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Comments 128951 to 129000:

128951. NewYorkJ at 12:08 PM on 27 January 2009
        There is no consensus
        Back on topic... Published in EOS: http://tigger.uic.edu/~pdoran/012009_Doran_final.pdf Note this isn't a dubious petition or an Inhofe propaganda press release. It's a scientific peer-reviewed study that compares the view of the public with the view of the scientific community on the issue of global warming and the significant human contribution. Details: Among the general public, views are mixed, with about a 57%-38% (Gallup poll) agreement with the significant human contribution. I've seen other surveys with less agreement (particularly among polls conducted during cold winter weather). We see that sort of vehement denial among the blogosphere and various media outlets. This gives the public the false impression that there's a raging debate among scientists on the core issue, creating further doubt. Among scientists, there's very little doubt. The study's authors breaks it down. Among non-climate scientists and non-publishers, there's a 77%-8% (nearly 10 to 1) agreement (the remaining 15% unsure). 8% is pretty small considering the political implications of the topic. This consensus increases among active published scientists to 89%-3%. Among active climate scientists, it's about 97%-1%. The greatest doubt is held by petroleum geologists (what a surprise). Thus, what follows is the key conclusion: "It seems that the debate on the authenticity of global warming and the role played by human activity is largely nonexistent among those who understand the nuances and scientific basis of long- term climate processes. The challenge, rather, appears to be how to effectively communicate this fact to policy makers and to a public that continues to mistakenly perceive debate among scientists."
128952. NewYorkJ at 12:03 PM on 27 January 2009
        There is no consensus
        Re: 116 Actually, if you read the link: http://www.sciencemag.org/cgi/content/summary/297/5585/1287 You'd note the conclusion: "Today's comparatively warm climate has been the exception more than the rule during the last 500,000 years or more. If recent warm periods (or interglacials) are a guide, then we may soon slip into another glacial period. But Berger and Loutre argue in their Perspective that with or without human perturbations, the current warm climate may last another 50,000 years. The reason is a minimum in the eccentricity of Earth's orbit around the Sun. " Ice age cooling, according to this study, won't even begin for tens of thousands of years. But lets say major cooling has already begun. Note how long it takes to reach glaciation. Let's assume it will happen more quickly than recent studies suggest - say 10,000 years. We can expected roughly 6 degrees C of cooling or approximately 0.06 per century. Since global warming is expected to very conservatively warm the Earth about 3 degrees this century on a business-as-usual path (some estimates are much higher), we could count on 2.97 degrees of net warming. Re: 124 Some great minds went against the mainstream many decades ago to propose the hypothesis that human activities would warm the Earth. They were right. Of course, if you examine the quality of minds (measured by the quality of their arguments), that are currently opposing the consensus, you might note that for every theory successfully challenged, there are hundreds that have failed. Failed challenges are often the result of unobjective agendas.
128953. Mizimi at 22:24 PM on 26 January 2009
        It's the sun
        #238 Since the 1970's, there has been a calculated rise in the GMT of around 0.5C most of which is attributed to the effects of man enhancing atmospheric CO2 levels by burning fossil fuels. In order to counter this argument sceptics advance other arguments such as in this thread - namely that the sun is more active and that will cause an increase in solar radiation and thus warm the earth. So it is then necessary to see if such is the case. If there is no apparent rising trend in solar radiation this would negate the sceptics argument. However, like most complicated processes, it isn't always that easy. There are other factors which influence the amount of SR we receive, such as orbital fluctuations (Milankovitch cycles), internal processes in the sun that we 'see' as sunspot activity and the hypothesis of Rhodes Fairbridge ( the Fairbridge 'Curve') etc. Taking a single effect in isolation is an approach adopted by both sides and is counter-productive to a full understanding of the process.
128954. Patrick 027 at 12:32 PM on 26 January 2009
        Volcanoes emit more CO2 than humans
        Re 143: 1. In the work of Spencer we had been discussing, he was using observations over short time periods - not long term climate trends - to attempt to infer the magnitude of climate sensitivity. Some portion of that short term variation occurs in under a year. Because of asymmetries between the hemispheres and also that fall and spring are not just the averages of winter and summer, etc, there will be some annual cycles in some global averages, which result from external forcing but of course involve feedbacks. Spencer also tried to explain most of recent global average surface temperature trends in terms of the PDO and ENSO, I think (it was a strain to do so - in other words, Occam's razor selects against this explanation). There may be an irony there - what positive feedbacks are available to boost internal variability while leaving external forcing so impotent? Of course, there are different spatial-temporal structures in different feedbacks to different things, etc... 2. The 30 year limitation - what limitation, exactly? The satellite data and some other data may only go back to x, but where it agrees with other data we might gain confidence in other data sets going back further; also we have paleoclimate and paleoclimate forcing records, and physics and modeling to fill in some of the blanks. Re 142: Where in the article did you see something besides Milankovitch cycles?
128955. TallDave2 at 04:19 AM on 26 January 2009
        Satellites show no warming in the troposphere
        OK, now extend the GISS/UAH comparison to 2008, and try to tell me we're recording more tropospheric warming than surface warming. http://wattsupwiththat.com/2009/01/18/giss-divergence-with-satellite-temperatures-since-the-start-of-2003/
128956. TallDave2 at 03:54 AM on 26 January 2009
        CO2 lags temperature
        Re: "The economic argument that carbon taxes will damage the US economy is bogus." This is an unknown. It could go either way depending on exactly who is taxed and how much as well as who is hired and how many. No, it's not unknown, it's definitely negative. See "broken windows fallacy." http://en.wikipedia.org/wiki/Broken_windows_fallacy At best, reducing CO2 is an external good that could have benefits 100 years from now (but won't because nothing short of nuclear will stop the growth of emissions in China, INdia, and Africa). At worst it's like paying one guy to dig a hole and another to fill it in.
128957. chris at 10:08 AM on 25 January 2009
        Christmas cartoon on melting North Pole
        What a strange notion Quietman. What lends you to come to that conclusion? Any non-greenhouse contributions to climate/weather variations always apply whether or not the greenhouse effect is augmented, reduced or stays the same.
128958. Quietman at 06:43 AM on 25 January 2009
        Volcanoes emit more CO2 than humans
        Re: "It also occurs to me that Spencer's analysis could be capturing some aspect of the annual cycle." Climate is the average of annual cycles over a given time period. The 30 year limitation currently used skews the results.
128959. Quietman at 06:40 AM on 25 January 2009
        Volcanoes emit more CO2 than humans
        Re: "That's just the Milankovitch cycles." Not Quite. It's a better understanding of various cycles, not just Milankovitch.
128960. Quietman at 06:35 AM on 25 January 2009
        Christmas cartoon on melting North Pole
        chris So you expect me to believe that there are no climate cycles, no medieval warm period, no little ice age, no 60 year PDO cycle, no ENSO, no AMO, no changes in the earths orbit or axial tilt, no changes in the suns effect or the planets effect on the sun and no volcanic or tectonic activity on this planet?
128961. piszkace at 06:20 AM on 25 January 2009
        It's the sun
        Back to the beggining please.- the article and first posts... Could someone explain, why is it so important to see a trend in the suns radiation? Isn't it enough to say that it stabely radiates more than it did a few centuries ago? You don't have to warm more and more to boil the water. It's enough to set your oven to a stable temrature.
128962. Patriot Vet at 06:14 AM on 24 January 2009
        Human CO2 is a tiny % of CO2 emissions
        chris, You say: "And if one considers the 10 million years before the 20th century, the atmospheric CO2 seems to have been pretty much near equilibrium." It appears that you are not up to date on the IPCC science. It has been higher in the past couple of million years. Chapter 6 Palaeoclimate http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter6.pdf "6.3.1 What is the Relationship Between Carbon Dioxide and Temperature in this Time Period? Pre-Quaternary climates prior to 2.6 Ma (e.g., Figure 6.1)were mostly warmer than today and associated with higher CO2 levels." http://www.ipcc.ch/graphics/graphics/ar4-wg1/jpg/fig-6-1.jpg It seems as though you have your facts wrong.
128963. Mizimi at 05:06 AM on 24 January 2009
        Latest satellite data on Greenland mass change
        Maybe strike the 'temporary' #15 there is no mass loss but a change in volume as water is denser than ice.
128964. Mizimi at 05:02 AM on 24 January 2009
        Latest satellite data on Greenland mass change
        Abject apologies to all....I plead a)temporary insanity b)Failing eyesight
128965. Patriot Vet at 04:55 AM on 24 January 2009
        Human CO2 is a tiny % of CO2 emissions
        chris, You say: "And if one considers the 10 million years before the 20th century, the atmospheric CO2 seems to have been pretty much near equilibrium." It appears that you are not up to date on the IPCC science. It has been higher in the past couple of million years. Chapter 6 Palaeoclimate http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter6.pdf "6.3.1 What is the Relationship Between Carbon Dioxide and Temperature in this Time Period? Pre-Quaternary climates prior to 2.6 Ma (e.g., Figure 6.1)were mostly warmer than today and associated with higher CO2 levels." http://www.ipcc.ch/graphics/graphics/ar4-wg1/jpg/fig-6-1.jpg It seems as though you have your facts wrong.
128966. black2deep at 02:32 AM on 24 January 2009
        It's the sun
        Just so you don't think I am making this up. http://www.mobilemag.com/content/100/344/C2179/ March 13, 1989 - The Quebec Blackout Storm - Astronomers were busily tracking "Active Region 5395" on the Sun when suddenly it disgorged a massive cloud of superheated gas on March 10, 1989. Three days later, and seemingly unrelated to the solar paroxicism, people around the world saw a spectacular Northern Lights display. Most newspapers that reported this event considered the spectacular aurora to be the most newsworthy aspect of the storm. Seen as far south as Florida and Cuba, the vast majority of people in the Northern Hemisphere had never seen such a spectacle in recent memory. At 2:45 AM on March 13, electrical ground currents created by the magnetic storm found their way into the power grid of the Hydro-Quebec Power Authority. Giant capacitors tried to regulate these currents but failed within a few seconds as automatic protective systems took them off-line one by one. Suddenly, the entire 9,500 megawatt output from Hydro-Quebec's La Grande Hydroelectric Complex found itself without proper regulation. Power swings tripped the supply lines from the 2000 megawatt Churchill Falls generation complex, and 18 seconds later, the entire Quebec power grid collapsed. Six million people were affected as they woke to find no electricity to see them through a cold Quebec wintry night. People were trapped in darkened office buildings and elevators, stumbling around to find their way out. Traffic lights stopped working, Engineers from the major North American power companies were worried too. Some would later conclude that this could easily have been a $6 billion catastrophe affecting most US East Coast cities. All that prevented the cascade from affecting the United States were a few dozen capacitors on the Allegheny Network. [Newspaper Archive] June 6, 1991 - Severe sun storm threatens utilities [New York Times, June 6, 1991, p. A16]. July 15, 2001 - The Bastille Day Storm - Solar flare threatens the earth with storm [New York Times, July 16, 2001 p. 21]. Minor damage reported from geomagnetic storm [New York Times, July 17, 2001 p. A17] October 29, 2003 - The Halloween Storm - This Halloween Storm spawned auroras that were seen over most of North America. Extensive satellite problems were reported, including the loss of the $450 million Midori-2 research satellite. Highly publicized in the news media. A huge solar storm has impacted the Earth, just over 19 hours after leaving the sun. This is one of the fastest solar storm in historic times, only beaten by the perfect solar storm in 1859 which spent an estimated 17 hours in transit. A few days later on November 4, 2003 one of the most powerful x-ray flares ever detected, swamped the sensors of dozens of satellites, causing satellite operations anomalies….but no aurora. Originally classified as an X28 flare, it was upgrade to X34 a month later. In all of its fury, it never became a white light flare such as the one observed by Carrington in 1859. Astronauts hid deep within the body of the International Space Station, but still reported radiation effects and ocular 'shooting stars'. http://www.foxnews.com/story/0,2933,236333,00.html The biggest solar flare in decades has put satellite operators battening down the hatches in preparation for a severe geomagnetic storm on Wednesday. The eruption is the latest event in a week of intense solar activity. The activity is highly unusual because the 11-year sunspot cycle peaked in 2000. The latest flare erupted from a large sunspot at 1154 GMT on Tuesday. It was the first in the latest bout of turbulence to launch its charged particles directly toward the Earth. "This is the strongest flare we've seen in the past 30 years," said Leon Golub, an astrophysicist at the Harvard Smithsonian Center for Astrophysics. The website spaceweather.com lists it as third highest ever recorded in X-ray flux. Late on Tuesday, the US National Oceanic and Atmospheric Administration predicted a severe geomagnetic storm would follow, with intervals of extreme intensity possible. The agency warned of possible disruptions to satellite operation, electric power systems and failures of high-frequency radio communications and satellite navigation systems. Celestial fireworks The main mass of charged particles should hit the Earth's magnetosphere about 30 hours after the flare, about 1800 GMT on Wednesday. Celestial fireworks in the form of aurora will follow as the energetic particles interact with the Earth's magnetic field. Impressive auroras are likely at latitudes much lower than normal. The fluctuations caused in the magnetic field affect electronic systems and power grids by inducing currents in conductors. The severity of the storm and its impacts on electronic equipment will depend on the orientation of the magnetic fields in the ejected particles, relative to the Earth's magnetic field. If the particles' fields oppose the Earth's, the interaction will be extremely intense. But a parallel direction will reduce the impact. Present instruments cannot measure that orientation until the particles hit. The possible effect on electric power grids is a significant concern after this year's major blackouts in the US and Italy. Geomagnetic storms can induce voltage fluctuations that destabilise vulnerable power grids. Tuesday's flare is larger than the 1989 storm that knocked out the Quebec power grid. Shut down The influx of particles can also build up potentially damaging charge levels on satellite surfaces, and disrupt operation of their navigation, orientation and sensor systems. Worried satellite operators begun shutting down instruments to protect them from overloads on Tuesday. "Geosynchronous communications satellites are likely to be affected," warned John Kohl, a solar astrophysicist at Harvard-Smithsonian, who shut down his own ultraviolet experiment on the Solar and Heliospheric Observatory (SOHO) soon after learning of the flare. Disruption of navigation and communications satellites could hamper crews fighting wildfires in southern California, where the fires have destroyed cell phone towers and smoke obstructs visual navigation. But astronauts on the International Space Station are expected to weather the storm safely, and the atmosphere will shield people on the ground from potentially harmful radiation. BUt our chart makers would have us believe that solar flair activity has actually fallen. I suppose they don't think we listen to the news or pay attention so it is easy to slip one over on us and basicly LIE! Okay they don't lie, they just bend the truth to fit thier needs.
128967. black2deep at 02:03 AM on 24 January 2009
        It's the sun
        Okay I am in radio, and solar flair activity over the last 10 years has been horrible. Just two years ago the news was reporting unusually high solar flair activity. Numerous articles were published about the sun spot cycle being totally confusing and overly active. But the chart says that solar flair activity is down? So? Anyone want to tell me just who it blowing what kind of smoke and where? If you really want to find out about solar flair activity and its rise in the last ten or so years then go to the source. http://www.nso.edu/ This is the national solar observatory in Sun Spot New Mexico. They are the last word in the suns activity. I can make a chart and with a little credablity I can sell it to you. Does it make it ture? No it doesn't, but what it does do is negate the argument and cloude the facts.
128968. Philippe Chantreau at 15:39 PM on 23 January 2009
        Climate change on Mars
        Olympus Mons, I did some of your work for you: http://www.uapress.arizona.edu/onlinebks/mars/chap04.htm Excerpt:"Seasons are of unequal length. Mars is closest to the Sun in southern summer/ northern winter, and furthest in southern winter/northern summer. The southern hemisphere has shorter, warmer summers and longer, colder winters. During southern summer, dust storms often circle the entire planet." Which brings us back to this article: http://www.nature.com/nature/journal/v446/n7136/abs/nature05718.html Outstanding pics on this presentation: http://cpt.phys.utk.edu/~th/Astro151/Lecture12.pdf More info here: http://www.msss.com/http/ps/seasons/seasons.html. http://www.uapress.arizona.edu/onlinebks/mars/chap04.htm http://www.sciencemag.org/cgi/content/abstract/228/4704/1160 http://www.sciencemag.org/cgi/content/abstract/228/4704/1160 http://www.sciencemag.org/cgi/content/abstract/228/4704/1160
128969. Philippe Chantreau at 15:14 PM on 23 January 2009
        Is Antarctic ice melting or growing?
        RC has a new interesting thread about Antarctica: http://www.realclimate.org/index.php/archives/2009/01/state-of-antarctica-red-or-blue/langswitch_lang/th The Nature article is here: http://www.nature.com/nature/journal/v457/n7228/full/nature07669.html
128970. Patrick 027 at 15:10 PM on 23 January 2009
        Volcanoes emit more CO2 than humans
        "Earth's Orbit Creates More Than A Leap Year: Orbital Behaviors Also Drive Climate Changes, Ice Ages ScienceDaily (Feb. 18, 2008)" http://www.sciencedaily.com/releases/2008/02/080213113037.htm That's just the Milankovitch cycles. It's basic grade-school science. Nothing new here. "There is an apparent agreement with Fairbridge" Well, according to "Article" from comment 139, Fairbridge was an early supporter of the Milankovitch cycle-driven climate changes concept. But that doesn't do anything to bolster his other concepts about solar jerk and sizable sudden sea level changes in the later Holocene. Also, "Article" did imply that the Fairbridge curve had been accepted in some way, but I don't buy that in full. Of course I wouldn't be surprised if sea level changes have some irregularity or even smaller cycles in them; there's no rule about having to rise completely monotonically (never reversing) between the peak of the last ice age and the present. But that's different then accepting the Fairbridge curve.
128971. chris at 05:43 AM on 23 January 2009
        Christmas cartoon on melting North Pole
        re #16: Not really Quietman, the essential conclusions of the original Mann et al. palaeoproxy analyses in relation to the anomalous nature of late 20th century and contemporary warming are independent of whether or not tree ring proxies are used: e.g. M. E. Mann et al. (2008) Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia Proc. Natl. Acad. Sci. 105:13252-13257 In which over 1,200 proxy series were used to assess millenial scale temperature. In fact the data are now rather firmer in relation to our understanding of the anomalous nature of current warming compared to the last 1300 years. The conclusions are prety much the same if the tree ring series are left out, except that they don't extend back to 1700 years into the past (which is possible using tree ring data). And of course tree ring proxies are only used under specific conditions that the tree species and locales are not moisture-limited but are temperature-limited (generally highish latitudes and highish altitudes...
128972. Philippe Chantreau at 04:31 AM on 23 January 2009
        Christmas cartoon on melting North Pole
        Marc Morano is a politician of the worst kind: a PR professional. I don't trust anything he writes. The so-called "growing surge" exists only in his pathetic mind manipulation effort. Morano is scientifically illiterate, so is Inhoffe. If you don't even trust Wikipedia because, in your own words, it is too politicized, why would you give any attention to Morano and Inhoffe, who are about nothing but politics and have not a clue about science? Hansen is entirely justified to denigrate nincompoops who have no idea of what they're talking about and merrily go on accusing him of fraud every time they have a chance.
128973. Quietman at 03:15 AM on 23 January 2009
        Christmas cartoon on melting North Pole
        Philippe My point was if we use the Rainfall/Drought data it contradicts the use in the ol' hockey stick. Ps This is interesting: NASA's James Hansen calls climate skeptics court jesters In the face of this growing surge of scientific research and the increasing number of scientists speaking out, NASA scientist James Hansen wrote this past week that skeptics of a predicted climate catastrophe were engaging in “deceit” and were nothing more than “court jesters.” “The contrarians will be remembered as court jesters. There is no point to joust with court jesters. They will always be present,” Hanson wrote on August 16, 2007.
128974. Quietman at 03:11 AM on 23 January 2009
        Climate sensitivity is low
        Do you mean this paper? HEAT CAPACITY, TIME CONSTANT, AND SENSITIVITY OF EARTH'S CLIMATE SYSTEM by Stephen E. Schwartz
128975. Quietman at 02:17 AM on 23 January 2009
        Volcanoes emit more CO2 than humans
        ps Here is another example from a different scientist. There is an apparent agreement with Fairbridge: Earth's Orbit Creates More Than A Leap Year: Orbital Behaviors Also Drive Climate Changes, Ice Ages ScienceDaily (Feb. 18, 2008) — The Earth's orbital behaviors are responsible for more than just presenting us with a leap year every four years. According to Michael E. Wysession, Ph.D., associate professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, parameters such as planetary gravitational attractions, the Earth's elliptical orbit around the sun and the degree of tilt of our planet's axis with respect to its path around the sun, have implications for climate change and the advent of ice ages.
128976. Patrick 027 at 16:16 PM on 22 January 2009
        Arctic sea ice melt - natural or man-made?
        ... The Cushman-Roisin solution is not intended to be a complete description of such waves (baroclinic planetary or Rossby waves in general) - just to illustrate the basic concept. It might (?) more readily apply to the ocean where density variations are a small percentage of total density.
128977. Mizimi at 05:02 AM on 22 January 2009
        Do cosmic rays cause clouds?
        This thread asks a question - 'do cosmic rays cause clouds?', which somehow has transmogrified into are CR's responsible for global warming. Usoskin stated "Cosmic radiation induced ionisation is not the main source of cloud formation but rather modulates it and the long-term trend results from other processes, which are outside the main focus of this study. So clearly there IS a body of opinion that CR's DO affect (not effect) cloud formation.
128978. FerdiEgb at 23:37 PM on 21 January 2009
        CO2 lags temperature
        Sorry for the (very late) drop by! I was informed about this page by a reference from a recent discussion... No problem with the first statement: During ice ages/interglacials there is a lag of CO2 after temperature changes of 800 +/- 600 years in upgoing parts and several thousands of years during falling years with a sensitivity of about 800 ppmv/°C. This reduces to about 50 years lag for the MWP-LIA transition (again about 8 ppmv/°C) and 1 to a few months around the upgoing trend today (with about 3 ppmv/°C). But a big problem with the second statement: "The CO2 record confirms both the amplifying effect of atmospheric CO2 and how sensitive climate is to change." The amplifying effect of CO2 is difficult to estimate, as most of the time there is an overlap between the upgoing and downgoing trend of temperature and CO2. But there is an interesting exception: the end of the previous warm(er) period: the Eemian. The CO2 levels remained high while the temperature (and methane levels) dropped to a minimum value and ice sheets did grow again to a maximum. The subsequent decrease of 40 ppmv CO2 doesn't show any measurable drop in temperature outside the error margins. The theoretical change with 3°C/2xCO2 should give a drop of 0.4°C, and that is not visible in the ice core record. That means that the 3°C/2xCO2 is probably overblown. See: http://www.ferdinand-engelbeen.be/klimaat/eemian.html A second graph which shows that there is not that much feedback from increased CO2 on temperature, is from the very detailed Epica C ice core. The influence of temperature on CO2 (with lag) is clearly visible, but the influence of CO2 on temperature is clearly... absent. That is remarkable for what is assumed to be responsable for about 40% of the increase in temperature... See: http://www.ferdinand-engelbeen.be/klimaat/klim_img/epica5.gif With thanks to Andre van den Berg who made the graph. Thus the science about the feedback and sensitivity of the climate for CO2 changes is far from settled...
128979. Philippe Chantreau at 16:45 PM on 21 January 2009
        Christmas cartoon on melting North Pole
        OK. I'm aware of that. In temp reconstructions, they are used somewhat differently, as temp proxies. Sjkhayes had a problem with dendro data as temp proxies. I just pointed that there are other proxies.
128980. Wondering Aloud at 08:13 AM on 21 January 2009
        Is Pacific Decadal Oscillation the Smoking Gun?
        Where is this one at? I think I sam a claim that PDO was back into a neutral phase and that the it never really switched for any significant time? When you present global temperature anomaly graphs like the one above who is the source of these graghs? Do the ones you use now look the same as they did a few years ago for the period from 1880 to 1990?
128981. Quietman at 07:55 AM on 21 January 2009
        Christmas cartoon on melting North Pole
        Philippe The tree rings aerve a better indicator of time of drought and times of plentiful rainfall. When there is plenty of moisture they grow faster and sequester more carbon via CO2 intake. In times of drought they can't.
128982. Wondering Aloud at 06:55 AM on 21 January 2009
        Arctic sea ice melt - natural or man-made?
        Patrick 027 I do agree with you in your post 407. That is not only proper it is important, I was just pointing out that just because it is cited doesn't mean it is supporting everything said, or even that it is anything additional. I found that I had to know the citations in great detail to evaluate the paper. I am sure this is why we have to specialize so much.
128983. Patrick 027 at 16:03 PM on 20 January 2009
        Arctic sea ice melt - natural or man-made?
        Of course, other waves (or patterns of linear superpositions of waves) with mj for non-integer j values can exist, but they won't form a steadily-propagating pattern in the horizontal direction - they will interact with the boundaries of the fluid to produce reflected waves, which aren't part of the same pattern, so the pattern evolves. And there is a gap in the m spectrum between m0 and -m0. OTHER THOUGHTS: 7. It occured to me that the IPV distribution at a fluid boundary (as opposed to within the fluid) due to the potential temperature (q) gradient along that surface, might be described in terms of an 'image IPV' (? like an 'image charge' in electrostatics ?) that exists somewhere below the boundary, with the condition that the air doesn't cross the boundary between the real fluid and the image fluid. Along the same lines, the reflection (partial or complete) - if that's what it is - of the RV field of an IPV anomaly, off a boundary, might be due to an image IPV on the other side of the boundary that is a reflection of the IPV anomaly. But the image IPV is seen only from the side of the boundary it doesn't exist in (or else it has different effects where it is placed than from where it can be seen as a reflected image) ... haven't done the math on this idea, yet... 8. A planetary wave, depending on the basic state f variation, is modified by nonzero S but clearly depends on the basic state f gradient. A topographic Rossby wave has an IPV gradient that is due to variation of Hzd (or surface pressure) of the fluid due to bottom topography. (Barotropic Rossby waves with an IPV gradient due to RV variations could be said to be due to the 'topography' of the top of the fluid - which corresponds to variations in pressure on a geopotential (constant z) surface.) In the presense of nonzero S, the bottom topography intersects isentropic surfaces that are horizontal in x,y,z, or typically nearly so in x,y,p coordinates. It could be seen as altering the basic state fluid depth of individual isentropic layers where it intersects them. The IPV gradient could be said to be at the surface. There is thus a similarity between topographic Rossby waves and Rossby waves propagating due to a temperature (and thus potential temperature) gradient along a non-sloping (in x,y,p or perhaps x,y,z) bottom surface. And both should have amplitudes enhanced towards the surface. --------- About surface amplitude enhancement or reduction for topographic or surface q-gradient Rossby waves verses planetary waves, respectively - this is relative to the variation in amplitude with height that may occur because of basic state varyiations, in particular decreasing density. This effect was not covered by the baroclinic Rossby wave description from Cushman-Roisin, but Holton has solutions with constant vertical wavelength in z coordinates which increase in amplitude with height roughly in proportion to the inverse square root of density. Energy per unit mass is proportional to the square of amplitude, and thus given the solution from Holton, is inversely proportional to density. This implies constant energy per unit volume. For constant vertical wavelength with height, this implies constant energy per wavelength. Given the conditions for that solution, I think that Rossby waves with upward group velocity concentrate energy into smaller masses as the energy propagates upward. This is reversable, in the sense that energy per unit mass declines with downward propagating energy (it is not an aspect of an instability or dissipation of the wave).
128984. Patrick 027 at 12:32 PM on 20 January 2009
        Arctic sea ice melt - natural or man-made?
        Various notes: 1. In the expression for Ross, as in the formulae for Rossby radii of deformation, f could be replaced with f_loc if one is using a gradient wind balance instead of a geostrophic balance. 2. "'time step'**" - The secondary circulation (SAAC) obviously starts to occur as soon as MF or TF start to disrupt geostrophic (or gradient wind) balance. Rossby waves and other quasigeostrophic phenomena can be described witht the approximation that SAAC occurs to completion instantaneously (because it is faster than the quasigeostrophic advection that may contribute to MF and TF in a range of spatial and temporal scales). Using a time step where MF and TF occur without SAAC and then allowing SAAC to occur is just a way to illustrate cause and effect. Of course, using many small time steps, as in numerical integration or a computer model, can approximate the process. In reality, if there were a sufficently sudden MF and/or TF, the SAAC would over-react - it would tend to oscillate about a balanced-wind equilibrium. Within a closed space this could involve oscillation through the same conditions; but more generally, the oscillation at the source decays as inertio-gravity waves (or Kelvin waves if the situation calls for it) are radiated outward. Because these waves have some energy, but the resulting balanced state should be the same whether the changes are sharp or gradual, I suspect it must take some additional energy to force a sudden change, which suggests the fluid may tend to resist such change (?). One can see how a gradual change avoids producing significant inertio-gravity or Kelvin waves by using the approximation of many small time steps. A set of such ageostrophic waves are emitted at each time step, but the change at each step is small, so the emitted waves should be small as well. In addition, over many time steps, many sets of waves would be emitted that are not in phase with each other, thus not leading to greater and greater amplitudes over time. Changes that are gradual relative to the period of the ageostrophic waves can thus avoid significant emission of those waves (PS a similar argument can be used in describing why reflection is stronger off a boundary in space when it is sharp relative to wavelength - that may come up if I ever get to Rossby wave refraction.) But it would take some specific conditions to completely avoid emission of such ageostrophic waves - not accounting for those waves is one of the approximations that can be used in studying slower quasigeostrophic processes. 3. The MMC, including adiabatic response to diabatic forcing, is a zonally averaged SAAC. Thus the MMC due to the RVad (due to part of the u'v' of the EP flux**) and the MMC due to qad (which is the v'T' of the EP flux) will be equal, in the same direction. The MMC of a SSW is poleward at and around the level of EP flux convergence, but there is adiabatic warming below poleward, etc, so the RVad would have to 'win out' in that case if RVad were the dominant part of MF. Of course, the other important part of MF (except near the surface) comes from the variation in f, and planetary vorticity (f) advection often dominates over RV advection. The diabatic portion of TF that may occur with an SSW will tend to be, as I understand it, a response to the SSW. The warming of the polar stratosphere drives a diabatic cooling, which causes additional MMC in the same direction as that which occurs as part of the SSW. 4. **Question - Did the analysis of comment 412 imply that, where RV and/or temperature variation contributes to the basic state IPV gradient, that there is some intermediate wavevector for which there is no propagation? This seems odd - but I have to set that aside for now. 5. The three dimensional wave vector = [k,l,m], where m equals 2*pi/(vertical wavelength). m can be given in terms of different units depending on the vertical coordinate being used (z, p, q, etc.). Downward phase propagation occurs with m < 0. 6. The analysis of comment 412 applies to vertical variations in MF. I think a properly-weighted vertically-average of MF could be subtracted from all levels so that the remaining MF is the vertically-varying MF that occurs with a TF (when W and Q are not undefined - that is, when there is some nonzero RVad and qad) and to which comment 412 applies. The vertically-averaged MF would cause some SAAC that tends to produce cold-core lows and warm-core highs (weaker at lower levels). The total vertical scale of the fluid places an upper limit on the vertical scale of any wave or other phenomenon. ------- For example, for planetary waves (specifically, IPV gradient due only to variations in f, with the gradient in the positive y direction) in a fluid with nonzero S, Cushman-Roisin finds the dispersion relation: w = - beta * k / [ k^2 + l^2 + m^2 * f0 / N^2 ] where N is the buoyancy frequency and N^2 is proportional to S for a given p or z, etc, and f0 is a representative f for a beta-plane. The solution was for waves that propagate horizontally but are standing waves in the vertical direction, of the form: 2 * cos(m*z) * cos(k*x + l*y - w*t) But this is the linear superposition of two baroclinic waves of opposite vertical tilts: cos(k*x + l*y + m*z - w*t) and cos(k*x + l*y - m*z - w*t) so the two wave vectors are [k,l,m] and [k,l,-m]. But they have the same w and the same dispersion relationship (which is independent of the sign of m) applies. This is for x,y,z coordinates for a fluid with definite top and bottom boundaries. For total fluid depth Hzd (d for depth, z for the vertical coordinate), there are a set of allowable m values (Because this was for waves that are standing in the vertical direction): m = m0, m1, m2, ... (and also negative m values of the same magnitudes) where m0 ~= N/sqrt(g*Hzd) and for j = 1,2,3 ... mj = j*pi/Hzd Putting these into the dispersion equation, one finds that the m0 wave has the same dispersion relation as a barotropic wave, w = - beta * k / [ k^2 + l^2 + 1/R0^2 ], where R0 is the external Rossby radius of deformation for Hzd, f0, and g, and the mj waves have the dispersion relation: w = - beta * k / [ k^2 + l^2 + 1/Rj^2 ], where Rj is the internal Rossby radius of deformation for Hzj, f0, and N, where Hzj = vertical wavelength / 2*pi = 1/mj. And, R0 is also equal to the internal Rossby radius of deformation for Hz0 = vertical wavelength / 2*pi = 1/m0. This seems to make sense so far. How does the dispersion relationship look when graphed in three dimensions, k, l, and m? The surfaces of constant w form ellipsoids; if the m dimension is scaled by some other factor, they appear as spheres. A cross section parallel to the k,l plane at a nonzero m has the same shape as the graph of w over k,l for the barotropic waves discussed in comment 361; for such a plane at m = +/- m0, the graph is exactly the same. Any cross section taken parallel to the k axis looks similar and can be made to appear the same with stretching or contraction along axes - with one exception: cross sections along the k axis, which pass through the origin where m and l are also 0. The difference there is that w goes to inifinity approaching the origin from negative k values, but all contours of w go through the origin. Other cross sections parallel to the k-axis appear similar at large wavenumbers, but at small wavenumbers, the difference is that there is a finite maximum in w along the k axis at a negative value of k. With some differences for wave vectors with m and l equal to zero, there will thus be similar patterns in group velocity and phase speed within any plane parallel to the x-axis. BUT, for the solutions from Cushman Roisin, m = 0 is not allowed, only +/- m0, m1, m2, ... etc, because these are components of standing waves in the vertical direction, with the waves of m > 0 being produced by the waves of m < 1 and vice-versa upon reflection (with the vorticity wave in phase with incident wave)from the top and bottom boundaries - or that's what I thought. But this is only approximately true for j = 1,2,3, ... and not true m0. The number of vertical wavelengths that can fit into the total fluid depth Hzd for standing waves reflecting in phase must be an integer multiple of 1/2. To a first approximation, the number of vertical wavelengths that fit is equal to j * 1/2, but it is actually somewhat more (the vertical wavelengths are somewhat less) and the difference increases for smaller j values (larger vertical wavelengths). For such standing waves resulting from reflections as just described, the j = 0 wave ought to have an undefined vertical wavelength - essentially an infinite wavelength, with m = 0. But in the dispersion relationship, that would be a barotropic wave with infinite frequency and phase speed in the horizontal direction. Instead, the barotropic Rossby wave has to be reconstructed from the linear superposition of waves with m = m0 and m = -m0. They are in phase at the lower boundary (the surface if in the atmosphere) but they are not in phase at the upper boundary, so the wave is strongest at the surface and decreases in amplitude with height. **This is problematic - it implies warm core lows and cold core highs, the pattern expected for topographic Rossby waves with nonzero S. The pattern expected for planetary Rossby waves (depending only on variation of f) with nonzero S is for amplitude to be reduced near the surface. So I'm not sure about this...**
128985. Quietman at 05:51 AM on 20 January 2009
        Volcanoes emit more CO2 than humans
        Patrick Wikipedia Entry Article A quick web search provides many more links.
128986. Philippe Chantreau at 04:26 AM on 20 January 2009
        Christmas cartoon on melting North Pole
        You can try leaving tree rings out altogether, there are other methods: http://www.geo.lsa.umich.edu/climate/ The latest Mann paper has all data and code available. GISSTEMP code was made available a long time ago.
128987. sjkhayes at 02:55 AM on 20 January 2009
        Christmas cartoon on melting North Pole
        Sear sir or madam: I recently came across the “great hockey stick controversy” and I am trying to find a well argued view of it from those who favour the climate consensus of human induced global warming. I came across your site and while I find it very good in its rebuttals, it does not, it would seem to me, answer what I would call the “ah buts.” That is to say you present good rebuttals, but it seems that the detail of the criticism is not addressed. The background here is that prior to coming across this controversy, I was leaning towards the view that global warming was human induced, but the hockey stick controversy has severely dented this view. So here are the rebuttals and the "ah buts" that I would be very grateful if you to please assist me by adressign the "ah buts" yourself, or pointing me to where they are addressed. ============== Rebuttal 1: The NCR review initiated by the National Academy of sciences in 2006 vindicated Mann’s original 98 hockey stick work, albeit with some reservations. Ah but 1: The NCR panel was biased but even then they agreed with the McKittrick and McIntyre criticism that Mann’s 98 methods produced a hockey stick shape when random red noise was applied to it. I read the report and the graph showing this is in there. Surely this makes a nonsense of Mann’s 98 work. ============== Rebuttal 2: The Hockey stick has been confirmed by other subsequent studies as evidenced by the NCR report. Ah but 2a: Most of the other studies use the same set of contested trees from the south west United States and the polar urals that the NCR panel should said should not be used. If you remove the contested trees, the hockey stick disappears and the Medievel Warm Period and Little Ice Age reappear. Ah but 2B: The confirmation work has all (or mostly) been done by associates of Mann. ============== Rebuttal 3: If you remove the contested trees from the analysis, yes the medieval warm period exists, but the late 20th century is still significantly higher than it was then. Ah but 3: The studies maintaining this splice the instrumental record on to the tree ring record from about 1980 on. If the tree ring record was continued to today, the tree ring proxies would show a fall in temperature. I.E. they would diverge giving us what is called the divergence problem in the debate. ============== Rebuttal 4: Amman and Wahl’s paper from 2006 (or was it 2007) was a key piece of confirmatory evidence. Ah but 4a: The IPCC bent the rules to allow it into the Fourth Assessment report. Ah but 4b: Amman and Wahl refused for three years to release the R2 statistic that would have shown that their study was unreliable. Eventually they came up with a mumbo jumbo justification to say that the R2 statistic was irrelevant. ============== Rebuttal 5: Mann’s 2008 paper has reproduced the hockey stick using 96 different proxies. Ah but 5b: If you take out the contested trees from the south west United States and the proxies from the Tiljander lake whose original authors said were corrupted, then the hockey stick disappears and the Medievel Warm Peirod and Little Ice Age come back. ============== One other point that you might help me to address is to come up with a justification for the reluctance of climate researchers to release their data, method and source code other than “do your own research”. If this could be justified for publicly funded research, even better. Many thanks Shane
        Response: Discussion on the hockey stick is best conducted on the hockey stick page. And yes, that page does need updating considering the latest study on the topic coming out last year (it's on my to-do list).
128988. Mizimi at 02:03 AM on 20 January 2009
        We're heading into an ice age
        QM: have you read this, and if so, any comment? http://www.griffith.edu.au/conference/ics2007/pdf/ICS176.pdf How's the greehouse project?
128989. Mizimi at 01:34 AM on 20 January 2009
        It's not bad
        Millions of years ago, climate conditions were such that plant life grew rapidly on a global scale. CO2 and WV levels were high enough to sustain this growth and during this period much of the FF's we now burn were laid down. Plant life sequestered CO2 and locked it up as FF, thereby reducing the CO2 levels, although at times, 'natural' events such as vulcanic erutions/forest fires would have temporarily offset this sequestration. The end result is that CO2 levels hit (possibly) an all time low of around 200ppm and stayed there. As this level is close to the minimum C3 plants can tolerate, further growth and investment of new habitat were resticted. At this time, only C3 plants existed (fossil records of C4 plants indicate their emergence around 8mya) and C3 plants, in order to prosper, require CO2 levels higher than 200ppm. If the levels fall below this figure, then growth effectively halts as does sequestration. One can argue that the emergence of C4 plants was 'caused' by persistent low levels of CO2 - an adaptation of metabolic process to environmental pressures - and since they are more efficient in their use of CO2,(they had to be) they began to colonise and modify habitats where C3 plants could no longer compete effectively. C4 plants are grasses, and include the cereals. The rise of civilisation was made possible only because of these plants and man's ability to husband them, so we actually owe our existence to low levels of atmospheric CO2. Current concern is directed at enhanced CO2 levels through burning FF's, and the (modelled) effects this may have on climate, and the consequent impact on man's habitat. The current level of around 380ppm, whilst nearly double that during the period C3 plants were dominant, is still towards the lower level of tolerance for them. It can therefore be argued that further increases of CO2 will be beneficial to this class of plants and not detrimental to C4's until levels exceed 1000ppm; in other words, our CO2 emissions are helping C3 plants, and quite possibly helping (in some small way) to offset the losses incurred by de-forestation. Yes, they may be disadvantages to mankind and his preferred lifestyle/habitat from CO2 enhancement, but there are benefits to the biosphere at large.
128990. Patrick 027 at 16:18 PM on 19 January 2009
        Arctic sea ice melt - natural or man-made?
        In a quasigeostrophic approximation: In isobaric coordinates x,y,p: Following the air as it moves: As mentioned in comment 411, the change in vertical wind shear driven by momentum (wind) advection by geostrophic wind shear (Let's call this 'momentum forcing' - MF, in this context) is the opposite of the change in geostrophic wind shear driven by the Laplacian in the horizontal (sum of second derivatives in horizontal dimensions - aka 'curvature') of the temperature change driven by temperature advection (let's call this the 'thermal forcing' - TF, in this context). Both TF and MF make equal contributions to ageostrophic vertical wind shear: MF by changing the wind shear, and TF by changing the geostrophic wind shear in the opposite direction. The relative vorticity (RV) is the vertical component of the curl of the wind velocity vector, equal to the Laplacian of the streamfunction in the horizontal plane (horizontal being along an isobaric surface in x,y,p coordinates). And so the same is true for the variation of RV over height (over p in isobaric coordinates): Both MF and TF create equal ageostrophic vertical RV variation - MF by channging the vertical RV variation, and TF by changing the geostrophic vertical RV variation in the opposite direction. BUT One can add to MF the effects of advection of planetary vorticity - north/south winds in the presence of nonzero beta, and frictional/viscous torques. One can add to TF diabatic heating. Thus, the total MF is from the vertical variation (vertical derivative) of the sum of: the advection of RV, the advection of f, and the curl of viscous acceleration. And the total TF is from the Laplacian of the sum of: the temperature advection and the diabatic heating. For quasigeostrophic balance, vertical derivative of RV = -G/f * Laplacian of q where G = R/p * T/q where R is the gas constant for air, And for a given p, T/q = (p/p1000)^(R/cp) where p1000 = 1000 mb (a reference pressure level) and cp is the specific heat of air at constant pressure For the purposes of a simple scale analysis, this relationship can be written roughly in terms of a height scale H (Hp, in pressure coordinates), and length scale L, as RV/Hp ~ G/f * q/L^2 where the negative sign was dropped by assuming Hp is measured upwards (the direction of decreasing pressure). (~ can be read: "scales as" and/or "is of the same scale as") The change in vertical variation of geostrophic RV due to advection of q (proportional to the advection of T as a function of pressure: q = T*(p1000/p)^(R/cp)) is opposite the change in vertical variation of RV due to RV advection - this can be written advected RV /Hp ~ - G/f * advected q /L^2 ... Assume H = Hp for the rest of this comment: ... Well, without dragging everyone through the algebra, this implies (with conservation of IPV, where IPV/g = AV*S, S being del(q)/del(p) and AV = RV + f), where total (RV advection + f advection + curl of viscous acceleration)/H = W * RV advection/H Thus total MF = W * MF from vertical variation of RV advection and similarly, total TF = Q * TF from Laplacian of q or T advection: --- The balance equation and relationship between MF and TF can be solved for vertical motion: in terms of q advection, qad: vertical motion ~ (Q+W)*G/f * H^2/L^2 *qad } / [ G/f * H^2/L^2 * S + AV ] and in terms of RV advection, RVad: vertical motion ~ -{ (Q+W)*RVad*H } / [ G/f * H^2/L^2 * S + AV ] Vertical variation of vertical motion in pressure coordinates, in a hydrostatic approximation, requires horizontal convergence and divergence. This is the secondary adiabatic ageostrophic circulation. The Laplacian of vertical motion changes the Laplacian of q by moving q surfaces relative to p surfaces (adiabatic cooling and warming). The horizontal convergence and divergence changes AV (and thus changes RV, since, after a 'time step'**, f doesn't change because at an instant the air doesn't move and f is fixed at a given location) while conserving IPV; vertical stretching reduces S. This secondary adiabatic ageostrophic circulation (SAAC) brings the actual RV closer to geostrophic RV, both by (at least when assuming both W and Q are positive) reducing the RV changes forced by MF and reducing the q changes forced by TF. Notice that if W and Q are of the same sign, MF and TF cause SAAC of the same direction. If both changes in RV and q are reduced, it is possible for the net changes to be zero. But one effect could be said to 'win' if it is not zero. Substituting the vertical motion back into the balance equation: FOR Ross = G * H^2/L^2 * S/(AV*f) : balanced change in RV ~ RVad * [ W - (Q+W) / ( Ross + 1 ) ] balanced change in q ~ qad * [Q - (Q+W) / ( 1 + 1/Ross ) ] AND balanced change in IPV/g (where S is a basic state value) ~ RVad * S * ( W - Q / Ross ) Thus, for positive W and Q, the effect of RVad 'wins out' over qad in both balanced RVad, qad, and IPV changes, when Ross >~ Q/W whereas qad wins when Ross <~ Q/W Of course W and/or Q could be negative as well, in which cases ... - etc. It might seem odd that the change in IPV is determined by the spatial scales of MF and TF, but the IPV advection can be calculated from the TF and MF effects without SAAC, and it is the same, which is not surprising since the conservation of IPV during SAAC was used in the algebra (IPV may not be conserved during MF and TF because of viscous and diabatic contributions). And MF and TF forced IPV changes are affected by H and L because: forced change in S by TF ~ Q*qad / Hp and of course, forced change in RV by MF ~ W*RVad ~ - Hp * W * G/f * qad /L^2 NOTICE, Ross = G * Hp^2/L^2 * S/(AV*f) Thus sqrt(Ross) = Hp/L * sqrt[(G*S)/(AV*f)] If Ross = 1, L is proportional to the internal Rossby radius of deformation for a given Hp.
128991. Patrick 027 at 14:52 PM on 19 January 2009
        Volcanoes emit more CO2 than humans
        It also occurs to me that Spencer's analysis could be capturing some aspect of the annual cycle.
128992. Patrick 027 at 12:11 PM on 19 January 2009
        Volcanoes emit more CO2 than humans
        3 and 4 in last comment - What I mean - Spencer refers to striations and spirals. Are those spirals predominantly clockwise or counterclockwise? (And does it vary by the size of the spiral? Etc...) It may be that the method for figuring out climate sensitivity that Spencer is criticizing is actually not a very good method, for perhaps some of the same reasons that Spencer's own method seems lacking. But this is just one piece of the puzzle (which might have been helpful but unnecessary? - There is a lot of other evidence out there). For example, Spencer mentions use of this method on climate models. But the most clear cut way to evaluate climate model sensitivity is to have multiple runs in response to various forcings and compare. ------------ "The curve was rejected and is now accepted by the consensus" Could you show me where it is accepted?
128993. ANTILiberal at 11:54 AM on 19 January 2009
        We're heading into an ice age
        I heard about this on the radio last month, and this would prove that we are not the cause of climate change, and that industrialization is not harmful. Unfortunately, many people are still advocating global warming since they have their money on it. This seems to be the strategy for defense of these advocates: "if any part of the earth gets warmer during the industrialized age, industrialization is to blame. If the earth gets cooler, of course, industrialization is a bad thing anyway. Heads, I win. Tails, you lose!
128994. Patrick 027 at 11:45 AM on 19 January 2009
        Volcanoes emit more CO2 than humans
        The problems I saw in Spencer's approach: 1. he was looking at climate sensitivity based on Temperature and radiative fluxes (top of atmosphere (TOA)) over rather short time periods. This is not an equilibrium climate sensitivity at all. (PS if a period of 5 years is sufficient, then why isn't 40 or 100 years of warming sufficient?) 2. conceivably there could be some net global cloud feedback, as well as the ice-albedo and and water vapor feedbacks and others, to forcing of climate from CO2, etc. Over short time periods (this is part of concern 1, actually), any water vapor feedback and other feedbacks, etc., would be limited by thermal inertia of the oceans. In addition, CO2 would generally only be a feedback over longer time periods. What is the cloud feedback to cloud forcing? 'Internal Radiative Forcing' is a feedback to some other internal effect, and will react to itself... 3. If one of the graphs could be shown in enough detail, one might judge to what extent temperature fluctuations are driving radiative fluctuations and vice-versa - obviously both happen - they must, that's the physics. 4. On that note, there can be some correlation, perhaps with some lag in time or not, between cloud radiative feedback and temperature, or temperature changes, that is not entirely due to a direct forcing of temperature by clouds OR a direct forcing of clouds by temperature. The short term variability may involve fluctuations in cloud type, amount, and distribution, and in temperature and wind, etc, that are of a different nature than that of longer term changes. 5. Spencer's description of how the IPCC, etc, estimate sensitivity is not descriptive enough for me to judge what it means. ------- FROM http://www.drroyspencer.com/research-articles/satellite-and-climate-model-evidence/ "And it appears that the reason why most climate models are instead VERY sensitive is due to the illusion of a sensitive climate system that can arise when one is not careful about the physical interpretation of how clouds operate in terms of cause and effect (forcing and feedback)." This seems to set aside any work that goes into trying to realistically model clouds based on observations of clouds and weather on smaller spatial scales (relative to global) - I think 'they' do that. " The allure of models is strong: they are clean, with well-defined equations and mathematical precision. Observations of the real climate system are dirty, incomplete, and prone to measurement error. " Well, I guess we should trust the models, then, eh Spencer? :) (I just found that particular passage to be very ironic, and not just within the context of this paper.)
128995. Steve L at 07:38 AM on 19 January 2009
        Latest satellite data on Greenland mass change
        Oh dear, I missed that Mizimi was writing about Iceland and not Greenland. Mizimi, please answer Ian's questions about where you're getting your info. Looks unreliable!
128996. Quietman at 07:19 AM on 19 January 2009
        Volcanoes emit more CO2 than humans
        Sorry, I missed something that you said. The Fairbridge curve and the Solar Jerk are two different hypotheses. The curve was rejected and is now accepted by the consensus while the solar jerk still has not been accepted. They are unrelated subjects.
128997. Patrick 027 at 09:59 AM on 18 January 2009
        Arctic sea ice melt - natural or man-made?
        CORRECTION to 408: third paragraph (the one that starts: "In contrast, for the eddy thermal fluxes that would cause a decrease in the geostrophic u," ) ... "The adiabatic MMC caused by this is in the same direction as that described by the previous paragraph." The exact opposite is true. The same point was made and implied correctly in other parts of comment 408. BUT often, the two MMCs are in the same direction, with the u'v' and v'T' effects making opposite contributions to the net change in IPV and balanced wind distributions. In particular, the vertical variation in RV advection and the horizontal curvature (Laplacian) of temperature advection (following the motion of the air) tend to have opposite effects, when advection is mainly by geostrophic winds, as described previously (comments 319 - 323). Whether the RV advection or the temperature (T) advection dominates in the IPV tendency depends on length and height scales, stability, AV and f, some other things - in a relation that is very similary to the relationships in the formula for the Rossby radius of deformation. More on that later... PS the example of an SSW in Holton, p.416, (estimated from a graph) shows (in terms of zonal averages) a warming of the polar stratosphere at the 50 mb level (PS sea level pressure averages ~ 1013 mb; 1 mb = 100 Pa = 100 Newtons/square meter), most of it in about 5 days, greater than 10 K (10 deg C, 18 deg F) north of ~ 65 deg latitude, greater than 30 K at ~ 80 deg latitude; with a reduction in the zonal wind of over 10 m/s north of ~55 deg latitude, becoming easterly north of ~61 or 62 deg latitude. Holton p.415: the warmings can be as much as 40 K. An SSW involves distortion and breakdown of the westerly circumpolar vortex in the stratosphere. Enhanced planetary (Rossby) wave propagation from the troposphere, of mainly zonal wavenumbers 1 and 2 (when a wavenumber is given without units, in this context it refers to the number of wavelengths that fit around a circle of latitude; zonal wavenumbers 1 and 2 are the longest of zonal wavelengths) is "essential" (Holton p.415) to produce an SSW.
128998. Quietman at 08:47 AM on 18 January 2009
        Volcanoes emit more CO2 than humans
        ps This is spencers site. Articles and links to peer reviewed papers. http://www.drroyspencer.com/
128999. Quietman at 08:46 AM on 18 January 2009
        Christmas cartoon on melting North Pole
        Sorry, Are we in another La Nina now?
129000. Quietman at 07:11 AM on 18 January 2009
        Volcanoes emit more CO2 than humans
        Spencers argument is specifically about sensitivity to CO2. Look under Arguments, the Pacific Decadal Oscillation (at this site). I posted a link to a draft he did that they have refused to publish. I would prefer to be wrong about all this as I much prefer a warmer world but I fear that Spencer may be right. I am sure that Fairbridge was as the last two winters have been showing. The test is 2007 through 2011. Halfway there.

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