al.'s hockey stick did not prove this, and criticisms of the hockey stick do not disprove it. The 20th Century temperature records and the latter 20th Century satellite records demonstrate global warming quite happily. The important part of the hockey stick isn’t the “blade”, which consists of modern temperature measurements, but the “stick”, which is a purported temperature reconstruction over the past 1000 years or so, put together from a variety of temperature proxies. Mann’s 1999 hockey stick published in the IPPC Third Assessment Report (TAR) showed far less natural variation in temperatures than had previously been believed, pretty much eliminating the medieval warm period that had featured in the First Assessment report.
We’re certainly causing some of it, and probably most of it. Again, the hockey stick doesn’t prove or disprove this. The controversy is how well the temperature over the last 1000 years has been reconstructed from tree rings and other other temperature proxies.
Now, onto Mann’s hockey stick, and “vindication.” Manns’s 1999 hockey stick from the TAR is shown here: http://en.wikipedia.org/wiki/File:Hockey_stick_chart_ipcc_large.jpg
Mann and his team have not been idle since then however, refining their data sources and statistical methods. Their latest take on the hockey stick AFAIK is this review from 2008: http://www.ncdc.noaa.gov/paleo/pubs/mann2008/mann2008.html Much of the historic variation has come back, and the medieval warm period also seems to be back.
From Mann’s own abstract: “Our results extend previous conclusions that recent Northern Hemisphere surface temperature increases are likely anomalous in a long-term context. Recent warmth appears anomalous for at least the past 1,300 years whether or not tree-ring data are used. If tree-ring data are used, the conclusion can be extended to at least the past 1,700 years, but with additional strong caveats. The reconstructed amplitude of change over past centuries is greater than hitherto reported, with somewhat greater Medieval warmth in the Northern Hemisphere, albeit still not reaching recent levels.” Italics are mine. That little phrase to me reads as an admisison that the 1999 hockey stick suppressed the hstorical temperature variation somewhat. That’s not an accusation of shenanigans or incompetence - it’s simply the way science works. His first analysis, the iconic and much-reproduced hockey stick, wasn’t entirely right.
But there’s more. Mann’s most recent hockey stick had the problems of incorporating tree ring data, which some regard as unreliable, and the Tiljander proxies, which may have a contamination problem. These difficulties were addressed by Gavin Schmidt of Nasa (the main man behind Realclimate and a died-in-the-wool global warming activist) on journalist Keith Kloor’s blog, here: DUNIA303: Situs Judi Slot Online Paling Gacor Terpercaya Terbaik (see comment 5 onwards). Part of his response was to link to a graph of supplementary work by Mann et. al on their 2008 paper, shown here: http://www.meteo.psu.edu/~mann/supplements/MultiproxyMeans07/NHcps_no7_v_orig_Nov2009.pdf
The supplementary work shows Mann’s hockey stick (black line plus red instrument measurement line) and also a green line (hockey stick without the Tiljander data) and a dark blue line (hockey stick without tree rings.) The blue line and green line show virtually no changes in relation to the original, showing that those putative problematic tree rings and Tiljander data make little difference when individually removed. That was Gavin Schmidt’s point. However, also present is a light blue line showing what happens when you remove both those controversial data sets together, and to my eyes at least it looks like the variance increases substantially and the Medieval Warm period gets a whole lot warmer.
To me, it looks like Mann has openly acknowledged that the historical climate record contains rather more natural temperature variation than his first hockey stick implied, and his supplementary work to his 2008 paper shows that that variation is even larger if you eliminate two questionable data sets from the reconstruction. Dopers can compare the graphs, read the abstract and draw their own conclusions.
All of this has very little to do with modern warming or what our current energy policy should be, and the upshot may simply be that we can’t determine the global temperature over the past 1000 years with any degree of precision. I don’t see why that should even be surprising, and it’s a source of some irritation to me that the whole thing became so very political.
Yes, but the attack on Mann was pretty much 100% about trying to discredit the entire basis of the idea of Global Warming by discrediting one of its main studies.
Yeah. Stupid politics. Too much was made of the current warming being “unprecedented”, and still is. I believe it was climate physicist Ed Zorita who said that if you eat six pizzas and get a stomach ache, it would be foolish to dismiss it as “natural” because stomach aches have happened in the past. It doesn’t matter if it’s unprecedented or not! The hockey stick was pounced on as a magic bullet against the argument of natural variation, and so had to be rabidly attacked by one side and defended to the death by the other, when the whole debate shouldn’t be a matter of “sides” at all.
Mann’s hockey stick was IIRC the first attempt at a multiproxy study, trying to tease information out of very noisy data. I have heard the iconic 99 hockey stick referred to somewhat unkindly as pure noise averaged into a straight line with the instrument data spliced on the end. Harsh, but looking at the error margins on http://en.wikipedia.org/wiki/File:Hockey_stick_chart_ipcc_large.jpg, there may be an element of truth in that. It still pioneered the more sophisticated reconstructions that have followed, though.
But that is then ignoring that the evidence points to the tree rings as having a problem only on the recent decades.
Of course as a commenter at Skeptical Science said once:
“However, I wouldn’t get carried away on paleoclimate - its skeptic fun park because of the uncertainty. AGW is founded in physics but tested against paleoclimate.” And what it is clear to me is that uncertainty goes both ways, one point I made in many discussion in the past was that the more skeptics attempt to make the proxies to be flawed or that it is impossible to make adjustments, that then it should mean that skeptics should also be **uncertain **that the medieval warm period was warmer than what we have today.
Of course Mann and others also offer other reasons why one should doubt that the medieval warm period was a global thing:
Mann’s 2008 paper has an interesting take on this on page 13254 - “the divergence problem is not limited purely to tree ring data, but instead may extend to other proxy records.” http://holocene.meteo.psu.edu/shared/articles/MannetalPNAS08.pdf
If that is the case, then using proxies to validate each other against the divergence problem becomes something of a problem in itself! The other question is if the tree rings track closely with other proxies, why did the removal of tree rings and Tiljander from Mann’s 40-odd other non-tree-ring data series change the graph so significantly?
I think the paleoclimate work is interesting, but still needs to be taken with a pinch of salt and only tangentially relevant to climate research today.
Once again, it is a recognized problem… for the last 40 years or so. Not so for the mess of past previous years.
But then again, why then be still so certain of the medieval warm period? The thing here is that I know the history, the very first proxy reconstruction had a big medieval warming period (and this was recognized by early IPCC reports) one big reason why deniers screamed to high heaven was that Mann and others became party poopers to a very cherished idea. (That early reconstruction was also given to them by the IPCC, go figure why they accepted that early reconstruction with very little skepticism)
The diagram from the first IPCC report doesn’t appear to have been a proper proxy reconstruction at all and only applied to central England. IPCC update temperature graphs with best available data The Medieval Warm Period was more a matter of recorded European history (grapes and other temperate crops being grown at high latitudes, treelines moving up mountains, settlement at higher altitude etc.) and archaeology than the result of a quantified proxy reconstruction. I certainly learned about it in school in the 70s and 80s when global warming was well below the public radar. The TAR hockey stick didn’t seem so much party pooping on a cherished idea as out-and-out revisionist history, with an agenda behind it.
Now possibly the Medieval Warm Period was confined to Europe, or at least the northern hemisphere, and maybe it wasn’t even all that much warmer on average. But after Mann’s 99 hockeystick the whole thing was dismissed for a while as the invention of untruthful Vikings or something. More recent reconstructions have brought it back again to some extent, see Mann’s own quote here (Medieval Warm Period - Wikipedia). as I showed upthread, Mann’s supplementary work shows a hockeystick using non-dendro proxies that has a pronounced MWP with temperature amplitude approaching current levels. That’s probably an artefact but I’m more inclined to accept some form of MWP than reject it, not because I trust tree rings in one case but not the other but because it fits better with archaeological evidence.
It says nothing of the sort. There is a large chasm between “Man-made global warming is real”, and “we must stop using fossil fuels”. We haven’t even begun to have that debate. The entire debate is stalled on the basic science, and the Republicans are on the wrong side of it. But once you get past that, there are plenty of questions left, and those questions are not as easily or clearly answered.
I was talking about the deniers that peppered the SDMB, they did indeed point at that early graph as the one that was supposed to be best that there was… well it was then, the problem was the march or science and the agenda of the deniers was clear then.
As the experience of previews discussion showed me, I do see that there was a medieval warm period, but it was mostly an European phenomenon, not global. In other words I do not reject it, just that when one takes it into perspective one realizes that it is very silly to base arguments against AGW based on it. Once again, I’m referring here to the local deniers, not the skeptics.
Not sure how this fits in here, but have you guys seen this article?
Yahoo news link on NASA Satellite data.
University of Alabama Press release
Basically, a researcher from the University of Alabama studied data from NASA’s Terra satellite and found that the atmosphere was holding far less heat than models had predicted. He published his findings in a peer-reviewed journal, Remote Sensing.
Not really sure where I fall in all this, so I won’t comment, just wanted to point this article and paper out.
Bear in mind that the Yahoo! link is to an editorial by an anti-AGW lobbyist, and the University of Alabama researcher behind the findings is… somewhat less than agnostic on the issue of global warming.
