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| 5/25 |
| 2006/7/17-19 [Science/GlobalWarming] UID:43687 Activity:nil |
7/17 Subcommittee to Hold Global Warming Hearing
More on the Mann Hockeystick Fraud
http://energycommerce.house.gov/108/News/07142006_1989.htm
\_ The statistical argument is totally a red herring. That global
warming is occurring is completely obvious and is not disputed
by anyone credible. That there is a human contribution to
global warming is similarly not under serious dispute. Tools like
Wegman exist only to give the administration an excuse to avoid
doing anything about it. -tom
\_ This doesn't say it's a fraud. It just raises a couple of points
that don't even seem significant. Do you understand the significance
of their points? I think you are full of shit and your use of the
term "fraud" pretty much shows you to be a fool. Most of the points
are essentially statiticians whining about not being important
enough (in a paper written by statisticians).
\_ posted by jblack
\_ Yet another effort to deny global warming.
\_ What is wrong with challenging dogma? There are lots of reasons
to believe the earth is warming up but the Mann Hockeystick is
not one of them.
\_ UrlP
\_ http://energycommerce.house.gov/108/News/07142006_1989.htm
If you bothered reading the link instead of robotically
saying, "UrlP" everytime a statement is made that doesn't
match your _political_ views maybe, oh fuck it, nevermind.
What I find interesting about the global warming non-debate
is how many pro-GW scientists have zero background in
climatology and how so few of those who study the greatest
source of the planet's heat agree with or in many cases are
actively speaking out against GW, but I'm sure the folks
studying the sun are all just whack jobs.
\_ http://www.csua.org/u/gg3 (realclimate.org)
Or by all means rant and swear some more.
\_ So your link says what I said. Mann is garbage yet
we still have Gore making movies for public
propaganda purposes including it and yet where is
the scientific community (or the press) coming out
to say "no, no, no it isn't like that!"? It makes
for a very visually scary picture but isn't
statistically reliable yet based on that numerous
people on the street and in government see it and
want to make dramatic policy shifts based on it.
Madness. Thanks for the link backing what I said.
\_ Neither your link nor mine backs what you said.
You are frothing.
\_ I read both. They do. Whatever. And really,
just because someone says you're wrong does
not mean they are frothing, ranting, or
any other personal attack you'd like to spam.
Gosh, maybe they just disagree with you? What
is the point of putting in personal attack
anyway? It doesn't make you look smarter.
\_ Your frothiness has nothing to do with
whether pp was incorrect; you're still
frothing. Take a deep breath and point to
points.
\_ Anytime you'd like to make a point and
stop making empty personal attack I'll
be there to chat with you. Like I said,
"whatever". If that's frothy, you must
be really 'sensitive'. That's not my
problem. The link quite clearly states
that Mann is nonsense and they'd like to
put the hockey stick behind them because
the failure of the science behind the
hockey stick chart is distracting from
their real message. These guys are
looking to move forward while some people
here are stuck on defending a broken
chart. My point is right there in the
link. Your point is... not here. If
you'd like to make one, I'll be around.
\_ Have you actually *looked* at realclimate? They
are pretty firmly in the "global warming is real"
camp.
\_ Yep, I read it all the time. Have you read it?
Have you read the link I posted?
\_ I know you are, but what am I?
\_ I'm sticks and you're stones and ... oh
wait, that's not right. Hmmmm.... |
| 5/25 |
|
| energycommerce.house.gov/108/News/07142006_1989.htm Stay Informed Search Go Subcommittee to Hold Global Warming Hearing Witnesses to Testify on Climate Change Assessment Report WASHINGTON - US Rep. Edward Wegman will present his panel's report but a full witness list has not yet been finalized. About the Wegman report: It is important to note the isolation of the paleoclimate community; even though they rely heavily on statistical methods they do not seem to be interacting with the statistical community. Additionally, we judge that the sharing of research materials, data and results was haphazardly and grudgingly done. In this case we judge that there was too much reliance on peer review, which was not necessarily independent. Moreover, the work has been sufficiently politicized that this community can hardly reassess their public positions without losing credibility. Michael Mann, et al, formed the basis for the IPCC assessment's conclusion that the increase in 20th century Northern Hemisphere temperatures is "likely to have been the largest of any century during the past 1,000 years" and that the "1990s was the warmest decade and 1998 the warmest year" of the millennium. Questions about the reliability of the Mann studies were of interest because they raised policy-relevant questions concerning the objectivity of the IPCC and its reliance upon and "promotional" use of the studies' hockey stick' shaped historical temperature reconstruction. Following receipt of the letter responses, committee staff informally sought advice from independent statisticians to determine how best to assess the statistical information submitted. Edward Wegman, a prominent statistics professor at George Mason University who is chair of the National Academy of Sciences' (NAS) Committee on Applied and Theoretical Statistics, agreed to independently assess the data on a pro bono basis. Wegman is also a board member of the American Statistical Association. Wegman assembled a committee of statisticians, including Dr. All worked independent of the committee, pro bono, at the direction of Wegman. In the course of Wegman's work, he also discussed and presented to other statisticians on aspects of his analysis, including the Board of the American Statistical Association. Wegman's analysis concludes that Mann's work cannot support claim that the1990s were the warmest decade of the millennium. Report: "Our committee believes that the assessments that the decade of the 1990s was the hottest decade in a millennium and that 1998 was the hottest year in a millennium cannot be supported by the MBH98/99 analysis. As mentioned earlier in our background section, tree ring proxies are typically calibrated to remove low frequency variations. The cycle of Medieval Warm Period and Little Ice Age that was widely recognized in 1990 has disappeared from the MBH98/99 analyses, thus making possible the hottest decade/hottest year claim. However, the methodology of MBH98/99 suppresses this low frequency information. The paucity of data in the more remote past makes the hottest-in-a-millennium claims essentially unverifiable." Report: "It is clear that many of the proxies are re-used in most of the papers. It is not surprising that the papers would obtain similar results and so cannot really claim to be independent verifications." Report: "As statisticians, we were struck by the isolation of communities such as the paleoclimate community that rely heavily on statistical methods, yet do not seem to be interacting with the mainstream statistical community. The public policy implications of this debate are financially staggering and yet apparently no independent statistical expertise was sought or used." Report: "Especially when massive amounts of public monies and human lives are at stake, academic work should have a more intense level of scrutiny and review. It is especially the case that authors of policy-related documents like the IPCC report, Climate Change 2001: The Scientific Basis, should not be the same people as those that constructed the academic papers." Federal research should involve interdisciplinary teams to avoid narrowly focused discipline research. Report: "With clinical trials for drugs and devices to be approved for human use by the FDA, review and consultation with statisticians is expected. Indeed, it is standard practice to include statisticians in the application-for-approval process. We judge this to be a good policy when public health and also when substantial amounts of monies are involved, for example, when there are major policy decisions to be made based on statistical assessments. In such cases, evaluation by statisticians should be standard practice. This evaluation phase should be a mandatory part of all grant applications and funded accordingly." Report: "While the paleoclimate reconstruction has gathered much publicity because it reinforces a policy agenda, it does not provide insight and understanding of the physical mechanisms of climate change... What is needed is deeper understanding of the physical mechanisms of climate change." |
| www.csua.org/u/gg3 -> www.realclimate.org/index.php/archives/2006/06/national-academies-synthesis-report/#more-316 NAS synthesis report on surface temperature reconstructions over the last few millennia is being released today. It's a long (155 page) report and will take a while to digest, but we applaud the committee for having tried to master a dense thicket of publications and materials on the subject over a relatively short time. It is probably expecting too much for one report might to put to rest all the outstanding issues in a still-developing field. And given the considerable length of the report, we have little doubt that keen contrarians will be able to mine the report for skeptical-sounding sentences and cherry-pick the findings. However, it is the big picture conclusions that have the most relevance for the lay public and policymakers, and it is re-assuring (and unsurprising) to see that the panel has found reason to support the key mainstream findings of past research, including points that we have highlighted previously: 1) The authors of the report accurately report the considerable uncertainties that were acknowledged by seminal earlier studies. Mann et al 1999, which was entitled (emphasis added) "Northern Hemisphere Temperatures During the Past Millennium: Inferences, Uncertainties, and Limitations, emphasized the uncertainties and caveats, particularly with regard to reconstructing large-scale surface temperature patterns prior to about AD 1600 The report makes due note of this (pg. large-scale surface temperature reconstructions were the first to include explicit statistical error bars, which provide an indication of the confidence that can be placed in the results. work, the error bars were relatively small back to about AD 1600, but much larger for AD 1000-1600. The lower precision during earlier times is caused primarily by the limited availability of annually resolved paleoclimate data: That is, the farther back in time, the harder it is to find evidence that provides reliable annual information. For the period before about AD 900, annual data series are very few in number, and the non-annually resolved data used in reconstructions introduce additional uncertainties. substantiated by many other studies, and the confidence in those conclusions appears greater, not lesser, after nearly an additional decade of research (pg. This conclusion has subsequently been supported by an array of evidence that includes the additional large-scale surface temperature reconstructions and documentation of the spatial coherence of recent warming described above (Cook et al. Based on the analyses presented in the original papers by Mann et al. and this newer supporting evidence, the committee finds it plausible that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium. irrespective of whether or not the original "hockey stick" is correct. The report makes repeated note of this key point, for example on page 4 of the report: Surface temperature reconstructions for periods prior to the industrial era are only one of multiple lines of evidence supporting the conclusion that climatic warming is occurring in response to human activities, and they are not the primary evidence. and again on page 9 of the report: The reconstruction produced by Dr. Mann and his colleagues was just one step in a long process of research, and it is not (as sometimes presented) a clinching argument for anthropogenic global warming, but rather one of many independent lines of research on global climate change. here) issues with regard to the strengths and weaknesses of alternative paleoclimate proxy reconstruction methods it was encouraging, for example, that the authors of the report favor the use of some combination of the standard measures of the fidelity or "skill" of paleoclimate reconstructions ("RE" and "CE") generally used by paleoclimate researchers, and dismiss as without merit the use of simple correlation coefficients , and 4 move beyond the often inappropriate focus given to hemispheric mean temperature, and give greater future attention to the detailed spatial patterns of past temperature changes, as well as reconstructions of precipitation and atmospheric circulation variables. While we agree with the bottom-line conclusions in the report, this is not to say that we don't also have some criticisms: The report provides an unbalanced discussion of some significant technical details. For example, there is quite a bit of discussion of possible biases involved in centering conventions used in Principal Component Analysis (PCA). Yet the report only vaguely alludes to the fact that published work see both Wahl and Ammann (2006) and Rutherford et al (2005) cited in the report clearly demonstrates that this doesn't introduce any significant bias as long as statistically significant patterns in the data are not discarded. The report calls into question the confidence in certain fairly specific previous conclusions, eg the tentative conclusion in Mann et al (1999) that the 1990s and 1998 were the warmest decade and year, respectively, of the past 1000 years. There are two important points here left unmentioned in the report: Mann et al (1999) attached the qualifier "likely" to these conclusions, which in standard (eg IPCC) parlance corresponds to a roughly 2/3 probability, ie, implies slightly better than even odds of being true, a fairly conservative conclusion. The conclusions regarding the decade of the 1990s and the year 1998 follow from reasonable assumptions. The late 20th century Northern Hemisphere average warmth, according to Mann et al (1999) and all subsequent studies, appears anomalous in at least the past 1000 years. So the base state about which higher-frequency (eg interannual) fluctuations occur was substantially higher at the end of the late 20th century then during any earlier comparable period. Unless the interannual fluctuations in hemispheric mean temperature during earlier centuries were significantly greater in amplitude than during the 20th century (and there is no obvious evidence that they were), then it reasonably follows that the thresholds reached during the 1990s or during 1998--an anomalously warm decade and year respectively from the perspective of the instrumental record--are unlikely to have been breached in earlier centuries. independent study not cited, but published well before the report was drafted, comes to very different conclusions. This reflects one of a number of inevitable minor holes in this quickly prepared report. before the importance of making sure that the press will be able to correctly contextualise a release and the bad consequences of that not happening. Well, in this case the press release annoucing the publication of the report was often inconsistent with what was actually stated in the report. It was titled: 'High Confidence' That Planet Is Warmest in 400 Years; Less Confidence in Temperature Reconstructions Prior to 1600 which is not news at all and almost trivially true. However, it is likely to be mis-interpreted to imply that there is no confidence in reconstructions prior to 1600, which is the opposite of the conclusion of the report. Additionally, the text appears to have confused the key distinction between our knowledge of global mean temperature in past centuries (which is very limited owing to the sparseness of long available proxy data in the Southern Hemisphere, and for which a reconstruction was not attempted by Mann et al or most other researchers), with our knowledge of Northern Hemisphere mean temperature (which is considerably better; Finally, it is worth pointing out and emphasising that the report provides absolutely no support for the oft-heard claims that the original hockey stick was the result of 'programming errors', or was 'not reproducible', or there was some scientific misconduct involved. These claims were always spurious and should now finally be laid to rest. Hopefully, we can all start to move forward with the science again. the committee finds it plausible that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the pr... |
| realclimate.org Climate Science -- group @ 12:45 pm Anybody who has followed press reporting on global warming, and particularly on its effects on hurricanes, has surely encountered various contrarian pronouncements by William Gray, of Colorado State University. here by CNN), provides an illuminating window into Gray's thinking on the subject. Our discussion is not a point-by-point rebuttal of Gray's claims; there is far more wrong with the paper than we have the patience to detail. Gray will have plenty of opportunities to hear more about the work's shortcomings if it is ever subjected to the rigors of peer review. Here we will only highlight a few key points which illustrate the fundamental misconceptions on the physics of climate that underlie most of Gray's pronouncements on climate change and its causes. Gray's paper begins with a quote from Senator Inhofe calling global warming a hoax perpetrated on the American people, and ends with a quote by a representive of the Society of Petroleum Geologists stating that Crichton's State of Fear has "the absolute ring of truth." It is the gaping flaws in the scientific argument sandwiched between these two statements that are our major concern. documentary on the possible over-selling of climate change, focussed on the link between high profile papers appearing in Nature or Science, the press releases and the subsequent press coverage. The press coverage of the paper mostly picked up on the very high end sensitivities (up to 11-oC) and often confused the notion of an equilibirum sensitivity with an actual prediction for 2100 and this lead to some pretty way-out headlines. I think all involved would agree that this was not a big step forward in the public understanding of science. Is it because the scientists were being 'alarmist', or was it more related to a certain naivety in how public relations and the media work? And more importantly, what can scientists do to help ensure that media coverage is a fair reflection of their work? The Big Burp Theory of the Apocalypse (TimesSelect subscription required), which appeared in the New York Times of 18 April. This column is built around the possibility of a catastrophic methane release from marine clathrate decomposition, but at heart it is really a lament that the more conventional and better understood harms of global warming have not proved sufficient to get the attention of the White House or Congress. This column is a refreshing change from the recent spate of backlash columns by Will, Novak and Lindzen attempting to tar climate scientists with the "a****mist" epithet. Dave Archer's RealClimate article on clathrates, and it shows in the Kristof's sound discussion of the basic science. He is very clear on why a clathrate catastrophe would be a bad thing, but equally clear about the uncertainties. The column even contains an intelligent discussion of the Paleocene-Eocene Thermal Maximum as a possible example of a clathrate catastrophe. taking care to point out that this event might not, in fact, have been caused by methane release. Quite a lot to get in a short column, while still managing to achieve a lively style that surely keeps the readers awake. Perhaps closest to our hearts is Kristof's cogently stated theme that uncertainty is in the nature of the science, and is no excuse for inaction -- indeed should be a spur to greater action. "The White House has used scientific uncertainty as an excuse for its paralysis. But our leaders are supposed to devise policies to protect us even from threats that are difficult to assess precisely -- and climate change should be considered even more menacing than a nuclear-armed Iran." He concludes, "The best reason for action on global warming remains the basic imperative to safeguard our planet in the face of uncertainty, and our leaders are failing wretchedly in that responsibility." Kristof is a 2006 winner of the Pulitzer Prize for commentary. Some of this solar energy is reflected back out to space and this cooling effect is believed to have counteracted part of the greenhouse gas warming. The original version of the film focused mainly on the observational recognition of global dimming, but one aspect did not receive much attention in the film - namely the oft-claimed lack of global dimming in climate models. This led some to assume that climate modelers were ignoring air pollution other than greenhouse gases emissions from fossil fuel burning. Another implication was that climate models are not capable of adequately simulating the transfer of sunlight through the atmosphere and the role of clouds, sunlight extinction of aerosols and aerosol effects on clouds etc, and therefore model projections should not be trusted. The NOVA version will address this issue more prominently by adding an interview with Jim Hansen from NASA Goddard Institute for Space Studies. Along this line, I'd like to elaborate on aerosols in climate models in more detail. It deserves to be more widely seen, so here it is again. I would say that the central flaw in the op-ed is a logical one: if you're trying to stifle dissent, then you want less funding for climate research, not more. If you're trying to stop global warming, then you want more money for carbon sequestration research, and you don't care how much is spent on climate research. On the other hand if you just love climate research as a really interesting intellectual pursuit, that's when you've got an interest in shedding doubt on the reigning view that CO2-induced climate change is a serious policy program, requiring action. Twenty-five years ago, when global warming wasn't a big public worry, one might expect climate change researchers to hype the problem. In 2006, when public opinion mostly accepts that there's a problem, scientists who want research money should be emphasizing uncertainty. previously pointed out that there is no evidence whatsoever that 'alarmism' improves anyone's chances of getting funded - if anything it is continued uncertainty that propels funding decisions, and secondly, the idea that there is a conspiracy against contrarian scientists is laughable. There is indeed a conspiracy against poor science, but there is no need to apologise for that! But rather than repeat ourselves once again, we thought we'd just sit back this time and allow our readers to comment... Greenhouse gases -- rasmus @ 1:22 pm by Rasmus Benestad and Ray Pierrehumbert Venus Express will make unprecedented studies of the largely unkown phenomena taking place in the Venusian atmosphere. European Space Agency (ESA) mission to probe the the atmosphere of Venus and address questions regarding the differences between the climates on Venus and Earth. According to the plans, the probe will enter the final orbit around Venus in May 2006, ie within about a month. Primarily, Venus offers scientists the chance to see how the same basic physics used to study Earth's climate operates under a very different set of circumstances. rather similar to Earth: it has nearly the same mass as Earth, and while its orbit is somewhat closer to the Sun, that effect is more than made up for by the sunlight reflected from Venus' thick cloud cover. Because of the cloud cover, the surface temperature of Venus would be a chilly -42C if were not for the greenhouse effect of its atmosphere. "false objectivity of balance", ie the tendency for many journalists to treat scientific issues--for which differing positions often do not have equal merit-- in the same "he said, she said" manner they might treat a story on policy or politics. This approach can appear balanced, but it leaves it to the reader to figure out on their own which position is most likely correct. However, the reader is rarely as well equipped as the writer to determine the bottom line, and in practice this plays into the hands of those who might seek to confuse the public through clever disinformation campaigns. Thankfully, some journalists "get it", and take the time (and effort) to assess where the balance of evidence really lies and report it accordingly. Climate Science -- gavin @ 11:45 am One of the nice things about a being a scientist is that you c... |