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Comments 55951 to 56000:

55951. LarryM at 04:16 AM on 31 July 2012
       2012 SkS Weekly Digest #30
       I haven't read the Watts paper, and probably won't at this time because it hasn't even been submitted to a reputable peer-reviewed journal yet, so at present it has little more scientific credibility than a blog post or an editorial opinion. I suppose SkS will need to comment on it because the paper's advocates will attempt to make a mountain out of an unpublished molehill, but let's not forget that it's not a real paper until it has been revised to address the comments of expert reviewers and an editor, and accepted for publication.
55952. zinfan94 at 02:01 AM on 31 July 2012
       2012 SkS Weekly Digest #30
       Dana, I have a suggestion that you might keep in mind as you read Watts et. al. draft paper (copied from my comments at Stoat): One thing that really puzzles me about the Watts et. al. draft paper. Isn’t it important in scientific papers to address any prior work that clearly contradicts the current findings? Menne et. al. (2010) did a comparison of the best quality CONUS temperature measurement stations (USCRN) with the USHCNv2 stations. ( Menne paper Figure 7). The USCRN stations have been engineered to provide much more robust and error-free temperature recording and monitoring (three duplicate temperature sensors, isolated sites, consistent designs at every station, additional monitor supervision). Menne et. al. found that the USCRN temperature anomalies correlated extremely well with the USHCNv2 anomalies (r2=0.998 for Tmax and r2=0.996 for Tmin). Now Watts et. al. comes along, and claims that the USHCN is significantly in error against the station subset of only 48 Class 1 sites, and 112 Class 2 sites that he personally selected. The USCRN has 107 locations with 114 monitoring stations (seven stations are duplicated nearby). All of the USCRN stations would likely be considered Class 1 or better using the methodology in Watts et. al. And they were sited across the country to capture the CONUS anomalies accurately. So why didn’t Watts et. al. correlate their USHCN subset results (using the methodology applied in their paper) against the USCRN stations? Essentially the USCRN is the “gold standard” for siting, so the lack of the comparison in Watts et. al. sticks out like a sore thumb. If nothing else, this is an extremely important quality control exercise to ensure that obvious mistakes weren’t made processing the data from the USHCN subset stations. (next comment) To say what I meant in the last comment, a bit more succinctly: Isn’t Watts et. al. claiming (indirectly, given the Menne et. al. 2010 results that show excellent correlation between the USCRN and USHCNv2) that the US Climate Reference Networks stations are substantially in error? If so, this is an extraordinary result. NOAA needs to find out what is wrong with their state-of-the-art network ASAP.
55953. cynicus at 21:11 PM on 30 July 2012
       Peter Hadfield takes on the MWP
       @14 See first hit in Google Scholar after searching for "cenozoic himalaya ruddiman".
55954. chriskoz at 21:00 PM on 30 July 2012
       Peter Hadfield takes on the MWP
       JohnMashey@10, I'm not interested in MWP hypothesis by Ruddiman. I'm interested in another one Ruddiman's famous for: Tibet and Himalayan uplift speeding up igneous rock weathering and creating the late Cenozoic cooling. I canot find the original article (perhaps still hidden behind paywall), nor the comprehensive review of the state of the art here. Do you have a ready pointer or a suggestion where to search?
55955. heijdensejan at 17:21 PM on 30 July 2012
       2012 SkS Weekly Digest #30
       Victor Venema also has his first review of the new Watts paper http://variable-variability.blogspot.in/2012/07/blog-review-of-watts-et-al-2012.html
55956. Steve Bloom at 16:39 PM on 30 July 2012
       2012 SkS Weekly Digest #30
       Don't forget to have a look at Leroy's paper (peer-reviewed? and where is the data supporting the standards?). Consider the Class 3 temp standard, a key break-point for Watts: "Class 3 (additional estimated uncertainty added by siting up to 1 °C) • Ground covered with natural and low vegetation (< 25 cm) representative of the region. • Measurement point situated: o at more than 10 m from artificial heat sources and reflective surfaces (buildings, concrete surfaces, car parks etc.) o at more than 10 m from an expanse of water (unless significant of the region) o away from all projected shade when the Sun is higher than 7°. A source of heat (or expanse of water) is considered to have an impact if it occupies more than 10 % of the surface within a circular area of 10 m surrounding the screen or makes up 5% of an annulus of 5m." So if you have, e.g., a station that meets all Class 1 requirements except for having a ~1.5m shrub at a distance of 10m such that the aforementioned 7 degree standard (which note is relative not to the sensor itself but to the point on the ground directly below) is exceeded for even a few days each year, that's enough for a demotion all the way to Class 4. I'm tempted to blame Leroy for facilitating this stupidity, but of course his expectation is that the standards will be used by scientists, not propagandists.
55957. Rob Painting at 16:21 PM on 30 July 2012
       2012 SkS Weekly Digest #30
       The cartoon is spot-on..........sadly.
55958. Sceptical Wombat at 16:08 PM on 30 July 2012
       Peter Hadfield takes on the MWP
       Mercpl @3 I admire your optimism
55959. skywatcher at 14:31 PM on 30 July 2012
       2012 SkS Weekly Digest #30
       To paraphrase Darwin, "A house burned down by fire did not tell its story more plainly than did this atmosphere (or planet!). On Watts, he seems to have forgotten some sentiments of his about press releases before peer review
55960. skywatcher at 14:12 PM on 30 July 2012
       Peter Hadfield takes on the MWP
       #11: Muller's plying catch-up with the science. According to Mann, he's reached about the 1990s in his understanding of the science:

       "Some additional thoughts about Muller and 'BEST': Muller's announcement last year that the Earth is indeed warming brought him up to date w/ where the scientific community was in the the 1980s. His announcement this week that the warming can only be explained by human influences, brings him up to date with where the science was in the mid 1990s. At this rate, Muller should be caught up to the current state of climate science within a matter of a few years!" (source)

55961. Sceptical Wombat at 13:32 PM on 30 July 2012
       Peter Hadfield takes on the MWP
       Bill @ 1 Muller now accepts that global warming has been happening, is continuing and is almost entirely CO2 induced. He appears to be saying that there is no evidence that it is a particularly big problem.
55962. John Brookes at 13:32 PM on 30 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Ahh. You could have started off asserting that water is wet, and you would never have got past that argument. Nice post though. Very thorough.
55963. Tristan at 12:50 PM on 30 July 2012
       Of Averages and Anomalies - Part 1A. A Primer on how to measure surface temperature change
       How are daily averages for the raw data calculated? Is it as simple as min+max/2?
55964. Tristan at 12:32 PM on 30 July 2012
       2012 SkS Weekly Digest #29
       Thank you very much Tom!
55965. dana1981 at 11:28 AM on 30 July 2012
       2012 SkS Weekly Digest #30
       I presume people are going to be asking us what we think about Watts' new preliminary paper on the accuracy of the surface temp record. After a first read of the paper, I think it has some serious problems. First off I don't think the conclusion ("that reported 1979-2008 U.S. temperature trends are spuriously doubled") is supported by the analysis in the paper. I think the methodology was rather poorly chosen. They compared raw data to fully adjusted data, for example not first correcting for time of day of the observations, so there's no way for us to know how much of any discrepancy they find is due to urban heat effects and how much is due to time of day and other biases that are corrected for in the final product. They found a factor of 2 difference between raw class 1 and class 2 station trends and the final adjusted data set, then they simply assume that whole factor of 2 difference is due to urban heat effects without actually checking to see how much is due to other factors. It's an apples and oranges comparison, so they conclusion is not supported. Their conclusion also doesn't pass the 'sniff test'. Over land, surface and satellite warming trends should be roughly equal, yet they find a factor of 1.6 greater warming trend in the UAH TLT data than in their raw class 1 and 2 surface temp data. So basically if their analysis is right, it means UAH is biased high, which is simply an implausible result. More likely the Watts results are low because they haven't corrected for various other biases like time of day. Note that these are just my first impressions after reading over their paper and it's possible I've missed something, but it appears to me like they have some major problems there.
55966. Rob Honeycutt at 10:09 AM on 30 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       The reason I ended up on this post was because RealOldOne2 was claiming that there is no empirical evidence that humans are causing catastrophic warming. I wanted to start with this post as evidence, first, that humans are causing the dramatic rise in CO2 concentrations. From there I was going to go through radiative forcing and then climate sensitivity. But of course, the whole track, which I think he knows would lead to the answer he doesn't want to hear, ends up derailed on one small point while ignoring all the rest.
55967. Tom Curtis at 09:39 AM on 30 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Rob Honeycutt @46, a typical response for a fake "skeptic". If you recall the story of the blind men and the elephant, the better informed fake "skeptics" are like a blindfolded man, who having felt a trunk insist that elephants are snakes - refusing to either listen to others, or to take of their blindfold and look lest they see any fact that might disturb their opinion. In RealOldOne2's case, he has seized on the C13/C12 ratio and refused to even admit or discuss other relevant evidence. In particular he refuses to consider the prediction with regard to other evidence that would result from accepting his favourite theory. Specifically: a) As previously discussed, if biomass was the source of just half of the atmospheric increase, the total biomass of the planet (including bacteria) must have halved over the last 150 or so years; b) If biomass was the net source of even a significant fraction of the CO2 increase, O2 would have declined by more than the amount required to provide for combustion of known fossil fuel usage, not less; c) If biomass was the net source of a significant fraction of the CO2 increase, it would massively dilute the impact of adding fossil carbon to the system, thereby massively reducing the reduction in the C14/C12 ratio; d) If non-anthropogenic biomass emissions were the source of a significant fraction of the CO2 increase, the 0.997 correlation between anthropogenic emissions and increases in atmospheric concentration would be almost inexplicable; e) If non-anthropogenic biomass emissions were the source of a significant fraction of the CO2 increase, anthropogenic emissions would not have exceeded the increase in mass of atmospheric CO2 by 25% or more in all but nine years since 1850, and every year since 1886; and let's not forget that a biomass origin of the CO2 increase does not explain: f) The extraordinary coincidence in timing between the start of the rapid increases in atmospheric CO2 and the ramp up in anthropogenic emissions. Concentrating on the one line of evidence which is compatible with a biomass origin of the increase in atmospheric CO2 while ignoring the six lines that absolutely rule it out represents a massive cognitive dissonance. It sort of gives a new meaning to the old saw: In the land of the (willfully) blind, the one-eyed (ie, biased) man is king.
55968. Rob Honeycutt at 09:33 AM on 30 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Done.
55969. Rob Honeycutt at 09:17 AM on 30 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Absolutely Tom. I'm impressed with your mastery of the subject matter here, then.
55970. Tom Curtis at 09:04 AM on 30 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Rob Honeycutt @48, I was just looking through part of your debate with RealOldOne2, and noticed that you claimed I am a scientist. While flattered by the number of people who have made that assumption, it is not true. By training I am a philosopher, although my studies (both tertiary and private) have branched all over the place. Could I ask you to correct the record on Peter Sinclair's channel.
55971. JohnMashey at 06:30 AM on 30 July 2012
       Mann Fights Back Against Denialist Abuse
       Climate litigation is fairly recent. For a domain with some useful parallels, study of tobacco litigation can be quite instructive, especially given the wonderful tobacco archives. My favorite book on this, highly recommended, is Robert Proctor's Golden Holocaust: Origins of the Cigarette Catastrophe and the Case for Abolition, see reviews.
55972. JohnMashey at 06:18 AM on 30 July 2012
       Peter Hadfield takes on the MWP
       Daniel: See Ruddiman. But also, go to Real Climate and search for Ruddiman, as there are a few guest posts and commentaries. All this is a dandy example of real science in action, as hypotheses are proposed, challenged, modified, are disproved or (in this case) gain interest and evidence. I'd summarize all this as: 1) Bill has proposed that the CO2 and CH4 behaviors of this interglacial have departed fairly far from those seen in past interglacials, synchronized with the start of agriculture (CO2) and rice (+cows, etc) (CH4). Some of the arguments get complex in analyzing and properly aligning interglacials. Also, there has been a long set of arguments about land-use, i.e., during different eras, how much land had to be cleared per capita? Evidence is accumulating that early farmers needed more land, increasing their CO2 impact. If so, the numbers work pretty well. 2) Bill has proposed that some of the big CO2 jiggles over last 2,000 years came from human plagues, with the 1600AD even being the most obvious. See abstract of the 2008 paper by Nevele, Bird. ' Published reconstructions of Pre-Columbian demography indicate that during European conquest, pandemics killed ~90% of the indigenous American population (~60 million), estimated to represent ~20% of the 16th century global population. Our predictive calculations suggest that fire reduction in the tropical Americas is associated with massive forest regeneration on ~5 x 105 km2 of land and sequestration of 5-10 Gt C into the terrestrial biosphere, which can account for 13- 50% of the ~2% global reduction in atmospheric CO2 levels and the 0.1‰ increase in δ13C of atmospheric CO2 from 1500 to 1700 CE recorded in Antarctic ice cores and tropical sponges. New archeological discoveries revealing extensive networks of geoglyphs and urban polities in Pre-Columbian Amazonia suggest that our estimates of reforestation, and consequent effects on atmospheric CO2, may be conservative.' Or see the News release from Stanfrod. (Basically, in last few decades, researchers have found evidence of a much larger pre-Columbus population, most of whom died, and most were in areas that could regenerate especially large biomass, i.e., like Central America, Brazil.) See also the August 2011 issue of THe Holocene, whose abstracts you can read, including newer one by Nevle, Bird, Ruddiman, Dull. All this is highly interdisciplinary, combining multiple lines of evidence, with researchers and references spread all over the place, like Chinese archaelogists studying the spread of rice farming. Of course, the anti-science crowd, if they understand this, will utterly hate Bill's conclusions, even more than the hockey stick, perhaps, since they mean that humans inadvertently created a thermostat that kept Holocene temperatures within a fairly narrow range ... about to be departed on the high side via the Industrial Revolution.
55973. CBDunkerson at 05:10 AM on 30 July 2012
       Mann Fights Back Against Denialist Abuse
       Andrew, while admissibility is always determined by the judge, my understanding is that the 'Daubert standard' which applies in most US jurisdictions requires that scientific testimony be demonstrably 'valid' through factors such as having gone through peer-reviewed publication, being generally accepted by scientists in the field, having known uncertainty bounds, et cetera. Nearly all of the objections raised by 'skeptics' fail on every requirement. The example you raise would have been decades ago and thus was probably under a rather slapdash congressional standard that allowed just about anything or the older Frye standard, which was similar to Daubert, but less strict. Indeed, I believe the Daubert Supreme Court case was about Bendectin and thus your example is part of the very reason the rules changed. Also note that once a Daubert ruling has been made it is usually followed by other courts in subsequent cases... and there has already been some litigation on climate change. Those cases included several attempts to bar testimony by climate scientists (e.g. James Hansen in Green Mountain Chrysler Plymouth Dodge Jeep v. Crombie). In every case I'm aware of these attempts have failed... mainstream climate science has been upheld as passing Daubert. However, I haven't been able to find any attempts to bring in climate change 'skepticism' in any of those trials. My best guess is that this is because the parties involved were corporations (rather than 'true believers') who knew that such nonsense would fail a Daubert challenge and didn't want to get the judge annoyed at them by trying.
55974. Rob Honeycutt at 04:28 AM on 30 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       BTW... Some folks here I believe have encountered this person before. He goes by the ID of RealOldOne2.
55975. Rob Honeycutt at 04:26 AM on 30 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       I'm trying to get him to come over here to comment but he's a particularly rude person and I'm not sure he could last very long under the commenting policies here. We'll see.
55976. Rob Honeycutt at 04:25 AM on 30 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Okay gang... Here is the guy's response to Tom's comments. "1st, I see that Mr.Curtis confirmed my point that lower C13/C12 ratio is NOT unique to burning FFs.("just as the combustion, DECAY, or RESPIRATION of (or by) biomass will add more C12 than C13 to the atmosphere" So he tacitly agrees that the CAGW "unique FF fingerprint" meme is false. He argues that the biosphere cannot be the source of the increased CO2 in the atmos b/c "PHOTOSYSTHESIS WILL TAKE OUT MORE C12 THAN C13 (his bold) by exactly the same amount per tonne of biomass generated"" "While that is true, Curtis's argument fails in his next statement:"Given that the total amount of biomass in the world is stable...". That is a false assumption, similar to the false CAGW assumption that climate is stable except for human interference. Curtis erroneously concludes that 'pseudo-critics' have no coherently worked out counter proposal that could attribute C13/C12 ratio changes to natural changes. This is manifestly false, as I have pointed out to you previously." "I imagine your confirmation bias &/or cognitive dissonance reflex reactions probably wiped them from your memory, but I'll repeat them since it appears yubedude & others are following our exchanges. bit ly/OyWzLj & bit ly/PuDQl Perfectly plausible physical mechanisms to show that natural sources can be significant contributors to the increases in atmos CO2."
55977. Andrew Skolnick at 04:18 AM on 30 July 2012
       Mann Fights Back Against Denialist Abuse
       I agree with Brandon that "it is inexcusable to compare anyone to a child molester." It's even more inexcusable when the accuser is someone whose teaching career ended after he was arrested and stood trial for sending dozens of obscene messages to a 16-y-o girl, as reported in Brendan Demille's recent HuffPost article, "Affidavits in Michael Mann Libel Suit Reveal Astonishing Facts About Tim Ball Associate John O'Sullivan." http://www.huffingtonpost.com/brendan-demelle/affidavits-in-michael-man_b_1711581.html
55978. Andrew Skolnick at 04:05 AM on 30 July 2012
       Mann Fights Back Against Denialist Abuse
       I wish what CBDunkerson opined would be a slam-dunkerson fact. Rules regarding the admission of scientific evidence are not so reassuring -- in the United States it is left up to the trial judge to decide what is credible and admissible scientific evidence. (I have to wonder whether judges would allow their legal decisions and competence to be officially judged by a panel of appointed climatologists!) Many judges in the U.S. recognize the inadequacy of the court system for decidng matters of scientific debate. Yet, they are often compelled to reach a decision of fact, based on the persuasive powers of hired-gun scientific witnesses. Clearly, courts are not the place to weigh scientific evidence. Rules of evidence in law courts differ greatly from rules of evidence in the court of science. The first major investigative news article of my career was about the science fraud Dr. William McBride. McBride was the Australian physician made famous by being the first to report limb malformations occurring in babies born to women taking Thalidomide. That brought him fame and fortune, which he used to set up a foundation and go around the world testifying in civil suits against all kinds of drugs -- including drugs like Bendectin that are NOT linked to any increase in birth defects risk. In fact, the removal of this anti-nausea drug due to the cost of fighting almost 2000 bogus law suits enabled by the dubious testimony of "experts" like McBride, resulted in many birth defects caused by uncontrolled maternal nausea during pregnancy! I wrote about this medical and legal travesty in the Journal of the American Medical Association in 1990 ("Key Witness Against Morning Sickness Drug Faces Scientific Fraud Charges" http://jama.jamanetwork.com/article.aspx?articleid=380996). I reported how McBride was facing 15 charges of scientific fraud for publishing made-up data -- some of which he hurriedly made up to include in testimony in a U.S. court. McBride was found guilty 3 years later and struck off the medical registry. What shocked me the most was not his fraud, but that the U.S. Justice Department was not interested in pursuing perjury charges against him despite the compelling evidence he had knowingly provided false testimony and made up data in at least one U.S.court case. There appears to be little or no risk for scientists willing to lie under oath about scientific fact or opinion -- at least not in the United States.
55979. Daniel J. Andrews at 03:21 AM on 30 July 2012
       Peter Hadfield takes on the MWP
       Oops. I can check Bill Ruddiman's sources on that last item.
55980. Daniel J. Andrews at 03:19 AM on 30 July 2012
       Peter Hadfield takes on the MWP
       One of the "frustrating" things about this site is that it highlights how quickly my knowledge falls out of date despite my efforts to stay semi-current. Sigh. I can see why denialists harp on a 14 year old hockey stick--it is a lot of work trying to stay current. So once again, thank you to SS and Peter. Time to hit the journals again. Any chance you can do a post or two on some of those ideas highlighted by John in the comments? Intriguing ideas.
55981. JohnMashey at 03:13 AM on 30 July 2012
       Mann Fights Back Against Denialist Abuse
       re: #31 Yes. #27 ended with suggestions to get people to form opinions. I've interacted with Cozen O'Connor before, studied Roger's book and then had a 2-hour breakfast with him last year. Hence, from fairly direct experience, I heartily concur with Andrew's opinions in #31. However, the blogosphere has a lot of Dunning-Kruger-afflictees who have strong opinions on these affairs, as usual without knowing anything.
55982. Andrew Skolnick at 02:47 AM on 30 July 2012
       Mann Fights Back Against Denialist Abuse
       Roger McConchie and John B. Williams have a few things in common. For one, McConchie is at the very top of libel law practice in Canada and Williams is at the top here in the United States. Neither one of them would likely "bluff" in PUBLIC. When a good lawyer bluffs, it's done privately. You don't rise to the top of your legal field by inviting a major news organization to humiliate you by calling your bluff and showing everyone you've got nothing but an empty hand. When a lawyer of Mr. Williams stature releases a public statement about an threatened law suit, he's NOT bluffing. If he did, he would not be at the top of libel law practice in the U.S. for long. Mr. McConchie was NOT bluffing when he demanded a retraction and apology from Tim Ball. When Mr. Williams told the press that he's not bluffing, only a fool would doubt him.
55983. Andrew Skolnick at 02:31 AM on 30 July 2012
       Mann Fights Back Against Denialist Abuse
       BTW, the question as to who is a public figure as pertaining to libel law is not always clear. Generally speaking, all elected officials and people running for public office are. Movie stars and other celebrities usually are (with certain possible restrictions involving invasion of privacy ie. reporting medications and health records, etc.) And parties involved in any "news event," such as crime victims and criminal suspects. They are at least temporarily "public figures." (A person who served time for robbing a candy store 30 years ago when he was 21 years old is NOT a public figure based on that long-ago event.) In addition, people who "thrust themselves into the public limelight" -- those who willingly become a public figure by participating in matters of public concern are public figures. So certainly a scientist like Prof. Mann, who is involved in such a vitally important public debate, would be considered a public figure by any US court judge. To win a suit against his defamers, he would need to prove they knowingly lied or acted with reckless disregard as to the falseness of their accusation that Dr. Mann had committed fraud when he published his "hockey-stick deceptions."
55984. Pete Dunkelberg at 02:27 AM on 30 July 2012
       Peter Hadfield takes on the MWP
       Thanks, Lanfear.
55985. Andrew Skolnick at 02:01 AM on 30 July 2012
       Mann Fights Back Against Denialist Abuse
       Anyone who knows anything about U.S. libel law would know to be skeptical about Sceptical Wombat's statement that being a "public figure," Prof. Mann would have to prove Steyn and the National Review "knew" what they published about him was false. Not true. In 1964, the US Supreme Court decision in NY Times vs. Sullivan established the current law regarding "public figures." To win a libel suit in US courts, a public figure like Prof. Mann is required to prove the defendant published or broadcast the defamatory speech with "malice" -- which means either knowing that the speech was false or acting with "reckless disregard as to whether the speech was true or false." That's obviously a MUCH lower bar to clear than proving the party deliberately lied -- which usually requires "smoking gun" evidence (ie. email between the defendants bragging how they got away with a real big whopper.) Simply showing that the reporter made NO effort to verify the defamatory statement and gave the defamed person no chance to respond, is often enough to allow a public figure to win a libel suit. In this case, Prof. Mann should have no trouble clearing the public figure hurdle.
55986. Tristan at 01:32 AM on 30 July 2012
       Monckton Misrepresents Reality (Part 3)
       Monckton tries his hands at some anti-Muller math.
55987. Lanfear at 01:21 AM on 30 July 2012
       Peter Hadfield takes on the MWP
       Pete@5 You mean something like this? There seems to be one separately for politicians too (US only).
55988. Tristan at 01:08 AM on 30 July 2012
       Medieval Warm Period was warmer
       Will we see a discussion of Ljungqvist, F.C., Krusic, P.J., Brattstrom, G. and Sundqvist, H.S. 2012. Northern Hemisphere temperature patterns in the last 12 centuries. Climate of the Past 8: 227-249. At some point?
55989. Pete Dunkelberg at 00:48 AM on 30 July 2012
       Peter Hadfield takes on the MWP
       This video shows so many deniers it makes me wonder if there is a list of significant public deniers anywhere. How many are there, between 20 and 30?
55990. shoyemore at 00:29 AM on 30 July 2012
       Peter Hadfield takes on the MWP
       Another small "nit" that might have been mentioned, but possibly was too complicated to explain If the earth heated up very quickly in the MWP (not due to CO2) then that says something about the earth's climate sensitivity to the forcing agent, whatever it was. If it was the sun, it suggests that as the sun becomes more active, coupled with the anthropogenic CO2, then the earth's climate will heat up even faster than it is doing now. Not a propsect Lord Monckton and his minions want to deal with, it seems. PS Well played, Peter Hadfield. Thank God someone has the patience to hunt down those "adjusted" charts. I know I would not.
55991. mercpl at 23:07 PM on 29 July 2012
       Peter Hadfield takes on the MWP
       Bill, With reference to your comment about Muller's op-Ed piece, i wonder if that is the major announcement that has caused the WUWT site to as suspended publication. Maybe Anthony Watts has changed his mind too.
55992. Rob Painting at 20:33 PM on 29 July 2012
       2012 SkS Weekly Digest #29
       Tom, see: Major influence of tropical volcanic eruptions on the stratospheric aerosol layer during the last decade - Vernier (2011)
55993. Tom Curtis at 19:36 PM on 29 July 2012
       2012 SkS Weekly Digest #29
       Tristan @9, GHG are not the anthropogenic forcings. Over time, aerosols have increased albedo, and changed the properties of clouds which have also affected the global energy balance. Likewise, changes in land use (LUC) have changed the surface albedo, also affecting the energy balance. Importantly, these additional effects are cooling effects and combined, are quite large compared to the GHG forcing, currently almost halving the positive forcing from GHG. They following is Figure 1 C from Skeie et al, 2011 - a recent attempt to quantify all anthropogenic forcings: Please note the dashed red line, ie, the net effect of anthropogenic forcings. There are two primary natural forcings, solar and volcanic aerosol emissions. These are shown in the following graph by the IPCC as brown (solar) and dark blue (volcanic): Unfortunately the figure does not carry through to 2010. In the intervening period, however, solar irradiance has declined. I am uncertain about the volcanic aerosol forcing, but it cannot be very large due to the absence of recent large volcanoes near the equator.
55994. Tom Curtis at 18:59 PM on 29 July 2012
       Of Averages and Anomalies - Part 1A. A Primer on how to measure surface temperature change
       heb0 @13, actual temperature series from weather stations that are close together geographically are highly correlated (see fig 3 from Hansen and Lebedeff in the main article). They may, however, differ greatly in the absolute value of their measurements. Thus, for example, if you have two weather stations close together, but one on the top of a mountain while the other is near the base, their temperature anomalies from day to day are likely to be very similar, even though the difference in altitude will cause one to consistently record temperatures significantly lower than the other. Indeed, the weather station on top of the mountain may consistently record temperatures much lower relative to the one at the base, than the day to day differences in temperature at both stations. The strong regional correlation, and hence near approximation of the anomalies of nearby stations, is, I believe what makes the average of the anomalies superior to the anomaly of the averages. It is certainly what is violated in Greg Houses example @12. It would be interesting if you were to check this by imposing strong regional correlation on your model, instead of allowing them, as you currently do, to fluctuate at random with respect to each other.
55995. Doug Hutcheson at 18:58 PM on 29 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Thanks for this post, Tom. I have linked to it in an amusing debate over at Aussies Living Simply (ALS) (my pseudonym there is 'owlbrudder').
55996. Tristan at 18:47 PM on 29 July 2012
       2012 SkS Weekly Digest #29
       A humble request for what I'd find to be a useful page, having spent a lot of time in the skeptosphere. What is the observed contribution of GHGs to warming from the 1850-1890 (which I dub 'then') period till now? The page would need The size of the anomaly due to TSI for then vs now The size of the anomaly due to AOD for then vs now And an explanation of: GHG anomaly = total anomaly - AOD anomaly - TSI anomaly And why we're fairly sure that those 3 factors make up almost all the observable temperature differences. It would really put the low sensitivity claims to the sword. It'd make it pretty hard to argue for an ECS of 1.2C if we had a clear link explaining that we've already experienced around that much warming due to GHGs.
55997. JohnMashey at 17:44 PM on 29 July 2012
       Peter Hadfield takes on the MWP
       Great video, only one real not and one minor one. 1) Wegman Report. Everybody agreed non-centered PCA was not right, but it was also shown (by Wahl&Amman) that it made no significant difference. There was no new good statistics in the Wegman Report, which reran McIntyre's code, and the only way to get his effects was: a) Use unrealistically high persistence parameters b) Do a 1:100 cherry-pick of the most positive hockey-stick looking charts. See Deep Climate's Replication and due diligence, Wegman style. After (falsely) criticizing Mann for never providing code, Wegman then told untruths to Rep Henry Waxman, promising to release the code (never done), as soon as it got through US Navy release procedures. The Navy had nothing to do with it. Anyway, the Wegman Report shows little evidence of statistical expertise. 2) As a minor nit, this shows CO2 over last 2000 years, from Law Dome. While I would never ascribe all the temperature jiggles to CO2, one might notice where the low and high points are compared to the temperature reconstructions. In Plows, Plagues and Petroleum (and earlier papers), Bill Ruddiman proposed several hypotheses: a) Even pre-industrial era, human land-use changes (cutting down trees, rice farming~methane, etc) kept Earth warmer than one would expect from past interglacials. I.e., without humans, CO2 in 1000AD would have been lower. b) CO2 jiggles over last 2000 years have at least in part been caused by human plagues, which caused reforestration, which drew down CO2. The biggest, sharpest dip (1535-1600) seems to have been caused by the single biggest plague in history, the 50M person die-off in the Americas, post-Columbus. c) While controversial ~2005, more scientists have gotten involved and evidence has been piling up in support of these hypotheses. In effect, it means that since agriculture started, humans mostly nullified the start of the long, slow descent to ~180ppm CO2 one would normally expect. Hence, we actually did contribute to the MWP, perhaps and the LIA. The latter is ironic: Europeans gave America smallpox, etc, but got the LIA in return.
55998. heb0 at 16:33 PM on 29 July 2012
       Of Averages and Anomalies - Part 1A. A Primer on how to measure surface temperature change
       First, thanks for the post. I've found it immensely helpful. I read it when it was first posted and have now found my way back to it to refresh myself. I have one problem, however. I understand the advantages of the 'average of anomalies' method for problems with variations in average temperature between locations, but I'm missing how it is less sensitive to dropped stations than is finding the anomaly of the averages. To test this, I generate an array of 500 average temperatures that vary between 15 and 30 degC, then generate an array of 500 temperatures that are allowed to vary randomly from each station average (within certain bounds). I then create arrays with certain "stations" removed (I've played around with the number, but I started out dropping 20 stations), and then compare all the values: real, average of anomalies, and anomaly of averages. It turns out that neither method is consistently closer to the real value and, in fact, upon 500 iterations of the code, it seems each is the better estimate about 50% of the time. Is this actually the case, or is there some physical explanation for the advantage of finding the 'average of anomalies' when accounting for dropped stations that wouldn't be reflected in my randomly-generated values?
55999. bill4344 at 16:12 PM on 29 July 2012
       Peter Hadfield takes on the MWP
       Another great vid from Potholer. So, who's been fiddling with the charts, then? Between this and Muller's 'call me a Converted Skeptic' NYT OpEd this is turning into quite the memorable day!
56000. jyyh at 15:55 PM on 29 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Hmmph..."12C preference"

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