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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 73451 to 73500:

  1. Review of Rough Winds: Extreme Weather and Climate Change by James Powell
    KR @ 128 "In other words, you searched for extreme events at other times, ignoring statistical indications and trends, in order to present possible counter examples. This is classic cherry-picking, Norman. It's (from the definition, "a kind of fallacy of selective attention"), hunting for the subset of data that supports your hypothesis and ignoring the mass of evidence that might contradict you." That is not at all what I did or described that I did. I went to the NOAA website that lists extreme weather events for given years. I selected one (without looking at the others) and posted the result in #95 to muoncounter with a link to the NOAA page I grabbed it from. I would agree with you on cherry-picking if I looked at many extreme weather reports and picked the most extreme out of the bunch. I did not do this and do not know what the other years hold in terms of extreme weather.
    Response:

    [DB] "I would agree with you on cherry-picking if I looked at many extreme weather reports and picked the most extreme out of the bunch. I did not do this and do not know what the other years hold in terms of extreme weather."

    Relying upon happenstance in the absence of known, statistically robust, methodologies is sheer folly.  So then call it raspberry/orange/apple/kiwi/squash/etc-picking.  Closing ones eyes and walking into a busy thoroughfare because one doesn't believe in extreme traffic doesn't make one's body impervious to being run over.

  2. Review of Rough Winds: Extreme Weather and Climate Change by James Powell
    KR @ 128 "* Earthquake numbers are underestimated due to better building codes. * Reporting codes (for weather only, not earthquake, a peculiar distinction) have changed to increase disaster reports." I believe this earthquake chart may show my case in point. Also please look at how ridiculous claims are about earthquake disaster number. Check out the world earthquakes for the years 1976 and 1977. Very close to the same number of earthquakes but look at the huge difference in fatalities. If disaster reports for earthquakes are relatively flatline they really do not address the actual disaster of an earthquake. That is a side point (something to consider). The big point would be to look at the fatalities around the world from earthquakes. Then look at the US fatalities. The percentage of earthquake number to fatalities is much lower in the US. I wonder why? Is my building code argument really that lame to you? What answer can you provide for this difference in fatalities to earthquake number between the US and the rest of the world? But the bigger thought here is that disasters are not a good way to determine extreme weather frequency. All I ask for is a better system, does that make me a "bad guy"? I think it would qualify for scientist. Less dependent on a shifting variable like human behavior, population increase, property values, dumb choices, etc. Earthquake data.
  3. Review of Rough Winds: Extreme Weather and Climate Change by James Powell
    KR @ 128 "I may have overstated this - what you are actually asserting is that it's impossible to prove that extreme weather has increased. That seems to be a firmly held opinion, and I believe is leading you into confirmation bias, shaping what evidence you find acceptable." I did not know that is what I was asserting. I explained what I believed would be a good way to determine if extreme weather is increasing. You create scales like hurricanes and tornadoes for other extreme weather events and then you collect the data and see if the trend is positive. This is a certain way to prove extreme weather is increasing. * Records of disasters are biased by population shifts/changes, and no actual event changes have occurred. Hence the insurance information and FEMA disaster records are inaccurate. I am not claiming insurance and FEMA disaster records are inaccurate. I am claiming disasters involve humans and property and with shifting growing population and more valuable property it will tend to distort the connection between real events. I presented a useful thought experiment to demonstrate the point. If you have the same number of extreme events a year but the population moves to areas more prone to these exteme events (such as moving into tornado alley, moving along coasts with numerous hurricane strikes, moving into flood plains with known history of flooding) and builds bigger better houses and fills them with higher cost items you can see that even if the number of extreme events stayed the same, in this scenerio disasters would increase as the extreme events would have a better chance of causing more damage and death. This is a clear case showing how disaster events do not have to correlate with actual number of extreme events. Just think it through. You can take the thought experiment either way. Here is some evidence that no visible trend exists in US disasters over a 22 year period (1988 to 2010). If you remove the extreme hurricane Katrina (which did not kill so many in itself but a faulty built levi was the problem with this one) you can see there is no significant trend in monetary or fatalites caused by extreme weather events. 22 years of weather related disasters in US. Above link from this page Link to graph above.
  4. Pielke Sr. and SkS Disagreements and Open Questions
    Dana, May I ask how transient is "transient climate response"? Because, I don't know how you ever avoid obfuscation issues with lag. Why the temp might be under the best estimate could be because, a) the best estimate is a little off, b) there are some small cooling effects being introduced as well, or c) there is a bit more lag in the system than was estimated. I'm not entirely clear on this, but it might be premature to say that (b) is the answer. Hmm, I'm wondering if the answer doesn't hinge on the outcome of the debate whether there is missing heat, possibly in the ocean depths where it is difficult to measure, or there is no missing heat, possibly because of an increase in aerosols from China and India (mostly).
  5. Climate Change Could be Expensive for Canada
    Hi Man, Nice to see a reasonable post added to the antagonistic rhetoric displayed earlier. I do not know whether the pros actually outweigh the cons as reported by Albatross in the earlier NRT report, but at least someone else is willing to acknowledge that they exist. Sphaerica seems to object to the mention of agricultural benefits in the report, (-Snip-). Discussing only the negatives, without acknowledging the positives is akin to a corporation reporting revenues only, and omitting costs. It would look quite lopsided. I am only a border Canadian (I live in Michigan), but we have experienced some of the same positives/negatives as our friends to the North.
    Moderator Response: [DB] "I do not know whether the pros actually outweigh the cons"

    Perhaps then you should actually do the background reading, as suggested, before making such seemingly authoritative statements.  Else your comments look quite lopsided.

    Inflammatory snipped.

  6. Pielke Sr. and SkS Disagreements and Open Questions
    KR, thanks for adding those. I was tunneled in on energy and forgot about the chemical changes.
  7. Pielke Sr. and SkS Disagreements and Open Questions
    Keith, Nice pickup on the distinction between contribution to radiative forcing and contribution to warming. I followed Dr. Peilke's comments to where he mentions that figure, and then to the slide that he referenced, and I'm struggling a bit with understanding his claim that, "The CO2 contribution to the radiative warming decreases to 26.5%" Granted, there are other changes that are forcings, for instance an increase in black aerosols, and if CO2 were to stay the same and they were to increase, then, percentage-wise, there could be a decrease in the relative forcing of CO2. But, CO2 has increased by ~40%, and even given the logarithmic nature of its effect, I have a hard time believing that the effect of the other constituents has increased so much as to cause a relative decrease in the effect of CO2. If that were the case, then I suspect there would be a lot more missing heat to account for. Because, if we can calculate the expected increase in warming from just CO2 at around 0.9 K, there would have to be more forced warming from other sources in order for there to be a percentage decrease in CO2's contribution. In any case, you are right, the question was, how much of the warming, and what he answered was how much of the radiative forcing, and they are not the same.
  8. Pielke Sr. and SkS Disagreements and Open Questions
    Agnostic Chris G has a point. I'll add that even without temperature changes, increasing CO2 has an effect on ocean acidification and C3/C4 plant responses - climate change as well. That said, global temperatures are a really important indicator, and I feel Dr. Pielke is inappropriately dismissing it.
  9. Pielke Sr. and SkS Disagreements and Open Questions
    Agnostic, I'll have a go at answering your question. It really isn't all about change in temperature. Rather, it is about change in energy. Changes in energy can cause phase state changes, like between water and vapor, and water and ice. Difference balance points between where energy is absorbed and where it is transferred somewhere else can affect wind patterns, and also currents. Temperature makes a nice proxy for energy levels, but climate change is more than just temperature because different energy levels change more than just temperature.
  10. Pielke Sr. and SkS Disagreements and Open Questions
    I have a problem with the assertion that …. “Based on the NRC definition, the increase in global temperature is a subset of climate change.” In my view, all aspects of climate change have one thing in common – change in temperature. How then can it be seen as anything other than the driving force rather than a sub-set of climate change?
  11. keithpickering at 09:17 AM on 1 October 2011
    Pielke Sr. and SkS Disagreements and Open Questions
    It looks to me like Pielke Sr. has simply taken the 26%-for-CO2 number from the paper of Kiehl & Trenberth 1997, which concluded that CO2 is responsible for 26% of the greenhouse effect. That's a long way from 26% of the warming, however.
  12. Modern scientists, following in Galileo’s footsteps
    38 - Tom Smerling My "instrument maker" remark was, obviously, an exaggeration to offset the exaggeration of the Galileo's 'uniqueness' myth - and I mean 'myth' in the sense of stories we develop and tell our selves to help us understand systems of thought - not 'myth' in the popular sense of fiction. I'm not saying he wasn't one of the greats - just that, in the potted histories we tell, his position is a bit exaggerated for for convenience. And to illustrate the point. "what prompted A. Einstein to dub Galileo "the father of modern physics—indeed of modern science altogether," and Stephen Hawking to state, "Galileo, perhaps more than any other single person, was responsible for the birth of modern science."" Of course, both Albert and Stephen are/where theoretical physicists; not historians of science / philosophy of science (let alone experimentalists!). Of course, knowing they're part of the story, they support and promulgate the received narrative of their disciples... Still, how often do people, correctly, point out that just because some skeptic is a science X, doesn't make him/her knowledgeable in climate modeling or what ever... Clearly the 'skeptics' comparing them selves to Galileo shows a very poor understanding of history... Still, history doesn't really repeat it's self although, as they say, it might rhyme.
  13. Climate Change Could be Expensive for Canada
    As a Canadian Lover-of-this-website, (for its attention to science) I must say I'm glad my country is getting some sks time. Canada's economy should grow as fossil fuels become more difficult to extract. This will happen with or without global warming. I imagine our water resources will become more valuable if the climate warms - also a plus financially. Blueberries can become a larger crop for as we warm etc. More tourism would also be enjoyed. But there are certainly negatives, and you will be hard pressed to find an honest economist who will defend that the status-quo fossil fuel use is financially prudent. This past decade 2000-2010, our insurance claims have more than doubled over the previous decade. http://www.canadianunderwriter.ca/news/aviva-canada-claims-data-show-increased-frequency-severity-of-water-claims-costs/1000406401/ I imagine that the latitudes that Canada inhabits will be a battleground between the arctic air and the warm air from the south as new "normals" are set and then changed again. Our precipitation should increase, and climate get weirder by the climate models I have seen. We have had some bad experiences with invasive species that should not be neglected in "cost to Canada" calculations, and we already have "climate refugees" in the far North as permafrost melts where it hasn't melted before in many many years collasping the ground beneath buildings. I look forward to a better financial future, however I am skeptical.
    Response:

    [DB] Canada was also featured prominently in this thread: Twice as much Canada, same warming climate.

  14. 2011 Sea Ice Minimum
    What an interesting thread I've been missing! Just wanted to interject some (hopefully) salient points into the dialogue. 1. As far as predictions and "tipping points", Eisenman and Wettlaufer (PNAS 2009), in their publication "Nonlinear threshold behavior during the loss of Arctic sea ice" state:
    Our analysis suggests that a sea-ice bifurcation threshold (or “tipping point”) caused by the ice–albedo feedback is not expected to occur in the transition from current perennial sea ice conditions to a seasonally ice-free Arctic Ocean, but that a bifurcation threshold associated with the sudden loss of the remaining seasonal ice cover may occur in response to further heating. These results may be interpreted by viewing the state of the Arctic Ocean as comprising a full seasonal cycle, which can include ice-covered periods as well as ice-free periods. The ice–albedo feedback promotes the existence of multiple states, allowing the possibility of abrupt transitions in the sea-ice cover as the Arctic is gradually forced to warm. Because a similar amount of solar radiation is incident at the surface during the first months to become ice free in a warming climate as during the final months to lose their ice in a further warmed climate, the ice–albedo feedback is similarly strong during both transitions. The asymmetry between these two transitions is associated with the fundamental nonlinearities of sea-ice thermodynamic effects, which make the Arctic climate more stable when sea ice is present than when the open ocean is exposed. Hence, when sea ice covers the Arctic Ocean during fewer months of the year, the state of the Arctic becomes less stable and more susceptible to destabilization by the ice–albedo feedback. In a warming climate, as discussed above, this causes irreversible threshold behavior during the potential distant loss of winter ice, but not during the more imminent possible loss of summer (September) ice.
    Emphasis added. The article also contains this graphic:
    The inclusion of nonlinear sea-ice thermodynamic effects stabilizes the model when sea ice is present during a sufficiently large fraction of the year, allowing stable seasonally ice-free solutions (red solid curves). Under a moderate warming (∆F0 = 15 Wm -2), modeled sea-ice thickness varies seasonally between 0.9 and 2.2 m. Further warming (∆F0 = 20Wm -2) causes the September ice cover to disappear, and the system undergoes a smooth transition to seasonally ice-free conditions. When the model is further warmed (∆F0 = 23Wm -2), a saddle-node bifurcation occurs, and the wintertime sea ice cover abruptly disappears in an irreversible process.
    2. Parties interested in the processes of bottom melt and the mixing layers underneath the ice would do well to look at "Mixing, heat fluxes and heat content evolution of the Arctic Ocean mixed layer" Sirevaag et al 2011 3. Another fascinating paper which I regret to not having internalized yet: "Influence of Initial Conditions and Climate Forcing on Predicting Arctic Sea Ice" by Blanchard-Wrigglesworth et al GRL 2011
    "In the model there are times when no significant area predictability exists from either initial conditions or climate forcing, whereas for volume, significant predictability is present almost continuously."
    The Death Spiral yet lives...
  15. Modern scientists, following in Galileo’s footsteps
    If you have not already done so, I highly recommend that you take a gander at Chris Mooney's "Memo to Rick Perry: Galileo Was a Liberal" posted on DeSmog Blog. To access Mooney's article, click here.
  16. Climate Change Could be Expensive for Canada
    Jonathon @9, You would be in a position to answer your own question if you read the reports. The rest of your post just argues strawmen and floats red herrings.
  17. Climate Change Could be Expensive for Canada
    Jonathan, I'm sorry, but anyone who is expecting any positives to come out of real climate change (I'm not talking about the dinky little early climate change we see now, I'm talking about where we're headed) is absolutely kidding themselves. For example, you talk about increased agricultural production. Sorry, no. This has been discussed to death, but warmer does not have to equal better. It can also mean more pests (i.e. a better world for insects, not plants, or for weeds, not useful crops). Also, plants need light. Making it warm further north won't affect the amount of daylight available, or how direct that light is. One thing that I learned that surprised me is that you can't simply move agricultural production north because of topsoil. You need topsoil, and a lot of the land further north has had the topsoil scraped clean by advancing ice sheets during glacial periods. There are other threads that discuss this. You should research them before donning those rose colored glasses.
  18. Modern scientists, following in Galileo’s footsteps
    @Tom, I think Rational Wiki's rebuttal is a more concise version of my point: 'being persecuted doesn't make you right; supporting the consensus doesn't make you wrong'. To that I'd add (with thanks to KR, above) "demonstrating the evidence to support your theory trumps both". That's what I'd say to anyone who plays the Galileo card.
  19. Climate Change Could be Expensive for Canada
    Jonathan (#7), There are fallacies in your reasoning. It's not so relevant what the current death rate is but how it changes in response to climate change. The study I linked (also cited by the report) indicates little change in mortality in winter months going forward in 3 Canadian cities. Similarly, what matters to energy costs is how they change over time, not what they currently are. Could be that heating costs are reduced more than AC costs are increased in a warming climate. It also could be that Canadian homes are built for heat efficiency, and so energy costs will be more sensitive to increased summer heating. I do think it would have been nice if they estimated changes in energy costs, but it's not clear to me which direction it would go. The report indicates that this is not meant to be the last word on the topic.
  20. Climate Change Could be Expensive for Canada
    Sorry to dribble… Obscure references deserve links, particularly on an international forum. Here’s a couple: http://www.vancouversun.com/business/Pipelines+coast+more+important+than+Keystone+HSBC/5453565/story.html http://www.marketwatch.com/story/canadian-crude-under-attack-on-two-fronts-2011-09-29
  21. Climate Change Could be Expensive for Canada
    Add to #8: And if we Yanks don't get our XL straw to suck it all up with, Canada seem all to willing to sell it to China.
  22. Pielke Sr. and SkS Disagreements and Open Questions
    Water vapor is a feedback while we're discussing forcings, so that's not the issue. I think it's mostly that Dr. Pielke thinks the black carbon forcing is underestimated, and possibly methane as well. I discussed this in 'CO2 contribution' section.
  23. Modern scientists, following in Galileo’s footsteps
    Question for all: What should be the #1 point to make in an SkS "basic" rebuttal (this rebuttal is "intermediate")? i.e. Given just one shot, what is single succinct " killer" argument you would use to puncture the Galileo Gambit? My original draft "brief rebuttal" was simply this: "The comparison is exactly backwards. Modern scientists follow the evidence-based scientific method that Galileo pioneered. Skeptics who oppose scientific findings that threaten their world view are far closer to Galileo’s belief-based critics in the Catholic Church." Can we do better, in light of the comments above? Along these lines, Rational Wiki has a concise rebuttal to the "Galileo Gambit" (their term). The generic form is: “They made fun of Galileo, and he was right. They make fun of me, therefore I am right." The essence of their rebuttal: "There is no necessary link between being perceived as wrong and actually being correct; usually if people perceive you to be wrong, you are wrong. . . [nothwithstanding] the selective reporting of cases where people who were persecuted or ostracized for beliefs and ideas that later turned out to be valid." It's worth checking out, at http://rationalwiki.org/wiki/Galileo_gambit. It concludes with that delicious, but perhaps unuseful, Carl Sagan quote about Columbus, Fulton, the Wright Brothers.....and Bozo the Clown!
  24. Climate Change Could be Expensive for Canada
    Canada is in an interesting position. Not only do they consume carbon based fuel at a per capita rate comparable to the US, but they also sit on one of the largest resource of very carbon intensive oil. Short of producing oil from coal it is tough to beat tar sands for carbon intensity when it comes to mile driven.
  25. Climate Change Could be Expensive for Canada
    Albatross, If the earlier NRT report concluded that the pros outweighed the cons, why should we focus on this new report where the pros are omitted, and only the cons are listed? Even though Canada is better adapted to cold weather than many other counties, the death rate is still highest in the winter months. http://www.cmaj.ca/content/181/8/484/F1.expansion.html By the way, air conditioning costs in Canada cannot compare to heating costs.
    Moderator Response: [John Hartz] For better or for worse, SkS did not post articles on the first three reports produced by NRT when they were released. We encourage you and all other readers to peruse the entire set of reports. I will provide direct links to each of the first three reports as an addendum to the above article.
  26. Pielke Sr. and SkS Disagreements and Open Questions
    Forgot to finish that line of thought: The what-about-the-paleoclimate response to low sensitivity estimates has almost become a meme on the AGW side, but then, I've been seeing it for years, and I have yet to see a comprehensive response. IIRCR, Lindzen made an attempt, but it fell short of being globally applicable.
  27. Pielke Sr. and SkS Disagreements and Open Questions
    Angliss #1, IDK, but it is possible, I can't speak for any contributors to the exchange. In any case, water does not spontaneously decide to become vapor, or delay precipitating once thresholds are reached, and there is already plenty of it exposed to air; therefore, it is not a primary driver. It can only respond to and enhance warming or cooling around it. So, if Pielke is comparing water vapor with CO2, he is comparing a feedback with a forcing, and the discussion has been around primary forcings. CO2 can also be a feedback because a temperature change can alter the carbon cycle, but in this case we know we have added lots of gigatons to the biosphere; so, we know we have created a causative agent, and we can only hope that our cause does not trigger a strong feedback of itself. Dana, thanks for completing the flip-side of what you came to an agreement on. It's kind of anti-climactic for me, but not completing it would have been a gaping hole in the series. It strikes me that many in the denier camp cling to the proposition that AGW is only based on models because the models are complicated and never 100% right; so, they are easy to argue against. Whereas, the paleoclimate record is simple to understand, and it is hard to argue against the idea that, this is what the earth has done in the past, we can expect it to do something similar now.
  28. Dikran Marsupial at 04:11 AM on 1 October 2011
    2011 Sea Ice Minimum
    Bernard J. Here are some sea ice volume projections, they look a bit pessimistic to me, usual caveats about this being a purely statistical projection apply, YMMV. This gives the general shape of the projection: Focussing in on the near future: The periodic covariance function looks like a neat way to model the seasonality. prediction for 2012 = 4.342434 (+/- 2.071584) 10^3km^3 prediction for 2013 = 3.306950 (+/- 2.227936) 10^3km^3 prediction for 2014 = 2.211567 (+/- 2.426253) 10^3km^3
  29. Understanding climate denial
    cRR: The ability to change your stance like that is the essence of skepticism. Above all, we must remain skeptical of ourselves :) Stephen: You're right. The anti-CAGW/right-wing blogosphere is not representative of typical 'denialism'. In reality most people on both sides aren't well informed and will tend to the default position of whichever political team they're on. This puts undue influence in the hands of political leaders. The politics should be about addressing the problem, not assessing whether there is one (I thought we'd set up an independent international body to do that). The point you made about being non-threatening is very important. Derision and accusations incline people to commit further to their opposing view, rather than relax and listen to yours.
  30. Pielke Sr. and SkS Disagreements and Open Questions
    One quick comment (still digesting this) - SkS and Pielke Sr may be talking past each other on the CO2 thing. I suspect he's thinking of CO2 vs. water vapor, while you're not.
  31. 2011 Sea Ice Minimum
    40, Tom, 43, Dikran, I believe, however, that the "lower angle of incidence" theory presumes that incoming sunlight is a major factor in local warming/melt. I thought that it's been determined that the water temperature and not the sunlight itself was the main factor. Admittedly, the increase in local warming due to more exposed water due to more ice melt will still be lower (due to the lower angle of incidence), but if the main temperature of the water comes from heat being transported in from outside of the Arctic, then I would think that would low angle of incidence would be a minor factor. The bigger factor, in the end (I believe) will be flat out warmer water temperatures. Ten years from now, with the water that much warmer, everything will melt faster and more thoroughly, from start to finish. Eventually it will be so warm that it just overwhelms whatever ice is there. For that reason, I think that the end will come surprisingly quickly. [On the flip side, I do think the complete disappearance of the sun, dropping air temperatures to the point where things start to refreeze, is a major factor, and the fact is that the melt season is much shorter at the actual pole, so it may be a long time before the seas are warm enough to melt everything there before the sun sets.]
  32. Understanding climate denial
    One thing we've not considered is the role of the sociopath in spreading denial. People with sociopathic tendencies apparently make up 4% of the population. I can't help think sometimes that some of the most vociferous of those in climate change denial would come out very clearly in this questionnaire as sociopaths. I'd mention one famous touring 'sceptic' by name but I guess he'd threaten to sue me. And if that doesn't give you a clue to whom I refer, I don't know what would!
  33. Modern scientists, following in Galileo’s footsteps
    John R#40: "Being persecuted does not make you right," Let's not give those in denial a pass on that. Persecution? Really? Giordano Bruno was persecuted. Having to publish a paper (of dubious value) in a minor journal rather than in Nature doesn't come close. "any more than agreeing with the majority somehow makes you wrong." And yet you often hear that on the denial blogs. To agree with the majority position is said to have 'drunk the Kool-aid' or to be somehow incapable of independent thought. As if it is impossible to independently review the evidence and conclude that the majority opinion is correct. Example: The FT is drinking climate KoolAid -- by none other than our friend RPJr.
  34. Modern scientists, following in Galileo’s footsteps
    To be the "next Galileo", it is not sufficient that you be a maverick, that your theories are contradictory to the consensus, that you are laughed at. You must also be correct. That's a rather higher standard.
  35. OA not OK part 20: SUMMARY 2/2
    My apologies, Bernard J. - in my previous post I was mistakenly responding to the "acidification" portion, not the (quite correct) variation of neutral point. More caffeine needed, I believe...
  36. 2011 Sea Ice Minimum
    "Whether or not melting ice follows a Gomperts path, I suspect that it will follow one of the asymmetric sigmoids..."
    ...for the sort of reason that Dikran Marsupial mentions in the first paragraph of #38.
  37. OA not OK part 20: SUMMARY 2/2
    The last time I ran into the semantic issues with "acidification", I simply noted that: If you stand at the South Pole, then walk 100 meters in any direction, you are still in the Southern hemisphere. But, you have indisputably moved 'northward'. And 'acidification' is the term used for a chemical mixture moving towards acidity.
  38. 2011 Sea Ice Minimum
    Logistic curves are nice and easy, but they're symmetrical about the point of inflection, which is often quite an artifical assumption about natural processes. Of course, this is not to say that the shape of a Gompertz is not itself an artifical fit to certain sets of data (usually it is), but in various ecological contexts at least I've found Gompertz nearly always seems to better describe the nature of trajectories than do logistics, von B's, or other of the stable of sigmoids. Whether or not melting ice follows a Gomperts path, I suspect that it will follow one of the asymmetric sigmoids...
  39. Modern scientists, following in Galileo’s footsteps
    Tom Smerling @38, while I cannot speak for Einstein or Hawking, it is absolutely true that Galileo invented modern science with his detailed observations of bodies in motion. That, far more than his astronomical observations and writings marked a break with past practice and dependence on authority rather than observation as arbiter of knowledge.
  40. Modern scientists, following in Galileo’s footsteps
    Tom, les, The 'Galileo was persecuted, but right' meme should be paired with the 'just because it's the consensus doesn't make it correct' meme. They both spring from the same cherry-picking of history and both are very popular with those in denial. Being persecuted does not make you right, any more than agreeing with the majority somehow makes you wrong. And, by definition, once you've been proved right and everyone suddenly agrees with you, you're in the consensus; and then it's those that don't agree with the new consensus that suddenly become the mavericks. What makes someone either a 'Galileo' or a part of the consensus, is just where you choose to draw a line for the start and end dates. The arbitrary nature of which shows up exactly why these memes are so utterly flawed! Galileo was Galileo and trying to make serious comparisons in support of any take on climate science is just plain bonkers.
  41. Philippe Chantreau at 02:41 AM on 1 October 2011
    Modern scientists, following in Galileo’s footsteps
    Tom makes an excellent point. Someone, maverick or not, may very well be right about a subject and at odd with accepted ideas on that subject. However, it takes more than the correct insight to convince others, it takes sufficient evidence. Science is not a game of "I told you so 20 years ago." If the evidence supports accepted ideas better than new ones, they will remain in place until more evidence is acquired. It is possible that some true skeptics are right about the role of CO2 in climate, but they have so far furnished no evidence near sufficient enough to overturn the current, painstakingly acquired model of Earth climate.
  42. Dikran Marsupial at 02:38 AM on 1 October 2011
    2011 Sea Ice Minimum
    Tom Curtis Thanks for that, being wrong is always an effective way of learning! The models in the Stroeve et al. paper (thanks muon) have a sigmoidal shape, which is strong support for that kind of model.
  43. 2011 Sea Ice Minimum
    No shame for an out of work philosopher to be scooped by Bob Grumbine on Arctic ice.
  44. Stephen Baines at 02:35 AM on 1 October 2011
    Understanding climate denial
    Tristan, I agree that it will be hard to turn any of the big names. Afterall, it is their uniquely active intransigence that has made them "big names" in the first place and which has put them in the position where reversal will lead to public humiliation. If they hadn't sold themselves down the river intellectually, they would have been convinced by the evidence years ago. But for the same reason I think we should be careful not to paint too broad a canvass from their unusual example. That way leads to nihilism. In my experience, many people who "deny" climate change do so on a much more passive/indirect basis. (Note, I do not consider people who post on internet blogs a random sample of these people!) They are either going along with others they relate too, against others they don't relate to, or they are challenged by the idea that the effect of humans could compare to the power of nature. With all the noise surrounding communication about climate science, those indirect associations take over. But I do not believe they are not as committed personally to that position as the public faces of denial. They will listen to evidence when presented by a non-threatening source. In every major environmental debate on which the science spoke clearly, the science has won in the end, despite enormous efforts to derail it. That is not a call to complacency - it took effort. But you have to think that most people can be convinced by the evidence, else we might as well just give up and colonize Mars.
  45. 2011 Sea Ice Minimum
    Tom C: Bob Grumbine scooped you with a logistic curve fit: By my estimation method, there's about a 50% chance (54%) that 2035 or some year before that will show zero ice extent for September. It's only 6% that we'd see zero ice in 2029 (or before). And rises to 96% that we'll see zero ice (for the month) in 2042 or before. The 'or before' is important. Similar shaped graphics from model runs in Stroeve et al 2007, although the earliest ice free point in that paper was 2050.
  46. 2011 Sea Ice Minimum
    Dikran @38, as the sea ice area decreases, its limit comes closer to the pole. Consequently the angle of the incoming sunlight to the horizon decreases, and less energy per square meter is recieved. Hence a lower ice albedo feedback. As the minimum sea ice extent is in September when the sun is already low, that may well be enough to justify a Gompertz model. Not that I would in anyway dispute Larry Hamilton's final sentence.
  47. 2011 Sea Ice Minimum
    TomCurtis. Dang. You just took the wind from my sails. Being an ecologist and all, Gompertz is one of my favourite sigmoids. I was about to plug the data in, and whaddaya know, I refresh and discover that you've pipped me! Pretty cool trajectory though...
  48. Dikran Marsupial at 02:05 AM on 1 October 2011
    2011 Sea Ice Minimum
    Tom Curtis, the Gompertz model, that takes me back a bit! Is there any reason to assume that the ice loss will slow as it reaches zero rather than speed up? I would have thought that it would continue accelerating due to the albedo feedback thing. It would be nice to use a method that handles the fact you can't have a negative extent properly (in the credible/confidence interval as well as in the projection). It might be a nice application for Beta regression (where the Gaussian noise assumption is replaced with a Beta distribution with the lower limit at zero and the upper limit learned from the data (or set to the surface area of the globe). Shame the GPML toolbox doesn't support it (yet).
  49. Understanding climate denial
    Very well, Tristan, I will confess. I was certain of GW by the year 1989. And until 2004 I thought it had to be the sun. In the end I got convinced by the facts I'm pushing forward nowadays like someone who quit smoking attacks everything and all in sight to with tobacco :) What have I gained? Actually some insight into denialism, particularly AGW-denialism. But a look over this thread will give same insight :)
  50. OA not OK part 20: SUMMARY 2/2
    Harking back to Part 4 of the series, it's instructive, if apparently semantic, to note that pH 7 is not actually often the point of "neutrality", in terms of hydronium and OH- equivalence. Further, the pH of "neutrality" is temperature-dependent, and in the 'real world' it can wander half a pH unit or more from 7. As I said, it's largely semantic, but when arguing with acidification deniers it can be quite pertinent...

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