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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 65051 to 65100:

  1. Medieval Warm Period was warmer
    jzk - yes it would be neat if we had a whole bunch of global proxy data with sufficient resolution (detail), say at the annual (yearly) scale, but AFAIK there's not a great deal - and we know how worked up the fake-skeptics get about the tree-ring data. You just have to work with what you have. The real dagger to the heart of the MWP (to my mind) is the global circulations. Mann's reconstruction agrees very well with how we expect the circulations, and their teleconnections to operate. Not perfectly of course, but a warm MWP wouldn't agree at all. For instance ENSO (La Nina/El Nino) was weaker (lower amplitude) then, and the natural oscillation in ENSO was longer (around 80 years?). This is consistent with a cooler tropical Pacific than today. Additionally, the Amazon rainforest was wet - consistent with a more southward displacement of the ITCZ (inter tropical convergence zone) than exists today. Again suggesting a cooler global climate back in medieval times.
  2. We're heading into an ice age
    "The degree" varies wildly however. You can predict sunrise etc with very high degree of accuracy. You can also predict the changes in insolation due to the Milankovitch cycles which drive the ice cycle with a very high degree of accuracy, but climatic effect of that change also depends on other factors - especially level of GHGs. On the other hand, volcanoes are unpredictable with no known physical basis to a "cycle". A statistical recurrance period should never be confused with a prediction. Saying we are "long overdue" for an eruption smacks of pop-sci documentaries, and I would be interested if you have a science paper that says that. The basis for saying that there wont be an iceage soon is a/ Berger, A. and Loutre, M. F. (2002) which consider that orbital drivers, and b/ our GHG levels are getting to Pliocene levels - too high for an iceage.
  3. Volcanic Influence on the Little Ice Age
    Mann has a new paper out which discusses volcanic eruptions in the 13th Century too. RealClimate discussion here.
  4. Volcanic Influence on the Little Ice Age
    IIRC that region in Canada has been invoked as a likely key to triggering glacial periods, as snow lies on the Canadian archipelago and around Hudson Bay later during the summer as the summer sun weakens it reinforces the cooling trend allowing Hudson Bay to remain frozen all year round. This allows a very slow southward creep of summer snow which forms the begining of the glaciers. Norwegian Mountains and then the Scottish Highlands also play a role. That is that they are very close to the point where all summer snow can lie with a small amount of cooling. It is possible these volcanos did not cause the little ice age but their impact was enough to allow the build up of cold summers with snow all year round to drop the temperaturtes that was not able to clear fully before a slight drop in solar output refinforced the millenia long dropping solar energy in mid summer at high nothern latitudes. It is far from a done deal with this at the minute but it is a very interesting study and seems to just catch a point where the climate is valnrable to reinforcing changes.
  5. We're heading into an ice age
    OK this is stupid, we can predict things, but only to a degree. Apparently we are also long overdue for a super volcano eruption under yellow stone park, but it hasnt happened yet. The only thing that we have actually proved right from prediction, is that there is 365 days in a year, not counting leap years, So everyone can calm down, I dont think we will be in an ice age in any time soon.
  6. Medieval Warm Period was warmer
    Comparing 1999 - 2008 to 950 to 1250 is simply not a fair comparison. According to the Mann data, 1100 - 1250 was colder than average. (See his data set A for NH mean). How is that a relevant comparison? No such comparison occurs in Mann's paper.
  7. Global Sea Level Rise: Pothole To Speed Bump?
    If the Arctic ocean becomes ice free, we may see some real acceleration in sea level rise. A giant solar collector (the open Arctic ocean) beside a large block of ice (Greenland) may see a coupling of warm air rising from the collector to be sucked down by katababic cooling over the ice block. Basically a Foen Wind over a very large glacier. When a Foen wind hits ice, all the energy is concentrated right at the ice surface and is being imported from somewhere else, unlike solar radiation which can only supply so much energy per given area.
  8. Volcanic Influence on the Little Ice Age
    This theory that effects of the volcanic eruptions lingered for centuries after the events themselves seems like a new sort of 'tipping point' argument. That is, volcanic aerosols usually fall out of the atmosphere within a few years and have no significant long term effects... but this study is suggesting that a large enough set of volcanic events could introduce sudden sharp cooling which then becomes self-sustaining for hundreds of years. If that eventually proves out it would indicate that there are some major climate feedbacks that can be triggered on very short timescales... Arctic ice and ocean circulation for the study in question. There has long been concern about potential tipping points in these same areas with the gradual GHG warming we have been seeing, but this suggests it is possible that an otherwise temporary warming spike (e.g. El Nino) could result in a similar self-sustaining change.
  9. Michael Whittemore at 05:38 AM on 8 February 2012
    Public talk: Global Warming - The Full Picture
    Tom Curtis @25 I have finial found the right information, it would seem they are still debating the actual compensation scheme but due to caps on the amount the carbon tax can increase by and the some what "predictable" Internationale price of carbon will be, they have concluded that "Tax cuts will increase over time with a second round of tax cuts in 2015-16 that will further raise the tax-free threshold to $19,400, matching the impact of the carbon price to 2020." (http://www.cleanenergyfuture.gov.au/clean-energy-future/securing-a-clean-energy-future/#content05) It looks like I was wrong, John Cook was right to explain that compensation will cover most of the costs.
  10. Global Sea Level Rise: Pothole To Speed Bump?
    Time is an enabler for change, for without it nothing can change. Time simply allows processes to take their course, not cause them.
  11. NASA scientists expect more rapid global warming in the very near future (part 2)
    RP#50: Maybe Scafetta and West 2005: The climate sensitivity to the 22-year cycle, Z8, is approximately 1.5 times stronger than the climate sensitivity to the 11-year cycle, Z7, and, on average, the 22-year climate response lags Hale solar cycles by approximately 2.2 ± 2 years. These effects are predicted by theoretical energy balance models. In fact, the actual climate response to cyclical forcing is stronger at lower frequencies because the damping effect of the ocean inertia is weaker at lower frequencies. They show a relatively poor quality graph (their Fig. 4) illustrating this lag. 2.2+/- 2 years seems like very high uncertainty; 18 months is well within that window. The 'damping effect' statement makes sense, but could be more clearly stated: ocean thermal inertia reduces climate response to short-term drivers. If the response to a 22 year cycle is much greater than the response to an 11 year cycle, such short period events like ENSO cannot be causes for climate change. The gradual buildup of GHGs, on the other hand, is a long period driver.
  12. Michael Whittemore at 04:35 AM on 8 February 2012
    Public talk: Global Warming - The Full Picture
    Tom Curtis @25 Of course you say, I would like a link to that fact?
  13. NASA scientists expect more rapid global warming in the very near future (part 2)
    Muon @ 48 - the peer-reviewed literature doesn't make it clear, but these are two separate issues. Firstly, the lag in surface air temperature response to a change in solar irradiance is about a month, but the ocean response is on the order of 18-24 months. Still trying to track down a paper that deals with this issue specifically. It's mentioned in a few papers, but only in passing.
  14. Pete Dunkelberg at 04:06 AM on 8 February 2012
    NASA scientists expect more rapid global warming in the very near future (part 1)
    Link needed for IanC's # 16.
  15. Global Sea Level Rise: Pothole To Speed Bump?
    Dumb questions (perhaps): Does time cause climate change? If not, why all the consternation about time-series plots of surface temperatures? If so, how exactly does time cause climate change?
  16. New research from last week 5/2012
    Do you think Von Deimling talked to the Russians...? http://www.skepticalscience.com/arctic-methane-outgassing-e-siberian-shelf-part2.html
  17. Public talk: Global Warming - The Full Picture
    Michael Whittemore @24, it is of course 50% given back to the people, and most of the remaining funds used to compensate trade exposed industries, schools, hospitals etc, or to fund research on renewables.
  18. Still Going Down the Up Escalator
    Tamino (Grant Foster) has an excellent new post explaining how you can make a reasonable estimate of the uncertainty of a trend without knowing the uncertainty of the data, ie, why Briggs is wrong. Interesting read.
  19. Michael Whittemore at 02:26 AM on 8 February 2012
    Public talk: Global Warming - The Full Picture
    Tom Curtis @23 Will there you have it, %50 of the revenue given back to the people sounds good to me. I have been thinking about it and they would be able to do it with increased tax rebates at the end of each year. But I worry that he is only talking about the next couple of years before the ETS starts? I also have concerns that they will not be making as much as they do from a tax as they will from an ETS. But for now I will agree that an adjusted compensation rate of %50 of the revenues sounds fair. It would be good if they had that in writing though.
  20. Public talk: Global Warming - The Full Picture
    Michael Whittemore @22, it seems that I need to withdraw that the compensation will be increased "... by requirement of law". Never-the-less, it is the governments stated intention to do so:
    "Speaking after a Swan speech at the National Press Club, the Climate Change Minister, Greg Combet, said the macro-economic outcomes from the modelling proved carbon pricing was a ''manageable reform'' which would not bring about the ''end of the world''. Mr Combet said household compensation - to be funded with 50 per cent of the revenue from the tax - would be regularly reviewed to make sure the real level of assistance was maintained as the carbon price rose. Meetings of the multi-party climate committee will continue today to negotiate demands for compensation and extra spending that add up to more than the revenue the carbon tax will raise."
    (My emphasis) There is, of course, "many a slip twixt cup and lip", particularly where government promises go. Never-the-less the return of adequate compensation is fundamental to the logic of the scheme, and is unlikely to be tampered with.
  21. Global Sea Level Rise: Pothole To Speed Bump?
    SteveChase at #41:
    Dr. Hansen's graph isn't sigmoid, it's an asymptotic progression and he didn't say when it would end.
    Erm, I think that you mean geometric (although that too is a clumsy term), not "asymptotic". If a progression were "asymptotic" to the independent variable (time), you'd have the interesting phenomenon where the progression wouldn't reach a particular moment. Perhaps the planet's accelerating toward c with respect to your reference frame...? If a progression were asymptotic to the dependent variable (temperature), and if it's initially accelerating or 'geometric' (as Hansen's trajectory is), then I'm not-so-sorry to tell you that the trajectory will be approximately sigmoid. Hansen's trajectory appears to be continuously exponentially increasing only because it's extrapolated to 2100, and no further. You may like to re-interpret what this means, but simple physics dictates that the overall curve (that is, when extended beyond the 2100 upper x-axis bound that was shown on a simple graph) will be sigmoid. And one day, when current society is merely a layer in the fossil record, that trajectory may even head downward. None of this changes the fact that with the appropriate ∆T/∆t, ∆SR will approach (for a relatively brief period) the order of magnitude of millimetres per day. Your argument can only be whether ∆T and/or ∆t are likely to be of the values that would result in Hansen's predicted 2100 rate of sea level rise.
  22. apiratelooksat50 at 01:18 AM on 8 February 2012
    NASA scientists expect more rapid global warming in the very near future (part 2)
    Tom Curtis at 10 Looks like we were both right in a way. Kind of like kissing your sister. I contacted Mr. Hansen and asked him for clarification on his intent of using "implies" in the paragraph. In an excerpt from his e-mail: "That's a good point -- not a very precise word -- what I meant was that we could conclude -- of course that is a pretty strong statement -- we will see if referees agree with my assertion, when I submit the paper for publication in ~ a week or so." It will be interesting to see the language used in the final version if the paper is published after peer review.
  23. Michael Whittemore at 01:12 AM on 8 February 2012
    Public talk: Global Warming - The Full Picture
    Tom Curtis @21 Can you show me where it states income tax will decrease/increase with the amount the government makes from the ETS? Because if the price of carbon is floated then it will fluctuate, and I don't see how they can keep on adjusting income tax. The reason they started the carbon tax at $20 a tonne was so they would not have to compensate people as much as when it becomes an ETS. Also to be clear I am not saying the government will run out of compensation funding, I am saying they will pocket it. I read they will be setting up some sort of bank that will determine what to do with the funds, but with a fluctuating ETS it will not be income tax they use to distribute the funds. My point regarding a green power system, is that they would not need to buy carbon fuels or carbon credits. I agree with your point regarding the use of solar panels, but with such a mass push for green power the costs of the panels would come down. My not very well thought out plan of forcing the power network to become green, has me thinking that with large scale wind farms and huge solar plants they would not require much money to run. The cost to the customer would surely be low. Many towns are now buying wind farms to supply them power because in the long term its very cheap. Your point about people reducing their energy consumption is right, but its not nice. People dont waste energy, its expensive as it is, making it cost even more is sad. I get it though, a carbon tax is a good option, I just would rather the government step in and assist making the power network green. That way we wont all have to become energy saving hippies.
  24. Global Sea Level Rise: Pothole To Speed Bump?
    Steve Case - "Were I to live to 2101 I would be surprised to see the ocean creep up that fast." Then you are putting forth either the Argument from Common Sense (recommended link - very relevant) or the Argument From Personal Astonishment. Both are logical fallacies - when your personal opinions are contradicted by actual data, the data wins. As to asymptotic versus sigmoid - ice loss will taper off, but possibly only when we run out of ice... It depends on what our future emissions are.
  25. Global Sea Level Rise: Pothole To Speed Bump?
    Steve, the IPCC AR4 values you claim as 'contradicting' more recent studies explicitly exclude accelerating land ice export because it was only slightly documented at the time; "Further accelerations in ice flow of the kind recently observed in some Greenland outlet glaciers and West Antarctic ice streams could increase the ice sheet contributions substantially, but quantitative projections cannot be made with confidence" While it is amusing to see a 'skeptic' using modeled results from the IPCC to 'refute' direct measurements from GRACE, the simple fact is that the IPCC AR4 estimates are now known to be significantly conservative. There is no "conflicting evidence" here. Just a past incorrect estimate vs current measurements.
  26. NASA scientists expect more rapid global warming in the very near future (part 2)
    "global temperature change caused by solar variability lags solar irradiance by about 18 months." The spamboy did raise a valid point: FR2011 determined a lag between TSI change and temperatures (they used both satellite and surface records) of 1 month. This was in agreement with results of Lean and Rind 2008. Putting an 18 month lag into FR's data (available at you-know-who's blog) destroys all semblance of fit.
  27. Global Sea Level Rise: Pothole To Speed Bump?
    @ Steve Case: What part of "Decadal Doublings" (from your Hansen quotes) don't you understand? You continually post here with handwaving assertions based on linear thinking when the records are fraught with evidence of exponential change. In that you cite Hansen, quote Hansen, then cherry-pick the parts that support your agenda & elide the rest, your "argument" devolves to straw.
  28. Global Sea Level Rise: Pothole To Speed Bump?
    RE: #38 Bernard J. at 16:14 PM on 7 February, 2012 I get the very same numbers you get, and if you continue the progression out to 2101 it is indeed one millimeter per day. Were I to live to 2101 I would be surprised to see the ocean creep up that fast. Comparing Pulse 1A to today or 2100 is apples and oranges. We currently don't have continental ice sheets in the temperate zones waiting to melt. There is certainly enough water locked up in the Greenland and Antarctic ice sheets to cause such a rise if they were to melt. However there's conflicting evidence of such melting. Table 10.7 in the IPCC's AR4 tells us that the contribution of Greenland and Antarctica to sea level rise by 2100 will be negative. Elsewhere The GRACE studies say the opposite. Dr. Hansen's graph isn't sigmoid, it's an asymptotic progression and he didn't say when it would end. He only plotted it out to 2100. I extended it by one year to get the one millimeter per day number. My mathematical "Straw man" as you've put it merely puts Dr. Hansen's curve in actual numbers that can be understood by ordinary people who can decide for themselves whether or not such a scenario is likely to come to pass.
  29. New research from last week 5/2012
    dorlomin, they also apparently managed 49 proxies with annual resolution... which is more than the total number of proxies in any previous study of the same sort. Of course, being Ljungqvist, he still manages to word things in a way that will almost certainly give rise to more denial. For instance; "We conclude that during the 9th to 11th centuries there was widespread NH warmth comparable in both geographic extent and level to that of the 20th century mean." This will almost certainly be turned into denier claims that 'the MWP was just as warm as present without high CO2, ergo it is just natural variability'. The problem with that 'logic' of course being that the end of the 20th century (and start of the 21st) was much much warmer than the mean. It also doesn't include the southern hemisphere, which is currently warming but generally believed to have been cooling during the 'MWP'. Still Ljungqvist 2012 does also say that the current rate of warming is much higher than anything in the past 1200 years. The data seems to be slowly pushing him towards the mainstream. At this point I have to wonder how much more the ~1200 year NH data can be refined. Where we really need more attention is trying to build an equally robust view of SH temperatures and/or going further back in time. Sapient Fridge - Guy Stewart Callendar was one of the early proponents of AGW theory. His belief that early 20th century warming was caused by humans ultimately turned out to be largely incorrect (most of it was due to a solar maximum), but his efforts to document increasing atmospheric CO2 levels showed that human emissions were causing an increase in greenhouse gases which would eventually (i.e. now) cause significant warming.
  30. Public talk: Global Warming - The Full Picture
    Michael Whittemore @20, when the Australian Carbon Tax enters the ETS stage, the emissions permits will be bought by auction from the Australian Government. The money so raised will be used, by requirement of law, to compensate the Australian people. Because the permits are purchased from the Government, the amount of money spent on permits is the amount of money available for compensation. Therefore suggesting that the compensation will dry up in five years time is fundamentally misleading. That does not mean there will be no cost. If a power company generates power using a solar thermal power plant, at a slightly greater cost per kwh than generating via coal, but cheaper overall because there is no need to purchase carbon credits, the additional cost difference between generation by CST and coal will still be passed onto consumers, but will not be available to fund compensation. That means the actual direct costs of abating carbon emissions, and only those direct costs will feed into the market. Of course, in the short term, the cheapest way for consumer to reduced costs will be to reduce energy consumption, which will give them cheaper power bills overall, allowing them to pocket some of the "compensation" as profit. In the long term, such a scheme may end up reducing overall power costs with a combination of reduced consumption and low cost renewable supply. Of course, if people do not reduce consumption, and renewables do not come down in cost, then overall costs will go up.
  31. NASA scientists expect more rapid global warming in the very near future (part 2)
    Rob#45 "Because of the ocean's thermal inertia, global temperature change caused by solar variability lags solar irradiance by about 18 months." The NASA statement refers to global temperature change. This should include all of ocean, land + air temperatures. We know that the absorbed energy in the oceans must show up as raised temperatures or phase change so what the statement should say is that because of the ocean's thermal inertia, temperature rise in some parts of the system (presumably air and surface) is delayed by heat transport through the oceans.
  32. Global Sea Level Rise: Pothole To Speed Bump?
    IanC @31 The deeper ocean seems to be gaining some heat content but it is small compared with the surface water and it not well measured. The upper ocean has much better measured coverage. Here is an article that goes into the contribution of the deep Pacific ocean on the energy budget. Recent Bottom Warming Water in the Pacific Ocean. Quote from article: "Thus, abyssal Pacific Ocean heat content variations may contribute a small but significant fraction to the earth’s heat budget."
    Response:

    [DB] Your source is 5 years out-of-date.  Use the Search function to find posts referencing far more current materiel.

  33. Michael Whittemore at 22:12 PM on 7 February 2012
    Public talk: Global Warming - The Full Picture
    @The Skeptical Chymist The compensation that is put in place right now will only cover the cost of $20 a tonne carbon tax. When the carbon tax is a floating ETS price, it will rise. The greens wanted it to start at $100 a tonne. I would like you to clarify where it stipulates how much the ETS can float. But yes my wording did suggest that the compensation will stop completely, but my point was focused on John Cooks expectation that compensation would cover the costs to the Australian people. Like I said, as the ETS prices rises, there will not be more income tax cuts. This compensation package is just designed to misleads the people into thinking they will be better off. But dont get me wrong, a carbon tax is a good way to go about reducing CO2. Forcing power companies to go green would not need the public to reduce their CO2 outputs, because all of the heating/cooling and every other electrical devise would be green. This would include office buildings and shopping centers, all green. With the reduced costs to the power companies, electricity prices would drastically fall, forcing the public to use electric cars. But this is just something I thought up off the top of my head, so its really only a pipe dream.
  34. Sapient Fridge at 21:56 PM on 7 February 2012
    New research from last week 5/2012
    I didn't understand the Callendar paper abstract at first because it gave a temperature rise of 0.005C per year for 50 years, giving only a 0.25C rise. That seemed low for the last 50 years. Then I spotted that the paper was from 1938!
  35. Global Sea Level Rise: Pothole To Speed Bump?
    @ agwnonsense 27 Where you are might not be experiencing the same sea level rise as everywhere else. Link to sea level rise map. Some regions are seeing faster, some slower and some are even falling (versus the average). This is mostly short term noise, you can't keep expanding the ocean and building up ever bigger differences, the water will trickle around to balance it out (as a rule, it depends on other stuff). Also, do you know if where you are living is experiencing tectonic uplift, or post-glacial rebound? For example, the north of the UK is currently rising, whilst the south is sinking because the north used to be weighed down by ice. Just like throwing weights overboard, the floating object straightens out a bit afterwards. This means that the southern UK is seeing much more apparent rise than the north. As for the problems: so far the last 30-odd years have only been about 90% faster than the last century. But if that acceleration happens again you'll be seeing more serious effects. The UK for example is talking about hundreds of millions of pounds a year of extra sea defences assuming that the best cases are right.
  36. New research from last week 5/2012
    Am I reading that right and Lungqvist managed 120 proxies? Blimey that is some effort.
  37. Michael Whittemore at 19:15 PM on 7 February 2012
    2012 SkS Weekly Digest #5
    Jose@6 The middle of the cartoon is not half way between the expected climate change, the abyss is denying the science, there is no middle, rather you accept the science or you dont. United States is taking the roll of not listening to the science, you are suggesting that the United States are going to be accepting the science half way, this is not the case. Even if they did the bare minimum of what the IPCC suggest would be good enough.
  38. NASA scientists expect more rapid global warming in the very near future (part 2)
    Rob @45 Sorry about that ... I think most of my confusion was not figuring out that 0.25 W/m2, when distributed through 10+ cubic meters of sea water, is a very tiny signal indeed ... so inertial effects really could predominate. Thanks.
  39. New research from last week 5/2012
    Fixed, thanks.
  40. NASA scientists expect more rapid global warming in the very near future (part 2)
    Old Mole - "Once again I am having a hard time puzzling this out, and would be grateful for a link to which paper by NASA scientists you rely on" Yeah, well some of the comments on this thread puzzle the heck out of me. I think this relatively easy to follow, but perhaps not. The NASA scientists are those mentioned at the top of this post, and the analysis linked to in the blog post. They state: "Because of the ocean's thermal inertia, global temperature change caused by solar variability lags solar irradiance by about 18 months." I've seen mention in other literature that the lag is closer to two years. But I wouldn't be able to link to one at the moment. See what I can track down as others seem to be having problems with the notion of ocean thermal lag too. and Judith Curry..... That was organic spambot Mace, JDey, or whatever he calls himself, impersonating Judith Curry.
  41. Major Study of Ocean Acidification Helps Scientists Evaluate Effects of Atmospheric Carbon Dioxide on Marine Life
    William - I don't know if Doug Mackie is going to address alkalinity in the next installment on the chemistry of the ocean, but it's hardly relevant to changes occurring today. The main supply of alkalinity back to the ocean is via chemical weathering of silicate and carbonate rock and that operates on timescales of hundreds of thousands of years - at the least. The other mechanism, the dissolution of carbonate sediments, also takes place on timescales such that it is also no use to humans or marine life alive today, or in the foreseeable future. There are a number of upcoming posts on the subject of ocean acidification. Once all are completed, I'll tie them all together so the "big picture' is plain to see.
  42. NASA scientists expect more rapid global warming in the very near future (part 2)
    Rob Painting @34 "The suns energy has already been absorbed by the oceans and takes about 18 months for them to warm up and exchange all this heat with the atmosphere, thereby affecting surface temperatures. If you wish to contradict these NASA scientists, some supporting literature would be handy. Otherwise it's just an uninformed opinion." Once again I am having a hard time puzzling this out, and would be grateful for a link to which paper by NASA scientists you rely on. You say with confidence "18 months" and Judith Curry (in a post made in the last week that I can't find at present) suggested that it was more like 1 month. I am not sure there is really much of a contradiction, though. When you say "all this heat" you are no doubt correct ... but how much of "all" remains after 17 months? It was seem, based on no more than intuition, that there would be a least an order of magnitude difference between the heat released through evaporation in month 1 than the amount released in month 17. Please correct me if my grasp of fluid thermodynamics is at fault, and give me some idea of what the curve for energy release from the ocean would look like for a solar event, largely in the form of light energy in the visible spectrum and therefore confined largely to a relatively shallow surface layer, at least initially.
  43. NASA scientists expect more rapid global warming in the very near future (part 2)
    Don9000 - Much ado about nothing. It was a simple inadvertent omission that I don't consider materially changes the intent of that part of the analysis - it's clearly explained in the body of the article that extreme warm events will increase markedly with global warming. Anyway, I've emailed Dr Hansen. If he replies and feels it should be changed, I will do so.
  44. Global Sea Level Rise: Pothole To Speed Bump?
    Steve Case at #35:
    Skywatcher - The calculations I've done is to figure out that by 2101 Dr. Hansen's "plausible" scheme would be filling the oceans up at a rate of one millimeter per day.
    I vectorised Hansen's graph, and keeping in mind that the resolution of the line was not wonderful, I obtained these additional rates of sea level rise: 2050: 0.0 mm/day (id est, below resolution) 2080: 0.2 mm/day 2090: 0.4 mm/day So your figure is ballpark, but you seem to think that it is surprising. You also seem to be completely ignoring Skywatcher's comment immediately preceeding yours, that Meltwater Pulse 1A added 20 m to sea level from ice sheets in as little as two centuries... In such a scenario, where ice is catastrophically melting as a consequence of sudden warming, it is entirely feasible for a millimetre order of magnitude to be added per day. However, the trajectory will be sigmoid, so the interval of time where such rise occurs will be short. The rates of rise for the preceeding decade intervals should have clued you in to the fact that the millimetre(s) per day phase would be short, and in the middle of the 'catastrophic' period. Your quibble is really a mathematical straw man. Given a particular global ∆T there will be a corresponding ∆SL, occurring over a corresponding ∆t. Fact. If Hansen's scenario comes to past, the rate of ∆SR will be in the order of millimetres per day around the point of inflection of the trajectory. Fact. And if it comes to pass, humans alive at that time will not be thanking humans alive today for having sat on their hands and argued about "how many Angels may fit upon the point of a Needle", to quote the theologian Baxter.
  45. keithpickering at 15:50 PM on 7 February 2012
    New research from last week 5/2012
    I think the Callendar abstract should read: "The temperature observations at 200 meteorological stations ... ".
  46. NASA scientists expect more rapid global warming in the very near future (part 2)
    Don9000 @41, with respect, your background may be in English, but mine is in logic and philosophy (including the philosophy of language, science and epistemology, for what it is worth). The imprecise language found acceptable in English continually makes my skin crawl as a logician. The worst offense is the standard usage of saying "all are not" when what is meant is that "not all are". The difference between asserting that no member of a group has a particular property (all are not) and asserting that there are some members who do not have it (not all are) is apparently to subtle for the average English speaker. The same problem occurs in imprecision of terminology. "Implies" means that a relationship stands between the two propositions which supports modus ponens as explained @10 above. That is all that it means, in either English or in logical usage. It is used in common speach to soften assertions, but that usage is as inconsistent as asserting that "all are not" when you mean that "not all are". The question is, then, are the writers of a scientific paper more likely to be using the precise logical meaning of the word, or the common street misuse of the term. Choosing to believe the latter while ignoring the context of utterance is hardly credible. From context, the "implies" is not a strict justification of "modus ponens" because the implication is probabilistic, but neither is it a mere weakening of the assertion. The qualification on the assertion is merely the qualification on all empirical assertion. That is, to the best of the authors knowledge the two heatwaves would not have occurred without global warming; but the best of their knowledge is not claimed to be perfect.
  47. Still Going Down the Up Escalator
    BTW, SkSer John Russell had a guest post today at ClimateBites titled 'Escalator' Critics Miss the Point. John notes that the "skeptics'" quibbling about the data simply misses the main point of the graphic, which is to expose the deceptive technique known as "cherry picking." And it achieves that goal admirably.
  48. Climate change policy: Oil's tipping point has passed
    JP40 - interesting but a/ has anyone built a working economic fusion plant for the tech yet? b/ what would the cost of that power be if it worked? (A question that I know requires details of the fusion reactor as well the transport scheme). A working technology that is also cost efficient would be of interest but you can surely see why say windmills and fission are more interest at the moment.
  49. Still Going Down the Up Escalator
    Cherry-pickers of course hate "The Escalator." It strips their ploy naked, exposing its fallacy! (phallacy?) :)
  50. NASA scientists expect more rapid global warming in the very near future (part 2)
    Rob, I'm coming to this a bit late in the day, but I hope my comments will make sense! I found your summary effective, but must in part agree with apiratelooksat50 that you have been a bit unfair where that one passage is concerned. So . . . I'm glad to see that the original passage referenced by apiratelooksat50@9 is present in this post, since it shows that your summary of it is simply a bit jazzed up for our reading pleasure. On the other hand, while I am not a scientist, I do have a doctorate in English, and I can tell you that the distortion imparted to the original by you in the summary section would raise flags if a similar passage, without the original, surfaced in a student essay in disciplines where being faithful or fair to the source matters. Since many of us, on the subject of global warming, are students, I think we need to be very careful where sources are concerned. Because you provide the original, if I saw a similar paraphrase in a paper submitted to me, I think I would point out that you should be more temperate in your conclusion. To put it bluntly, I think you have unfairly implied that what you write as a summary is what the authors have stated. The word "state" is a very strong signal word, and should really only precede a quotation. The proper way to handle this would have been to reproduce the original passage (as you do with that last summary point): it is a pithy one, so quoting it once again makes good rhetorical sense. You could also revise the passage. Here is the way you wrote it: "A more than tenfold increase in extreme warm events, has the authors state that we can attribute the monster 2010 Moscow summer heatwave, and the 2011 Oklahoma/Texas heatwave, to global warming." I think something like this would be fairer to the source (though less pithy--most pithy passages are hard to succinctly paraphrase): Global warming is implicated in the recent more than tenfold increase in extreme warm events, including specific events like the summer 2010 Moscow heatwave and last summer's heatwave in Oklahoma and Texas. Hope this is clear! I enjoyed (if I can say that about more bad news regarding AGW) reading the article and learned a few things along the way. Don Blume

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