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Comments 83001 to 83050:

83001. Dikran Marsupial at 05:28 AM on 11 June 2011
       There's no room for a climate of denial
       Eric the Red wrote: "Maybe, but how many natural disasters can you name from 1998?" hardly any Eric, I think you will find that is very much the point Tom was making.
83002. John Hartz at 05:20 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Perhaps these are "dumb" questions, but nontheless... Because the enhanced greenhouse effect is all about the transfer of heat both within and between the various components of the Earth's climate system, why is only one metric, i.e., annual average mean global temperature of the troposphere" being used to define "Climate Sensitivity"? Doesn't this single metric mask all kinds of other things that are happening within and between the other components of the climate system?
83003. chris at 05:19 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Eric the Red at 04:36 AM on 11 June, 2011 Really Eric? Veizer publishes a paper in Nature with a reinterpretation of his original sea surface temperature data, that negates the possibility that the tentative Shaviv/Veizer hypothesis could be correct when considered through the Paleozoic period...... ....and now we're supposed to believe what someone says on a blog about a conversation he had with Veizer that the latter doesn't actually believe the stuff he published in the Nature paper. No thanks Eric...I'm sticking to the science. Science is about evidence and the evidence simply doesn't support the tentative hypothesis of Veizer and Shaviv. Veizer's own data pretty much scuppers it. "do not be swayed by misinformation". Brilliant Eric! In your eyes Veizer's own work constitutes both the information and the misinformation on this topic. Truly anything and everything can be twisted into a misrepresenters "argument"!
83004. garethman at 05:19 AM on 11 June 2011
       Impacts of a melting cryosphere – ice loss around the world
       Albatross A new study out documenting the loss of snow pack in the northern Rockies......... Over the past millennium, late-20th-century snowpack reductions are almost unprecedented in magnitude across the northern Rocky Mountains, and in their north-south synchrony across the cordillera. Both the snowpack declines and their synchrony result from unparalleled springtime warming due to positive reinforcement of the anthropogenic warming by decadal variability. Garethman Thanks for that, looks interesting, unfortunately it is behind a paywall so I could not look at the article. If you have read it I would be interested in the tree rings. Were these aged in terms of Millennia in being used to compare with contemporary tree rings, in other words, were these trees a thousand years old? or were the current tree rings compared to snowfall data from other sources?
       Response:

       [DB] Try here.

       Poking under rocks sometimes yields useful results.  ;)

83005. garethman at 05:12 AM on 11 June 2011
       Impacts of a melting cryosphere – ice loss around the world
       Hi Dhogaza, I think your more detailed chart shows essentially the same thing? You are correct in that the loss of sea ice has remained constant, but logically, if it has stabilised at a lower level that goes without saying? Though as I have previously mentioned I strongly suspect the reduction will again start in the near future. I happy to be proved wrong by the way! I’m not sure what the “nice try" refers to? Rugby perhaps? Are we in a competition? I also personally don’t think these charts are “lame”, they are all useful. Some focus in some areas, some in others. But to get the overall picture it’s important to look at as many as possible and not ignore those you don’t like, which is why I appreciate seeing yours or any other useful indicators you may be so kind as to direct me to.
83006. Eric the Red at 04:56 AM on 11 June 2011
       There's no room for a climate of denial
       Fair enough. However, one year does not a trend make. http://www.ncdc.noaa.gov/img/climate/research/tornado/tornadotrend.jpg Yes, this year has been unusual. As of Jun 1, we have witnessed 75 violent tornadoes (EF3 or greater), that is the third highest since 1950. With the rest of the summer remaining, we will very likely pass 1965 inot the number 2 spot, but may not break 1974's total. Was 1974 an unusual year? Apparently, we witnessed a similar La Nina occurance that year. If we finish near or above 1974, I would still say it has been an unusual year, but not rare. It has also been very cold and snowy winter, but does that mean we are headed for colder temperatures in the future?
83007. garethman at 04:46 AM on 11 June 2011
       Geologists and climate change denial
       Chill out folks! I’m not casting doubt on climate change, though for some reason this is continually read into my posts. I am interested in the human reactions to the science, the depth and breadth of emotion. It’s a painful subject for some, but fascinating all the same. Incidentally anyone who does not believe young people have more radical ideas than older people and say things they later takes a differing view on are probably in denial with regard to human behaviour and should probably go and visit a University campus to see such dynamics in action. http://www.climatecamp.org.uk/ The same with climate camp. I have camped in the same field with these guys for weeks at a time. They are enthusiastic and radical, but objective? maybe not, but it’s reassuring to see young people still have heart and are motivated to try and change the world for the better. They will be at Glastonbury again this year, if you are lucky enough to get a ticket, go and visit them, I’m sure they would rustle up a cup of tea and inspire you. What I do wonder judging by reactions to my posts is whether a lot of the odd anger expressed at posters who give contrary views or those who question evidence is misdirected. A common feature of human behaviour is that people will express anger at a subject unrelated to the cause of their anger, because it is unacceptable to express anger at the real thing. I see Right wing individuals railing at everything from immigration to climate change, when on an individual basis they are probably upset at their lack of success in life, or their family dynamics. Whenever you see an "over the top” reaction to an innocuous situation or post you can be fairly sure that it is anger expressed in an inappropriate direction. I think it’s also a mistake to call belief in science “blind faith” I have not seen any sign on this site that supports such an idea, or indeed that evidence is suppressed, and lets face it, the evidence for a warming climate is pretty conclusive. So it’s not blind faith, it’s not a religion, but our beliefs in the science and what we do about is are very much coloured by who we are. Perhaps the profession of forensic mental health are another group who are just an awkward bunch when it comes to climate change?
83008. Eric the Red at 04:36 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       For those who think that Veizer has changed his position, you might want to read this: http://jennifermarohasy.com/blog/2007/09/new-nature-paper-jan-veizer-contradicts-his-own-results/ More recent statements by Veizer seems to show that he is standing by his original conclusions, and the merits of his original paper. Do not be swayed by misinformation. Actually, I do not see where I have been shown to be wrong, although I am open-minded enough to look back. Many people have told me that I am "in denial" recently to entertain the thought that climate sensitivity could be closer to 2 than 3. That number is not unreasonable, and does not contradict the science. It does not fall beyond any reported likely range, and in some cases is the most likely value. I have seen people applaud those who state that the climate sensitivity is 6 or above, yet that is above most likely ranges.
83009. dhogaza at 04:22 AM on 11 June 2011
       There's no room for a climate of denial
       "Maybe, but how many natural disasters can you name from 1998? That is only 13 years ago, and occurrances do not come to my mind rapidly. Yes, I can remember the earthquakes from the past few years, the tsunami in Indonesia, and hurricane Katrina. However, before that, everything becomes a little bit fuzzier." Then one has to do actual research before dismissing this year as being not unusual, and to dismiss it in such a way *without* doing such research is simply denialism. Especially when scientists are telling us that this was by far the most extreme tornado April in history, that we're seeing 100 year floods, etc etc etc. There have been a large number of extremely rare events in the last year, and basic probability theory tells us that the combination of a large number of low-probability events has a far lower probability. So unless you can point to evidence that these events aren't actually rare (Joplin isn't the point, it's the incredible level of tornado activity of which Joplin and Tuscaloosa were part of that's the point, so "one tornado in 1954" is not a relevant comparison), I at least will run with the fact that the combination of low-probability events we're seeing is extraordinarily improbable, and very possibly unique in recorded history.
83010. Eric the Red at 04:16 AM on 11 June 2011
       There's no room for a climate of denial
       Dikran, Maybe, but how many natural disasters can you name from 1998? That is only 13 years ago, and occurrances do not come to my mind rapidly. Yes, I can remember the earthquakes from the past few years, the tsunami in Indonesia, and hurricane Katrina. However, before that, everything becomes a little bit fuzzier. I can remember the names of major hurricanes and areas that were hit by floods, earthquakes, and other disasters, but I cannot tell you when they occurred. In fact, had he picked any other year in the decade of the 50s, I probably could not identify a particular disaster. The "top of your head" only works well for recent memory, or for those events that yield a lasting impression on an individual (I am sure all the residents of New Orleans will remember the year that Katrina hit, long past the time that the rest of us forget). Off the top of your head, name a disaster from 2007.
83011. dhogaza at 03:40 AM on 11 June 2011
       Geologists and climate change denial
       "Touble is, garethman, we're a wee bit short on evidence that casts any significant doubt " Obviously, that's because "Any contrary evidence should be suppressed" (snort). This is blind faith at its worst ... there must be contrary evidence and since we're not seeing it, obviously it's suppressed. The possibility that there's no contrary evidence is not a possibility.
83012. Albatross at 03:36 AM on 11 June 2011
       Impacts of a melting cryosphere – ice loss around the world
       A new study out documenting the loss of snow pack in the northern Rockies by Pederson et al. (2011): "In western North America, snowpack has declined in recent decades, and further losses are projected through the 21st century. Here, we evaluate the uniqueness of recent declines using snowpack reconstructions from 66 tree-ring chronologies in key runoff-generating areas of the Colorado, Columbia, and Missouri River drainages. Over the past millennium, late-20th-century snowpack reductions are almost unprecedented in magnitude across the northern Rocky Mountains, and in their north-south synchrony across the cordillera. Both the snowpack declines and their synchrony result from unparalleled springtime warming due to positive reinforcement of the anthropogenic warming by decadal variability. The increasing role of warming on large-scale snowpack variability and trends foreshadows fundamental impacts on streamflow and water supplies across the western United States." More here.
83013. skywatcher at 03:25 AM on 11 June 2011
       Geologists and climate change denial
       Touble is, garethman, we're a wee bit short on evidence that casts any significant doubt on the prevailing theory of climate. In fact most evidence emerging tends to paint a picture of effects happening more rapidly than previously thought (e.g. Arctic ice melt). I'm rapidly getting to a certain age, and I enjoy a good steak, but I see the scientific rationale behind cutting carbon emissions a.s.a.p. very clearly indeed. There is no (sensible) two sides to the science - if there are sides, it's either that climate disruption, already arriving at a doorstep near you, is bad or it's very bad, take your pick...
83014. Albatross at 03:17 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Eric_red, To be clear. Do you a) Support Christy's blatant misinformation and attempts to mislead, b) Do you recognize that his arguments are self-contradictory, c) Do you agree that his claims highlighted in the body post are not supported by the overwhelming body of scientific research and evidence?, d) Do you understand that the "we" he refers to actually means a few individuals? It blows my mind that people doggedly and uncritically defend Christy's lamentable actions, and choose to try and fabricate debate and doubt. You have been shown to be wrong numerous time son this thread...yet steadfastly refuse to change your position in the view of the evidence presented to you. In contrast, scientists like Veizer are open-minded enough to change their position in light of new evidence-- as they should. Give it up already...or are you in denial like Christy?
83015. JMurphy at 03:02 AM on 11 June 2011
       Geologists and climate change denial
       garethman wrote : "It has been my observation of young people in Climate camp etc, that they are much more radical in their beliefs, in fact to the extent that they occasionally do not believe evidence should ever be used to prove or cast doubt on Climate change, we should just believe. Any contrary evidence should be suppressed, cars should be banned and veganism imposed by law. You get the picture" Picture ? More like a fantasy story created to try to claim that there is a hidden and evil left-wing Stalinist/Leninist/whateverotherLeftist conspiracy comprising tyrannical lefties (did I mention the Lefties ?) who want to drag us all back to caves, where we can eat grass and dirt on pain of death. Get a grip.
83016. dhogaza at 02:55 AM on 11 June 2011
       Impacts of a melting cryosphere – ice loss around the world
       Of course, garethman, there's this informative and easier to read graph from cryosphere today, which shows their area data is totally consistent with the extent data from NSIDC: That's one hell of a flattening off we're seeing there, dude. Of course this doesn't show the linear regression but the summer (green) line in particular shows clearly that the area minimum for each of the last four years lies well below the linear trend, just as it does for NSIDC, and I'm certain that analysis done on this data would show an accelerating trend, just as it does for NSIDC extent data. Maybe not such a nice try, garethman, it was more lame than I first thought given the wide variety of data available at cryosphere today.
83017. dhogaza at 02:50 AM on 11 June 2011
       Impacts of a melting cryosphere – ice loss around the world
       garethman:

       We must accept that this chart is just propaganda and there is in fact no stabilisation of ice at a substantially lower level than average.

       It's not consistent with your point as the september area minimums there are totally consistent with the NSIDC extent graph I showed above. You really need a graph like the Hamilton posted above by DB that shows month-to-month comparisons as it's almost impossible to do month-to-month comparisons on the cryosphere today graph you're showing. The fault isn't with cryosphere today, the fault is with your eyeballs, and possibly the fact that you're unaware that variability at maximum and during the early melt season is much smaller than the september minimum in the first place due to geographical constraints (in much of the arctic, freeze-up is right up to the continental shores and of course it's impossible for further sea water to freeze afterwards because continents are made of land, not water). There's a reason why researchers and amateurs alike focus on the september minimum, when geographical boundaries play a minimal role in the extent and area of sea ice. Nice try, though.
83018. Dikran Marsupial at 02:46 AM on 11 June 2011
       There's no room for a climate of denial
       Eric the Red Tom said "of the top of your head list the natural disasters of 1954" (emphasis mine). If you can only remember the one tornado, then then your answer is not very complete and you have illustrated Tom's point quite neatly.
83019. garethman at 02:44 AM on 11 June 2011
       Geologists and climate change denial
       DSL Garethman, I have to take exception at your use of "alarmist." You imply that "alarmist" and "denialist" are binary opposites. That's clearly not true. You also fail to define "alarmist." Can you point out any poster on this site who you would consider to be an "alarmist"? And could you point out any climate scientist who you consider to be an "alarmist”? Garethman. Hi DSL, I have this idea that human beings cover a range of beliefs and emotions. Therefore, logically there are alarmists if if we recognise there are any other type of personality. If you are happy to see denialists in the post, you must ( or hopefully!) also have the understanding that terms are relevant and subjective and if you are OK with using them, I imagine you are happy to extend that right to others.. My main point, to return to the discussion point was that the previous poster had correlated “denilaism” with Geologists of a certain age. It has been my observation of young people in Climate camp etc, that they are much more radical in their beliefs, in fact to the extent that they occasionally do not believe evidence should ever be used to prove or cast doubt on Climate change, we should just believe. Any contrary evidence should be suppressed, cars should be banned and veganism imposed by law. You get the picture This is healthy. Don’t panic or be alarmed. Young people go through this phase, it’s part of their development. Old duffers like myself tend to take more persuasion to move from our life long beliefs. Hopefully we all get there eventually and we all believe we must do something constructive to stop the damage being inflicted on our environment by ourselves. As long as we are not too “holier than thou” It’s a pretty broad church. By the way, I don’t think alarmists are on the opposite pole from revisionists , But I do think they are on the same continuum from complete and utter obsessive adherents tolerating no questions or doubts, to complete doubters who do not think in a logical or evidence based manner and are not really connected to the world as we know it. You are also right, in I have not seen any of them on this wise site, but if they are human, trust me, they are out there. Maybe someone could propose a continuum correlating professions to their place on the line? Such pigeon holing or reductionist concepts would provide at least entertainment if lacking methodology or illumination.
83020. chris at 02:44 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Eric the Red at 02:29 AM on 11 June, 2011 Come on Eric, you've just been shown here and here that the evidence doesn't support that tentative hypothesis of Veizer and Shaviv. Veizer himself has reinterpreted the temperature part of the apparent correlation in the paper you cite and reinterpreted it. Veizer now considers that the temperature correlates with atmospheric [CO2] at least throught the Paleozoic part of the Phanerozoic. It's pretty desperate to base interpretations on an old paper that has been shown subsequently to have little scientiic merit, and which (at least one of) the authors now consider to be incorrect!
83021. Eric the Red at 02:31 AM on 11 June 2011
       There's no room for a climate of denial
       Tom, Those of us who grew up in Michigan are well aware of the devasting Flint tornado of 1954 to which the recent Joplon tornado is compared.
83022. Eric the Red at 02:29 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Spaerica, Fine, this should satisfy both your requests. http://www.juniata.edu/projects/oceans/GL111/celestialdriverofclimate.pdf
83023. chris at 02:25 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Re the top article, Hansen's interpretation that climate sensitivity might be amplified (as much as doubled) due to very slow feedbacks, especially associated with slow ice sheet responses in glacial periods (we're in a glacial period now), is supported by other recent analysis of greenhouse gas/temperature responses from the deep past: J. Park and D. L. Royer (2011) Geologic constraints on the glacial amplification of Phanerozoic climate sensitivity American Journal of Science, 311, 1-26 abstract M. Pagani, Z. Liu, J. LaRiviere & A. C. Ravelo (2010) High Earth-system climate sensitivity determined from Pliocene carbon dioxide concentrations Nature Geoscience 3, 27 – 30 abstract D. J. Lunt, A. M. Haywood, G. A. Schmidt, U. Salzmann, P. J. Valdes & H. J. Dowsett (2010) Earth system sensitivity inferred from Pliocene modelling and data Nature Geoscience 3, 60 - 64 abstract
83024. Albatross at 02:24 AM on 11 June 2011
       Climate Consensus on a T-shirt
       DSL @25, I share your concerns; the Galileo movement will be up in arms ;) Hopefully this will be one of a series of T-shirts that portray/reflect the many independent lines of evidence that corroborate the theory of AGW.
83025. Alexandre at 02:24 AM on 11 June 2011
       Geologists and climate change denial
       CoalGeologist at 08:19 AM on 10 June, 2011 Very interesting description. Looks plausible. About the "left-wing conspiracy" bit: I've come across many different versions of that argument. - an imperialist conspiracy to keep poor countries poor - a Thatcher conspiracy to harm labor rights (don't ask me to explain...) - an Al Gore conspiracy to raise taxes (I wonder how the Gore family managed to co-opt Tyndall back then. Very long term goals!) - a developing country plot to harm American and European economies
83026. garethman at 02:12 AM on 11 June 2011
       Impacts of a melting cryosphere – ice loss around the world
       Dhgoza It's almost as though garethman isn't aware that the three years following 2007 are *all* lower in minimum extent than any other year in the satellite record, and that two of the three were well below the long-term trend, and the third right on the trend, isn't it? Aplogies Dhgoza, I was led astray by that well known denialist site Cryosphere today. Have a look at the sort of information they are brazenly publishing to lead all good men astray and lead to the sort of post which you have quite rightly criticised. We must accept that this chart is just propaganda and there is in fact no stabilisation of ice at a substantially lower level than average. http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png
83027. Tom Curtis at 02:08 AM on 11 June 2011
       The Critical Decade - Part 3: Implications for Emissions Reductions
       One thing that perplexes me about the second diagram is the elevated end point for the 2011 start. By eye, each curve has the same area underneath it. That means each strategy uses the full permissible Carbon budget by 2050, but that in turn will mean the early start/ slower reduction approach will need to cease all remaining production instantly in 2050. Presumably a better approach would to be to have slightly higher initial reductions and to reach zero emissions some time after 2050. In that case the rate of reduction for a 2011 start will be higher than 3.7%, but still less than 5.3%.
83028. Tom Curtis at 01:52 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       chris @56, thank you for the link. I was not previously aware of that paper, which is interesting. Sphaerica @54, I went through the rounds on his material some time last year. Luckily for me some of it stuck. Dikran Marsupial, thanks.
83029. Alexandre at 01:51 AM on 11 June 2011
       The Critical Decade - Part 3: Implications for Emissions Reductions
       Important data, in a form that is easy to communicate. Great post, Dana.
83030. Eric the Red at 01:46 AM on 11 June 2011
       Climate Consensus on a T-shirt
       Tom, Detroit, I think the change from global warming to climate change just caused confusion. Using global climate disruption will add even more fuel to the fire. Out of habit, I have stuck with global warming, but see people using the terms interchangeably. As far as the shirts and mugs go, I dislike them all. Mainly because I am not a big fan of using the Doran survey.
83031. Bob Lacatena at 01:43 AM on 11 June 2011
       Climate Consensus on a T-shirt
       Consider this (although maybe it still could be a little darker, or more saturated, on the lettering):
83032. KR at 01:36 AM on 11 June 2011
       Climate sensitivity is low
       MajorKoko - Feedbacks are amplifications (positive) or dampenings (negative) of a forcing change. So they're related to changes in T, not T itself. That said, there are definitely phase changes (melt of clathrates, lack of summer ice in the Arctic, etc.) where feedback levels can be expected to change. As to the original statement: "basically if there is some large negative feedback which makes the sensitivity too low, it would have prevented the planet from transitioning from ice ages to interglacial periods" The Milankovitch cycle forcing change between ice age and interglacial is estimated to be on the order of 3.4 W/m^2, for a direct forcing change of ~1C. Global temperature changes for those cycles, however, are on on the order of 5-6C or so. So a short term sensitivity of ~3C for a doubling of CO2 (3.7 W/m^2) with additional long term feedbacks (ice melt, vegetative changes, CO2 temperature/solubility changes from deep ocean, etc) matches the feedback amplification seen in the ice age cycle.
83033. Bob Lacatena at 01:35 AM on 11 June 2011
       Climate Consensus on a T-shirt
       I think the second is more effective because it puts the visual emphasis (many people are visual) on the relative quantities, and the words are there for clarification. The first would be okay, if the figures in the back popped more, maybe by using a lighter shade for the words (or darker shades for the bodies), or by using outlines instead of solid coloring for the words.
83034. chris at 01:34 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Eric the Red at 21:58 PM on 10 June, 2011 Eric, remeber that Veizer himself has reinterpreted the sea surface data you cite and concludes that his temperature reconstruction now indicates a coupling to CO2 concentrations, at least throughout the Paleozoic: R. E. Came, J. M. Eiler, Ján Veizer, K. Azmy, U. Brand & C. R. Weidman (2007) Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era Nature 449, 198-201
83035. Bob Lacatena at 01:32 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       52, Eric the Red, You response sounds rather dismissive, as if you want to put all of your emphasis Viezer, and see no reason to be skeptical about it. This thread is about climate sensitivity. We're discussing climate sensitivity. Viezer, Royer, Shaviv, etc. are all about climate sensitivity. So suddenly someone doesn't like the idea of discussing the topic? Is it only fun to wander off topic, and bring up things that belong on other threads? WTF...
83036. Bob Lacatena at 01:30 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       51, Tom, Excellent work (did it take much, or did you know this off the top of your head?), and once again you've demonstrated the need for a database which makes it easy to realize which papers, while published, were later refuted or amended in some way. It's too easy for people to find a paper that says what they want, and then put 100% stock in it (and as I said, my reading of the original paper seemed like the authors were more raising questions, and admitting to gaps in knowledge themselves, and the need for further investigation, rather then putting a stake in the ground and making specific, hard claims).
83037. Dikran Marsupial at 01:14 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Eric the Red s/we/I/ ? ;o)
83038. Eric the Red at 01:10 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Tom, Thank you for the reference and subsequent graphic. I do not think we want to enter the dispute between Viezer, Royer, Shaviv, etc.
83039. Tom Curtis at 00:50 AM on 11 June 2011
       Climate Consensus on a T-shirt
       detroitsylz @24, if they do, you can point out that one cold day does not a winter make. Everybody knows that a cold day, or week in a Northern Hemisphere May (or Southern Hemisphere November) does not mean that summer has been skipped this year and that Winter has come already. They know the vagaries of weather are not the same thing as the seasonal cycle, and that following that cold day, its going to get warmer, indeed much warmer before summer finally fades. So, if they are open to reason, they will also appreciate that one cold month (or year) does not end the trend of global warming. If they are not open to reason, on the other hand, they've probably heard the claim that scientists changed the name from "global warming" to "climate change" to conceal the fact that their theory had failed in the face of no warming. That, like many denier claims, is transparently false, but it means you do not get any rhetorical advantage from switching names.
83040. DSL at 00:49 AM on 11 June 2011
       Climate Consensus on a T-shirt
       I like it, but it's still an argument from consensus, and worry that it will be represented as a bandwagoning attempt by doubters and denialists. I'd prefer something a little more direct. Perhaps "Your Hum-Vee is diminishing the quality of life of my grandchildren" is a little too pugnacious. Maybe a top ten list is better: FRONT Top Ten Reasons Why Global Warming is Not a Problem
       1. God will fix everything.
       2. Technology will save us.
       3. Companies and corporations will begin to practice “ethical capitalism.”
       4. Gaia will bring balance back.
       5. More warming = more destruction = more jobs.
       6. The Arctic Ocean will be open for shipping.
       7. The physics is all wrong (that’s what this ex-meteorologist says on his blog).
       8. More CO2 = more plant food (I’m moving to northern Saskatchewan to grow corn).
       9. More CO2 = fewer coral reefs = safer surfing (yeah, baby!).
       10. Extreme weather events will mainly kill poor people, so poverty will end.
       Click here to learn more: SkepticalScience.com BACK Top Ten Reasons Why Global Warming is a Problem
       1. Sea level rise
       2. Drought
       3. Flooding
       4. Water shortages
       5. Agricultural disruption
       6. Human migration
       7. Plant, animal, and insect extinctions and migrations
       8. Increased weather intensity
       9. Greater energy demands
       10. (related) A more acid ocean
       Click here to learn more: SkepticalScience.com Perhaps have citations for each of the Back ten. Of course, I'd switch the ordering to lead with the tenth. The "click here" is just to get people to touch. Everyone likes to be touched. I'm a little touched myself.
83041. detroitstylz at 00:36 AM on 11 June 2011
       Climate Consensus on a T-shirt
       Cool idea, and I would totally buy one if only you had used the more correct term of "climate change" instead of global warming. We should stop using the phrase "global warming" because it invites more skepticism whenever there are weather events that people point to and say "see its not getting warmer!", as I'm sure you know...
83042. Tom Curtis at 00:19 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Eric the Red @45, Viezer et al 2000 did not allow for the change in uptake rate of O₁₈ that results from changes in the pH of water. Royer et al 2004 correct for pH changes due to high levels of CO2, and show almost complete consistency between the temperature record and the CO2 record: A later paper by Dr Royer show that many of the apparent discrepancies are found to not be so once we find high resolution proxies for the relevant periods. He also shows that the combination of changes to solar forcing due to the "faint young sun" plus CO2 forcing correlate exceptionally well with temperatures throughout the phanerozoic: Even the remaining discrepancies detailed in Royer 2007 have now largely been closed, as noted by Dr Alley in his famous lecture.
       Moderator Response: [Dikran Marsupial] sub tags fixed
83043. Dikran Marsupial at 00:19 AM on 11 June 2011
       Of Averages & Anomalies - Part 2A. Why Surface Temperature records are more robust than we think
       JMurphy An especially good point was that Prof. Jones highlighted the need for trends over longer timescales than the 16 years needed to achieve statistical sgnificance (cherry picking start and/or end dates to get the result you want invalidates the hypothesis test anyway - at least unless you account for the implicit multiple hypothesis testing).
83044. JMurphy at 00:14 AM on 11 June 2011
       Of Averages & Anomalies - Part 2A. Why Surface Temperature records are more robust than we think
       With regard to CRU, it's good to see Phil Jones finally clearing-up the 'not significant' comment so (wilfully) misunderstood by the so-called skeptics : Global warming since 1995 'now significant' I'm sure we will now no longer see this 'misunderstanding' in such a prominent position all over the Denialosphere... (Oh, is that a flying pig ?)
83045. Tom Curtis at 00:00 AM on 11 June 2011
       Christy Crock #6: Climate Sensitivity
       Eric the Red @34, for the 20% figure:

       Attribution of the present‐day total greenhouse effect Gavin A. Schmidt, Reto A. Ruedy, on L. Miller, and Andy A. Lacis Received 30 March 2010; revised 27 July 2010; accepted 3 August 2010; published 16 October 2010. [1] The relative contributions of atmospheric long‐wave absorbers to the present‐day global greenhouse effect are among the most misquoted statistics in public discussions of climate change. Much of the interest in these values is however due to an implicit assumption that these contributions are directly relevant for the question of climate sensitivity. Motivated by the need for a clear reference for this issue, we review the existing literature and use the Goddard Institute for Space Studies ModelE radiation module to provide an overview of the role of each absorber at the present‐day and under doubled CO2. With a straightforward scheme for allocating overlaps, we find that water vapor is the dominant contributor (∼50% of the effect), followed by clouds (∼25%) and then CO2 with ∼20%. All other absorbers play only minor roles. In a doubled CO2 scenario, this allocation is essentially unchanged, even though the magnitude of the total greenhouse effect is significantly larger than the initial radiative forcing, underscoring the importance of feedbacks from water vapor and clouds to climate sensitivity.

       (My empahsis PDF) Some indication of the climate sensitivity across a range of conditions is given by work by Pierehumbert et al (2011) from which Chris Colose shows this graph: The climate sensitivity at each point is given by the slope. In the upper section (non-snowball), climate sensitivity is never much below 3, and becomes significantly greater at higher levels of CO2. In the snowball Earth condition, climate sensitivity falls as low as 1.5 to 2 degrees per doubling of CO2. The increase in sensitivity for higher levels of CO2 is due to an increasingly powerful water vapour feedback. Chris Colose advices us to take exact numbers from these graphs with a large grain of salt, but the slopes at least are indicative. Pierrehumbert's graph is, of course, the product of a model. An evidence based approach to historical climate sensitivities can be found in Royer et al 2007. They take the fact that CO sequestration rates are controlled by temperature. Consequently, different CO2 sensitivities will result in different rates of accumulation of CO2 through out history. They model the CO2 cycle for different climate sensitivities and compare the results to the CO2 proxy record. As you can see, low climate sensitivities are inconsistent with the CO2 proxy record through out the phanerozoic, as are very high climate sensitivities. Admittedly the evidence is tenuous due to limitations in the proxy CO2 and temperature record in the past. But the evidence we have suggests a climate sensitivity around 3 degrees as a robust feature of the Earth's history.
83046. CBDunkerson at 23:55 PM on 10 June 2011
       Websites for Watching the Arctic Sea Ice Melt
       Thanks for the heads up Idunno! Fairly narrow band of predictions; 4.0 to 5.6 million km^2. Two 'public' contributions this year - one of them from Watts.
83047. adelady at 23:54 PM on 10 June 2011
       Climate Consensus on a T-shirt
       Well, just to be contrary... I like the Tshirt with the big lettering, and the mug with the text and graphic separated.
83048. Bob Lacatena at 23:53 PM on 10 June 2011
       Christy Crock #6: Climate Sensitivity
       47, skywatcher, Yes... I actually typed "hypothesis," and thought about it, and forget why I changed it to "theory," but you're right. On the ice sheets coming back... I think my main (natural) view is that in normal climate sensitivity time scales are utterly huge, meaning that thousands of years is a very short time frame. Human time frames of even hundreds of years, let alone ten or five, are utterly silly. So the point is that the ice sheets would grow back, and increase albedo, in their own good time, which to mother earth is more than fast enough. The same thing goes for the very slow transition in CO₂ levels under normal circumstances (abrupt glacial termination being a still unresolved exception). At the same time, it puts serious emphasis on exactly how crazy we are to be doing what we're doing. The earth's climate is a machine with a few knobs and levers and dials that the pilot lovingly adjusts, only a nudge here or a smidgeon there, and still he steers the planet between pretty marked extremes. We just barged into the cockpit, grabbed the biggest lever, and shoved it all the way forward, from lowest to highest, shouting "Yeehah! Flank speed! Go, baby, go!"
83049. Bob Lacatena at 23:47 PM on 10 June 2011
       Christy Crock #6: Climate Sensitivity
       45, Eric the Red, You are reading a lot (when you say "has less to do" rather than "may have less to do") into a letter which admits to and glosses over strong arguments that contradict the findings of their own work, and for which they admit there are large error bars in many areas. That said, the letter is also discussing climate 500 million years ago. I think that certainly there are some scenarios which would wildly vary climate sensitivity and the effects of certain mechanisms (in that case, CO₂) then versus today's values (for instance, the lack of an extensive, land based life ecosystem 500 million years ago, to either accelerate or balance many of the chemical interchanges). The authors say as much in their conclusion when they say "climate models ... are calibrated to the present ... and may thus be unable to reproduce correctly the past climate modes". To me, this is less of a comment on climate sensitivity, and more of a comment on the fact that the actual dominant mechanisms at play could have been very different (again, on a planet 500 million years removed from this one, almost as if it were another planet in the solar system). Basically, trying to do climate work today is very hard. Trying to do it for 500 million years in the past is a daunting task, and not what I'd use as a yard stick for evaluating the quality of other science, or values of climate sensitivity. I'm not saying paleoclimate is not valuable, but 500 million years is really stretching it. You also still have not yet posted your evidence and citations for the position stated in post 34 that climate sensitivity is low.
83050. skywatcher at 23:37 PM on 10 June 2011
       Christy Crock #6: Climate Sensitivity
       Sphaerica #42: a small nit - theories are the parts of science that are generally well-substantiated and tested, so presumably you meant hypotheses? I like your post at #38. I would add that there is an importance in considering the fate of the ice sheets. Regardless of the effects of presence or absence of ice on overall sensitivity (probably small but noticeable), we need to be aware of the fact that the ice sheets would not grow back as they are under present climate conditions. That is, if warming is sufficient that the ice sheets are melted, and then in the far future we are able to stabilise and manage global temperature, the ice sheets would not magically return to their present state merely by returning temperatures to those of the 19th or 20th Century. You would need to cool the climate very substantially lower than at present if you wished to lower the snow equilibrium line enough to grow the sheets back, due to the lost thickness of ice. It's part of the reason the ice sheets are at great risk from current warming, but it's not something that has a great bearing on the question of our climate sensitivity.

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