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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 124701 to 124750:

  1. Berényi Péter at 02:01 AM on 30 January 2010
    The IPCC's 2035 prediction about Himalayan glaciers
    Charlie A at 12:52 PM on 28 January, 2010 "I have found a peer reviewed paper from Geophysical Research Letters that supports the AR4 findings!" The peer reviewed paper in Geophysical Research Letters is this one: GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L22503, doi:10.1029/2008GL035556, 2008 Mass loss on Himalayan glacier endangers water resources Natalie M. Kehrwald, Lonnie G. Thompson, Yao Tandong, Ellen Mosley-Thompson, Ulrich Schotterer, Vasily Alfimov, Ju¨rg Beer, Jost Eikenberg, and Mary E. Davis Received 1 August 2008; revised 24 September 2008; accepted 21 October 2008; published 22 November 2008. http://bprc.osu.edu/Icecore/Kehrwald%20et%20al%202008.pdf It actually contains the phrase "The surface area of glaciers across the TP is projected to decrease from 500,000 km2 measured in 1995 to 100,000 km2 in 2030 [Cruz et al., 2007]" Cruz et al., 2007 is of course IPCC AR4, WG II Report, chapter 10. No problem, AR4 was subject to peer review, even if a slightly redefined version of it. Cruz, R. V., H. Harasawa, M. Lal, S. Wu, Y. Anokhin, B. Punsalmaa, Y. Honda, M. Jafari, C. Li, and N. Huu Ninh (2007) Asia, in Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by M. L. Parry et al., pp. 469–506, Cambridge Univ. Press, Cambridge, U. K. http://www.ipcc.ch/pdf/assessment-report/ar4/wg2/ar4-wg2-chapter10.pdf The GRL quote is based on an IPCC/AR4 Figure 10.4 caption (Hotspots of key future climate impacts and vulnerabilities in Asia), which reads "Tibetan Plateau glaciers of 4 km in length are projected to disappear with 3°C temperature rise and no change in precipitation. If current warming rates are maintained, glaciers located over Tibetan Plateau are likely to shrink at very rapid rates from 500,000 km2 in 1995 to 100,000 km2 by the 2030s. [10.4.4.3,10.6.2]" The Kehrwald at al. quote is an abridged version of it. They omitted the generous 3°C temperature thing along with the restriction "no change in precipitation", and the tiny letter "s" after "2030" (it may be the source of the IPCC:2035 - NASA:2030 transition). BTW, the "glaciers of 4 km in length" is also omitted, a pity, for it is absolutely mysterious. Otherwise it is correct. To tell the truth, I would like to have a word or two with the anon referees of GRL who let this crap through. But IPCC GR4 Himalayan glacier claim got supported by a peer reviewed paper, even if it was done in retrospect, based on the very report to be supported. New Age science is supposed to work this way, isn't it?
  2. The upcoming ice age has been postponed indefinitely
    I think there's some confusion there between (a) a huge explosive event at, say, Yellowstone, which could potentially inject a lot of aerosols into the stratosphere, and (b) a broad-scale, multi-century flood basalt event like the Siberian traps or Deccan traps, which would outgas a lot of CO2. Yes they're both catastrophic volcanism but the climate impacts are quite different.
  3. Berényi Péter at 01:02 AM on 30 January 2010
    Peer reviewed impacts of global warming
    canbanjo at 10:36 AM on 28 January, 2010 "what hope does africa have?" None. Solar power is hopeless until solar panel prices drop below that of leaves, a goal achievable only by self replicating systems. It requires brand new technology not developed yet.
  4. Lessons from the Monckton/Plimer debate
    MarkJ (Post #1), Here's one geologist's perspective (mine!). The argument can be broken down like this: 1) There is strong geologic evidence that surface temperatures have varied significantly in the Earth's past, both up and down. One of the indicators of this is the presence or absence of polar ice caps. (We can see evidence of glaciers in the sedimentary rock record, so we know when ice caps have been here in the past). Therefore, we know that surface temperature has changed a lot, and is sensitive to something... But what?? 2) Evidence shows that a number of factors can drive changes in temperature, including variability in Earth's orbit, variations in solar emissions, changes in atmospheric composition, changes in albedo, etc.; HOWEVER!.. The geologic record shows that elevated CO2 consistently shows up "at the scene of the crime" when the Earth has experienced past episodes of warming (For an informative, entertaining summary of this, listen to geologist Richard Alley's lecture from the recent AGU meeting. It will take an hour, and may be a bit technical, but I hope you'll find it worthwhile. http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml 3) But even if periods of high temperatures are always associated with high CO2, how do we know which caused which? This one's harder to answer in just a few sentences, so you'll have to do some homework, but you can think of increasing atmospheric CO2 as being like adding more blankets on to your bed on a cold night. The more blankets you add, the warmer the bottom blanket will be, and the cooler the top blanket will be. That's why adding more CO2 keeps causing more warming, even though the absorption bands are saturated. 4) There's one final argument although it's a bit weaker: The CO2 model fits most of the evidence, and right now we have no other way to explain these past temperature changes other than CO2. The same argument holds for late 20th Century warming! In contrast, Lord Monckton claims that the atmosphere is self-regulating, and that there are negative feedbacks that prevent the atmosphere from getting warmer when you add CO2. Monckton is just smart enough to seem like he knows what he's talking about, but actual climate scientists see many flaws in his arguments. Monckton and Plimer may mean well, and might even believe what they say (?), but in the end science is not on their side. A Little Knowledge + A Lot of Bias = A Dangerous Thing
  5. The upcoming ice age has been postponed indefinitely
    Actually, Chris, they reckon something similar happened around 4,000 years ago-a slowing of the Gulf Stream caused an extreme cool period in Europe whilst causing a major drought to Egypt & the Middle East-the drought which brought down the Egyptian Old Kingdom.
  6. Lessons from the Monckton/Plimer debate
    fydijkstra: "...and Monckton says that the sensitivity of the climate for greenhouse gasses is much smaller than IPCC claims." The point is, though, that the sensitivity is determined by the feedback effects resulting from the temperature change due to a particular forcing irrespective of the forcing's cause, whether it be changes in the solar irradiance, the shape of the Earth's orbit or the composition of the atmosphere.
  7. The upcoming ice age has been postponed indefinitely
    Ubique. From everything I've read on Yellowstone, if it erupts it won't cause warming-it will cause extreme, localized cooling (not unlike a nuclear winter). If it blows, you can pretty much say goodbye to the bulk of the human & animal population of North America for the next few centuries at least. However, just like the possibility of rogue asteroids, it would be extremely foolish to do nothing to prevent man-made global warming just because of the 1:1,000,000 chance of a super-volcano explosion.
  8. Peer reviewed impacts of global warming
    The Sahara was more fertile before about 4K years ago when the temperature was hotter. Is it possible that it will become so again when global warming kicks in?
  9. Berényi Péter at 23:03 PM on 29 January 2010
    Guest post in Guardian on microsite influences
    Could anyone provide a pointer to the literature of "data homogenization" as a statistical procedure? I mean the kind of study that would discuss it on its own right, independent of Climate Science. I looked hard, but could come up with nothing. There is something called data homogenization used in data warehousing, but in the absence of metadata it relies heavily on AI technologies like pattern recognition. It is not meant to be used to produce "objective" datasets, just hints. In other words it is woodoo magic, not a tool for science. BTW, Menne at al 2010 do depend on data homogenization. http://www1.ncdc.noaa.gov/pub/data/ushcn/v2/monthly/menne-etal2010.pdf
  10. Arkadiusz Semczyszak at 22:55 PM on 29 January 2010
    Lessons from the Monckton/Plimer debate
    5. 4. Exxon - he depends only on the same subsidies for CCS as well as in Europe. If current warming would, for instance, such as the Older Peron, the money is better spent on protection against transgression of the sea.
  11. Lessons from the Monckton/Plimer debate
    fydijkstra, either climate *is* sensitive to forcing or it isn't-you can't have an each way bet, as Monctkon chooses to have. The properties of the various greenhouse gases has been established over more than a century-especially its ability to capture Long-wave infrared radiation (heat). To try & claim otherwise is to refute more than a century of chemistry & physics. It comes down to this simple question-average global temperatures have risen by around +0.5 degrees over the last 30 years, yet solar activity has declined by around an average of 0.3 watts/meter squared per decade over that similar time period. So where is the extra heat coming from? Until so-called skeptics can produce a valid, alternative theory for the warming trend, then they really lack any credibility!
  12. Arkadiusz Semczyszak at 22:41 PM on 29 January 2010
    Lessons from the Monckton/Plimer debate
    3. A propos CHYŁEK - is not a skeptic, at most: "semi" skeptic. Skeptics believe, that the former: first followed the rise in temperature, then CO2 (soil bacteria and ocean heterotrophic bacteria - they are to blame), but CO2 - never had a significant effect on temperature. Water vapor, feedback is always neutralize majority of RF CO2.
  13. The upcoming ice age has been postponed indefinitely
    John, 'The burp from one volcanic eruption would overpower all the CO2 humans have ever emitted'. The numbers say otherwise as does the CO2 record which shows not a blip during the 20th Century's largest volcanic eruptions. Do you think he might be referring to the eruption of a super volcano – such as the one under Yellowstone National Park – rather than one like Mt St Helens in British Columbia in Canada? I lived in Canada down wind of that one when it blew and it certainly had an effect upon the climate locally. When Yellowstone blows (overdue they tell us) the impact will be global.
  14. Lessons from the Monckton/Plimer debate
    One afterthought: Monckton does not say that the climate has a low sensitivity. He only rejects the hight sensitivity for CO2. Solar magnetism, cosmic rays, and orbital forces, that may have caused past climate changes may have much more influence than IPCC admits.
  15. The upcoming ice age has been postponed indefinitely
    re #35 The temperature minimum at the Maunder minimum has been examined in some detail. The solar irradiance contribution from suppressed solar activity is considered to have been as much as 0.2 oC globally averaged compared to the mid-20th century level (top article and your own analysis). The Maunder Minimum (MM) and the Little Ice Age (LIA)was also a period of considerable volcanic activity, and this is expected to suppress the temperature (globally-averaged) by around another 0.1 oC. This can pretty much cover the full extent of the MM/LIA cooling when considering a global (or even N. hemisphere average). For example, the most variable paleoreconstruction covering the last ~ 2000 years [*] indicates that the "baseline" (N hemisphere-averaged) temperature was around -0.4 oC (compared to mid-20th century) for several hundred years before the Medieval warm Period (MWP). NH temp rose to ~ 0 oC (relative to mid-20th century) at the height of the MWP around 1000 AD, and dropped to around -0.7 oC at the depths of the MM/LIA (see Figure 2 of Moberg et al [*]): [****] A. Moberg et al. (2005) Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data Nature 433, 613-617 coast.gkss.de/staff/storch/pdf/moberg.nature.0502.pdf Since global (hemispherically-averaged temperature changes are concentrated over land and often "focussed" in the high N. latitudes, a temperature drop of -0.3oC, can equate to a much larger temperature drop (-1 oC or more) in Western Europe where the LIA is documented. Likewise there is evidence that the Gulf Stream intensity was reduced during the period of the LIA (perhaps in response to reduced solar forcing) [**], and this is likely to have reinforced a gradient of cooling in the N. hemisphere with the Western Europe fringes getting the largest cooling whack...thus those pretty pictures of revellers on the frozen Thames, and hunters in the snow in Holland by Breugel... [**] Lund DC (2006) Gulf Stream density structure and transport during the past millennium Nature 444, 601-604 http://www.nature.com/nature/journal/v444/n7119/abs/nature05277.html
  16. Lessons from the Monckton/Plimer debate
    Monckton's and Plimer's opinions are not contradictory. Plimer argues that the climate has changed very often in the past, due to other reasons than greenhouse gasses, and Monckton says that the sensitivity of the climate for greenhouse gasses is much smaller than IPCC claims. These two arguments are complementary.
  17. Arkadiusz Semczyszak at 21:49 PM on 29 January 2010
    Lessons from the Monckton/Plimer debate
    1. During volcanic eruptions (very large) amount of CO2 accumulated in the atmosphere falls sharply ("Sinks for anthropogenic carbon", J.L. Sarmiento and Gruber N.; 2002, page 32, Fig. 3.). Accumulated amount of CO2 in the atmosphere is highly dependent on temperature changes -http://www.jennifermarohasy.com/blog/archives/Jan%20Pompe_co2%20and%20temp2.gif. Particularly NH temperature. So they can only respond quickly to natural sources of emissions - soil bacteria (I recall the experiment Biosphere 2). Volcanic aerosol = less SI for plants = less photosynthesis = fall NPP = more CO2 in the atmosphere ... 2. Former historic temperature changes were much more violent, than the current (f. e.: "Abrupt tropical climate change: Past and present", L. G. Thompson; 2006 -http://www.pnas.org/content/103/28/10536/F4.large.jpg).
  18. Lessons from the Monckton/Plimer debate
    To MattJ (6) Succinctly put. Scientists need to budget time and resources now to learn PR and new communication skills. Or perhaps use their endless riches in funding (not) to hire people already with these skills, like Exxon did.
  19. The hockey stick divergence problem
    MattJ, as far as i know the final word on the divergence problem has not been said. Anyone is open to the possibility that the same problem showed up in the past but at the moment there's no evidence of it given the overall agreement of many different proxies.
  20. There's no empirical evidence
    samantha, it's a more than two years old story and has been refuted so many times that there should be no need to pull it back. Give a quick look here and at the links provided.
  21. The hockey stick divergence problem
    A large portion of the article, and many of the comments are devoted to defending the thesis that the 'divergence' is man-made, and that there is no attempted cover-up. Well and good. I believe this thesis is established. But what I would like to see and do not see, is proof that similar divergences could not happen in the past. Simply proving that today's divergence is man-made does not prove this, though the suggestion is rather strong. At some point, the skeptics will think to ask this, once they figure out there are not making much headway with their false accusations of cover-ups. So it is important to do. The hard part, of course, is figuring out what kind and level of proof is even possible. I don't know trees well enough to come up with helpful suggestions there.
  22. Lessons from the Monckton/Plimer debate
    Your last sentence sums it up very well: "Two skeptic arguments can contradict each other, even on the same debating stage, so long as the common enemy of man-made global warming is refuted." This illustrates the difference between the scientist, the politician, and the general public. The scientist has put many years of educational effort in to learning the importance of logical reasoning at many levels, the general public has never done this. So of course, they are highly susceptible to Monckton's style of crass manipulation, they even welcome it. But here is the real problem: scientists well aware of the threat of AGW have never taken a scientific approach to understanding how the general public forms opinions, and so is outmanouvered by professional deceivers like Monckton every time. We are running out of time to close this PR gap. We may have run out already.
  23. Lessons from the Monckton/Plimer debate
    What the USGS says about volcanoes and gases Comparison of CO2 emissions from volcanoes vs. human activities. Scientists have calculated that volcanoes emit between about 130-230 million tonnes (145-255 million tons) of CO2 into the atmosphere every year (Gerlach, 1991). This estimate includes both subaerial and submarine volcanoes, about in equal amounts. Emissions of CO2 by human activities, including fossil fuel burning, cement production, and gas flaring, amount to about 27 billion tonnes per year (30 billion tons) [ ( Marland, et al., 2006) - The reference gives the amount of released carbon (C), rather than CO2, through 2003.]. Human activities release more than 130 times the amount of CO2 emitted by volcanoes--the equivalent of more than 8,000 additional volcanoes like Kilauea (Kilauea emits about 3.3 million tonnes/year)! (Gerlach et. al., 2002) http://volcanoes.usgs.gov/hazards/gas/index.php
  24. Lessons from the Monckton/Plimer debate
    John, I'm sure you're aware of it, but Plimer has been ambushed, about his claims about volcanoes and CO2 and shown to be dishonest, but he prevaricated and tried very hard to distract and change the subject. Plimer has no shame. Partial [edited] transcipt GEORGE MONBIOT: .... Take, for example, his claim that human beings produce more carbon dioxide than volcanoes. Now, the US geological survey shows that human beings - sorry, he suggests that volcanoes produce more carbon dioxide than human beings. The US geological survey shows that human beings produce 130 times more carbon dioxide than volcanoes. And yet again and again, however many times it is pointed out to him, Ian keeps reporting this straightforward fraud, this fabrication that volcanoes produce more CO2. ... IAN PLIMER: Well I'm very heartened that a journalist is correcting me on my geology. Now Mr Monbiot wrote to me when I asked him some questions of science and said he was not qualified to answer these questions of science. So he's a journalist and he's asking me a scientific question. He has not read this book ... .... IAN PLIMER: Well, let me make two points on this. On the chapter called Earth I talk about two volcanoes. One are the terrestrial volcanoes, which is the USGS reports on emissions of carbon dioxide, but more than 85 per cent of the world's volcanoes we do not measure, we do not see, these are submarine volcanoes that release carbon dioxide and we deduce from the chemistry of the rocks how much carbon dioxide is released. TONY JONES: Can I ask you a question about that, if you don't mind? Because one British journalist whom you quoted those exact figures to went back to the US geological survey after you told him about this 85 per cent figure, and asked he them to confirm their claim that actually 130 times the amount of CO2 is produced by man than volcanoes. The volcanologist Dr Terrance Gerlach confirmed that figure and said furthermore that in their counting they count the undersea volcanoes. So your response to that. IAN PLIMER: My response is that there are 220,000 undersea volcanoes that we know about. There's 64,000 kilometres of undersea volcanoes which we do ... GEORGE MONBIOT: Which they have counted. IAN PLIMER: It is the height of bad manners to interrupt. Please restrain yourself. And we have 64,000 kilometres of volcanoes in submarine environments with massive super volcanoes there. We do not measure them. And the figures that I have used are deduced from the chemistry of rocks which erupt on the sea floor. TONY JONES: OK. Now, that's that point dealt with. George Monbiot, a quick response to that and then we'll move on to other questions. GEORGE MONBIOT: Yeah, sure. I mean, it's, again, straightforward fabrication. Ian produces no new evidence to suggest that the USGS figures are wrong. He keeps citing this statement that they don't include submarine volcanoes. It's been pointed out to him many, many times that the USGS figures do include submarine volcanoes. And actually, it's the height of bad manners Professor Plimer to lie on national television about something that you know to be plain wrong. You get the flavour. The transcript is at: http://www.abc.net.au/lateline/content/2009/s2772906.htm
  25. Lessons from the Monckton/Plimer debate
    I saw Monckton being interviewed by Ben Cubby on smh.com.au and he was very funny - mostly from making such outrageous claims. I think it's in part intentional. As you say, he knows how to work the crowd. A comment on your statement: "In a sense, this perfectly encapsulates the skeptic movement as a whole. Global warming skepticism isn't about furthering scientific understanding but proving that humans can't be causing global warming." Let's assume you are right and have summarized the "movement". I'm fairly new to your website so feel free to tell me to not bother with these kind of comments I'm about to make.. they aren't meant to be critical.. It seems like you have put a lot of time into creating the site and a lot of the material is specifically aimed at skeptics. So you care about educating "the skeptic movement", which is wonderful. If it's really aimed at that "movement" I think you will be doing your hard work a disservice by putting down the people you want to help. There are a lot of people out there really trying to figure stuff out. But they don't have physics degrees, have never read an undergrad book on radiative physics and have only a very hazy idea of "the scientific method". So pretty much anything can sound authoritative. One way to put people off is to tell them how dumb they are. Much worse - tell them their ethics and motives are flawed. They will go and hang out somewhere they feel more comfortable. And so your hard work will only achieve 20% of its potential.
    Response: I appreciate your comments. I always try to avoid alienating people by characterisation and I didn't quite achieve that goal this time around. I've tweaked the wording of the final paragraph so that it addresses the arguments, not the people.
  26. Lessons from the Monckton/Plimer debate
    Yes, excellent point John. I saw Monckton on the ABC with Ben McNeil. The classic moment was when Monckton turned to Ben and said "of course you are not an expert in climate science". He then waffled on about sensitivity referring to Lindzen with no chance to be contradicted (and in any case the contradiction is too complicated for a lay audience, especially in the time allowed on a current affairs show). Very clever tactic. And I would like to ask Plimer why on Earth he believes that climate change in the past contradicts AGW now. Does he really believe that a rapid change occurring over the last 30-40 years is the result of the same natural causes as the slow geological changes? And if so, why? But I'm sure he wouldn't answer (which is his clever technique).
  27. Lessons from the Monckton/Plimer debate
    Good morning, I was wondering if you could elaborate on how the the 2 skeptic positions of natural variability and low climate sensitivity contradict each other? Seems to me that both arguments say CO2 does not play as nearly a large role in climate as the majority of scientists argue.
    Response: Good evening (here in Brisbane at least). I'll try coming at it from another angle in the hope that it clarifies the science more. As Barry Brook explained today (after Plimer dodged my question), climate doesn't change by magic. It changes because it's forced to change. The forcing that changes climate is changes in the planet's energy balance - when the planet is accumulating heat or losing heat. This energy imbalance is also called radiative forcing.

    So a key question with climate is how sensitive is our climate to radiative forcing? For example, if you doubled atmospheric carbon dioxide which has a radiative forcing of 3.7 W/m2, what is the global change in temperature? The extra heat causes a direct surface warming of around 1.1°C. But then feedbacks come into play. The warming causes more evaporation which puts water vapor into the atmosphere - the greenhouse effect of the extra water vapor has an amplifying effect. Ice melts, lowering the Earth's albedo which causes further warming. There are also potential negative feedbacks - if clouds increase, this raises the Earth's albedo which has a cooling effect. So when you put it all together, does the planet have net positive feedback (which would mean a higher climate sensitivity) or a net negative feedback (lower climate sensitivity).

    We work out climate sensitivity by looking at past climate change. We work out what the forcings were that drove climate, we use proxies to determine how much temperature changed and from this, we calculate climate sensitivity. Often scientists look at periods of great change such as the Last Glacial Maximum where the earth came out of an ice age. And what these analyses find is that our climate has high sensitivity. It has net positive feedback. The great climate changes observed in the past are not possible without high climate sensitivity.

    So when Ian Plimer cites past climate change, he's citing evidence for high climate sensitivity. This is in direct contradiction to Monckton's position that our climate has low sensitivity.
  28. On the reliability of the U.S. Surface Temperature Record
    Leo G, now to relate my explanation to the light bulb analogy: The replacement of the instruments is analogous to replacing the thermometer in the room with the light bulb, when the new thermometer reports slightly cooler temperatures than the previous thermometer did. The resulting cooler measurements have nothing to do with the light bulb. The poor siting of the new instruments was not the cause of the cooling. The poor siting was merely an accidental clue to the discovery that the new instruments were cooler. And why didn't the anomaly computation compensate for this artificial coolness? Because the situation changed. An anomaly computation compensates only for a constant bias. In this case the bias changed with the instrument replacement, but the anomaly continued to be computed off of the same baseline, so of course the anomaly accurately reflected the new bias. Use of anomalies does not correct all kinds of errors. Other adjustments are carefully made to compensate for changes in instrument, instrument type, specific location, and other situations.
  29. On the reliability of the U.S. Surface Temperature Record
    Leo G, the cool bias that Menne found was created by the replacement of one kind of instrument with another, at the same locations. The instruments don't last forever, so they must be replaced, even if by the same kind. When that is done, scientists check the new instrument's measurement against the previous one. Any discrepancies in the measurements of the two instruments must be eliminated by changing all the historic temperatures from the previous instrument, or by changing all the future temperatures from the new instrument. In this particular replacement of one kind of instrument with another kind, one specific difference between the two kinds was not detected during that calibration. So the new instruments were reporting slightly cooler temperatures than the old instruments would have, but nobody knew that. Those slightly cooler measurements started happening only recently, because that's when the instruments were replaced. The shift to cooler measurements was not obviously sudden in the average across all stations, because the instruments were not replaced all at once. As more instruments were replaced one by one, the average temperature consequently became progressively cooler. Someone probably would have noticed the pattern eventually, if they had compared the new type of instrument's measurements against the old type of instrument's measurements across a whole lot of measurements. That comparison eventually did happen, by the fluke of the new instruments being worse sited than the old instruments were. (The new instruments were tethered too close to buildings.) When Menne discovered the worse-sited instruments were slightly cooler than the better sited instruments, he tried to figure out why, by looking for characteristics common to the worse-sited instruments. He found they tended to be the new instruments. So then he did the explicit comparison of new instruments against old that I mentioned in the last sentence of my previous paragraph.
  30. The upcoming ice age has been postponed indefinitely
    What is the expected surface temperature change caused by the change of radiative forcing due to the maunder minimium? If you are saying that the change in radiative forcing is about 0.2 and given a change of 1 leads to a surface temperature change of ~0.6oC then are we looking at an estimated drop in temperature of 0.12oC. How did this ever manifest itself in any noticable change in the climate? It's the difference between 2005s climate and 2010s climate.
  31. The upcoming ice age has been postponed indefinitely
    Finally found the paper I referenced above (#25) "High-resolution Holocene climate record from Maxwell Bay, South Shetland Islands, Antarctica", K.T. Milliken, J.B. Anderson, J.S. Wellner, S.M. Bohaty, and P.L. Manley, GSA Bulletin, November/December 2009; V 121; no. 11/12; p 1711-1725; doi: 10.1130/B26478.1 From the abstract (as I have yet to read through the whole thing for a blog post): "After 2.6 ka, the climate varied slightly, causing only subtle variation in glacier grounding lines. There is no compelling evidence for a Little Ice Age readvance in Maxwell Bay. The current warming and associated glacial response in the northern Antarctic Peninsula appears to be unprecedented in its synchronicity and widespread impact." Not being a glacier expert, it'll take me some time to make heads or tails of this particular paper, but it looks like the authors are trying to determine if the current meltback on the Antarctic Peninsula has antecedents or not. Cool stuff.
  32. There's no empirical evidence
    What are peoples thoughts on Gerlich & Tscheuschner's paper "Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics"? http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v4.pdf A quick rundown can be found here: http://climaterealists.com/index.php?id=4992
  33. On the reliability of the U.S. Surface Temperature Record
    Tom @ 148 - ahhh yes, of course! 19C, thanx. So how does Menne get this bias to cooling? Thought I had figured it out..... Doug @ 149 - hmmm, yes I think I get it now, I was thinking too literally in Temperature, not thinking in energy gain/loss. note to self - temp is just a tool to help show energy changes as weight is for mass on earth! thanx again gents, will hopefully be better next time! PS - John, great site, full of respect and knowledge, you may get me off that lukewarm fence yet!
  34. On the reliability of the U.S. Surface Temperature Record
    It would appear that 'skeptics' believe every station shift or microsite issue leads to a warm bias. this must be why they never, ever report on individual stations that have a cooling bias due to various non-climatic changes. What they do is collect examples of (possible and actual) warm biased stations and generalise from there. What needs to be done, and what has not been done by the skeptics, is the quantitative analysis that would show whether this assumption has merit. That does not prevent conclusions being drawn from anecdotes, unfortunately. In the Watts post on Menne et al we learn that the quantitative analysis is finally going to be done in an upcoming paper, but Even Jones advises further down in the comments that it 'won't do' to simply use the raw data from good stations - that something must be dug out because "more is going on". It will be ironic if they end up 'adjusting' the data, considering the overriding memes at WUWT. I look forward to the quantification of the project undertaken by surfacestations. Though much of the carry on at WUWT is woeful, I maintain that the rating of USHCN by Watts and collaborators is a boon to climatology.
  35. Human CO2 is a tiny % of CO2 emissions
    Lord Monckton is quoted as saying that if every nation were to cut emissions by 30% over the next 10 years, "the warming forestalled would be 0.02 degrees celsius, at a cost of trillions". Is this true?
  36. Guest post in Guardian on microsite influences
    Yes, I did, but it's nice to have the pointer to the ncdc page ... is Menne 2010 the first paper to compare data from the new network with the old, historical weather station network? More important, has NOAA photographed all 100+ of the new stations, or not? If so, in color, or black-and-white? "John - I'm sure you are aware that the counter from Watts is that the reason that he wants a fuller sample than that used by Menne before writing it up is because the earliest returns of photos of sites were naturally urban - close to the neighbourhoods of volunteers." Researchers have previously compared rural with urban stations and have found no significant difference in trend.
  37. On the reliability of the U.S. Surface Temperature Record
    Leo G at 08:08 AM on 29 January, 2010 The artificially heated thermometer is going to be more or less at equilibrium with the cooler environment it sits in. If it were not able to attain that equilibrium it would not only be in violation of physics but it would continue warming forever, or at least until it burst into flames, melted or whatever. If the environment of the biased thermometer is warmed the equilibrium of the biased thermometer is disturbed, the upshot being that the biased thermometer will reflect changes in the ambient temperature of the greater space it occupies, even when the ambient temperature is still lower than the biased reading of the thermometer.
  38. On the reliability of the U.S. Surface Temperature Record
    Leo G, your third paragraph is incorrect because it has the thermometer acting as the thermostat for the central heater. Instead, put a separate thermostat somewhere else in the room and (somewhat unrealistically) so far away from the light bulb that the thermostat is completely unaffected by the light bulb. That results in the light bulb adding 1 degree to the thermometer, in addition to the ambient air's temperature. So when the ambient air temperature goes from 16 to 18, the thermometer also goes from 16 to 18, but then goes up an additional 1 due to the light bulb. The total is the thermometer reading 19, which is a rise of 2 from the starting value of 17. That is the same rise recorded by the thermometer in the room lacking the light bulb.
  39. Guest post in Guardian on microsite influences
    padruig, that was just mentioned by dhogaza.
  40. On the reliability of the U.S. Surface Temperature Record
    Doug @ 30 - "the lightbulb in the room" mind exercise. (Doug, may I change this a bit, and just for argument sake, I want the light to have a thick metal reflector on it to absorb some of the lights heat energy (yes I'm using an incandescent bulb!), so as to compare to an air field tarmac situation OK?) If the light bulb gets the sensor to read say 17C when the ambient room temp is 16C, then no anomaly will appear until the ambient room temp gets above 17C correct? Take another room also at 16C but no light bulb. With central heating, and both rooms were raised to 18C, then light bulb room would only show a 1C anomaly, whilst no light bulb room would show a 2C anomaly, correct? So though we know in fact that there is a true 2C anomaly, by averaging the two rooms anomalies we only get 1.5C so are thus under reporting by a full 1/2C. So is this what Menne is saying about a cooling bias? But wait, what if at night time, before going to bed, I turned the heat down in my house (again the rooms are at 16C, and sensor one reads 17C, sensor two 16C). Just for argument sake the rooms both loose 1/2C per hour and just for argument, the heat is lowered for 8 hours. Now the room with the sensor that has no light at the time the heat comes back on is reading 12C, but the sensor in the room with the light and heavy metal reflector is at about 13C (yes I grabbed this one out of thin air, but you get my point I hope). Now the combination of both rooms will show a bias towards warmth at about 1/2C. Of course this is a very simple thought experiment, but I hope you get my drift. Sightings really can make a difference. I don’t even want to try to think about a station getting the heat from an air conditioner during the day, then having a large temp drop during that clear starry night! I do not know if the bad sightings create a neg or pos on the anomaly, but it would be good to know in my opinion. Thanx for your time Doug.
  41. Guest post in Guardian on microsite influences
    I'm curious why these discussions fail to address the US Surface Climate Reference Network? An outgrowth of a study conducted in the late 1990's, the USCRN went online in 2003 to address some of the concern about site based bias in measurements. More information is available from NOAA. http://www.ncdc.noaa.gov/crn/
  42. The upcoming ice age has been postponed indefinitely
    I did read it and here is my response: - to attribute glacial periods to simply variations in the earth's orbit is somewhat simplistic given hat there are a lot of other parameters that affect whether glaciation occurs or not. Just having cooler temperatures is not enough - you also need precipitation in the form of snow such that accumulation exceeds melting. In addition to orbital variation, ocean currents and solar & cosmic radiation all factor into the equation.
  43. On the reliability of the U.S. Surface Temperature Record
    In all of the explanations of the trend correlations described between the CRN 1 and 2 vs the CRN 3/4/5 sites, is there an implicit finding that there is a constant bias for a given site and that there is not a stochastic error term which is higher for the CRN 5 vs CRN 1 sites?
  44. Guest post in Guardian on microsite influences
    Alexandre, your reasoning is correct. That and related issues are discussed in the post and comments in the other thread--the one having John's original post, On the reliability of the US Surface Temperature Record.
  45. On the reliability of the U.S. Surface Temperature Record
    trrll @ 79 - Watts and Pielke Snr. are working on a paper. Should be interesting to see what they come up with with double the stations to work with
  46. Guest post in Guardian on microsite influences
    John Congrats on your Guardian article. I think it is an excellent contribution. You also say "Anyway, it's weird excerpting my own writing" to which I reply, when referencing, always reference the best. John
  47. Guest post in Guardian on microsite influences
    Mark J @ 15 - re: Watts?Pielke awaited paper, and so science goes, building, or tearing down, based upon past papers. Seems to work not bad eh?
  48. Guest post in Guardian on microsite influences
    Thanks dhogaza for that clarification. Sounds good.
  49. Guest post in Guardian on microsite influences
    John - I'm sure you are aware that the counter from Watts is that the reason that he wants a fuller sample than that used by Menne before writing it up is because the earliest returns of photos of sites were naturally urban - close to the neighbourhoods of volunteers. I think it is arguable that he and Pielke Snr will get a strikingly different result when they get their turn to use their siting scores with temp data. I guess you didn't mention that because you think it is a weak argument by Watts? I don't think we will have too long to wait to find out.
  50. Guest post in Guardian on microsite influences
    RSVP ... "If a pristine mountain peak in the middle of the Pacific makes sense for monitoring CO2, why not apply similar rigor for weather stations? Instead of trying to salvage this data, maybe better to start from scratch. Dont we have 100 years or so to work on this problem? Much cheaper in the end too." Well, actually, a new temperature monitoring system, designed from the ground up to meet climatology needs, has not only been designed, but deployed. It's called the US Climate Reference Network. In fact, it's the CRN siting criteria that Anthony Watts is using to "prove" that certain stations in the Historical Climate Network are "bad" - using standards set in the last decade to categorize stations that are decades or a hundred years old. One of the results of the Menne 2010 paper is that the several years of USCRN data we have matches the temperatures derived from the historical stations extremely closely. Two separate sets of stations, one set explicitly designed to meet rigorous siting standards and provide optimal spatial coverage. The other a much larger set of stations placed originally to provide data for weather forecasting. And they match. And as years go on and they continue to match, it will only increase the confidence of the accuracy of data from the historical network of stations (though within science it's already sky-high). The historical data has been subject to dozens of tests, and has always passed with flying colors. The only test it hasn't passed is the "I took a photo but did no analysis" test, which is bogus. Not only do we not have 100 years to wait, there's no reason in the world to throw out existing, perfectly good, data - except for the politics of delayed action.

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