RealClimate logo


Unforced Variations: Oct 2013

Filed under: — group @ 1 October 2013

This month’s open thread. We’re going to guess that most of what people want to talk about is related to the IPCC WG1 AR5 report… Have at it!


286 Responses to “Unforced Variations: Oct 2013”

  1. 201
    SecularAnimist says:

    Retrograde Orbit wrote: “I suggest we do not approach the skeptics with the expectation of malice”

    Those like Inhofe who deliberately, repeatedly and loudly proclaim what they know to be lies, who abuse their positions of power to attack climate scientists, are not “skeptics”, and they are by definition malicious.

  2. 202
    Mal Adapted says:

    Ray Ladbury:

    Blaming it all on political ideology, malicious intent and lack of intelligence gets us nowhere.

    I think we’re in vehement agreement, Ray. I certainly can’t blame my own non-zero carbon footprint on any of those 8^}. OTOH, naive presumption of sincerity and good will on the part of motivated deniers like Inhofe won’t get us anywhere, either.

    I honest don’t know how to make further inroads. I’m afraid only the obvious impacts of warming on people’s daily lives will. Those will fall unpredictably on accepters and deniers alike.

  3. 203
    Patrick 027 says:

    re 197 Mal Adapted – technically that doesn’t prove that he doesn’t believe what he’s saying (not that this nuance prevents me from having harsh feelings). Not that I’ve been pouring over the evidence myself, but I’d zero in on an interview by Rachel Maddow for a possible hint of that (?) (I didn’t watch it, actually, I only read about it, so there’s nuances I could be missing, but the gist I got was that he decided global warming wasn’t real when he found out it would cost money. But was he joking?)…

    re Ray Ladbury – as to your question of what would I do (http://www.realclimate.org/index.php/archives/2013/10/the-ipcc-ar5-attribution-statement/comment-page-2/#comment-417699 ) (sorry for being lazy about link formatting), aside from the science itself, I might try to make an appeal based on the party branding ‘personal responsibility’. (Although I’m not sure if that term is meant to mean what I assume it does.) Also, the economic argument – AGW will cost us; when people pay for the costs of their choices the market tends towards greater efficiency. There’s also the property rights angle, although that gets fuzzy.

    (I think it’s really hard to just have an off-the-cuff conversation where you find out someone doubts AGW or the seriousness of it (or the solutions for it) and just try to argue against that position. I think it helps to ask why, first, so you know which issue to address.

    You also have to know when to give up on someone, so you don’t wear yourself out.)

  4. 204
    Patrick 027 says:

    totally off-the-wall correction – at the end of my July 190 http://www.realclimate.org/index.php/archives/2013/07/unforced-variations-july-2013/comment-page-4/#comment-396472 , I wrote: “so we have a map of varying wave vector over space, and in some places intrinsic frequency goes to zero (critical lines) and becomes imaginary, etc.” I should have said that a component of the wave vector becomes imaginary. Imaginary wavevector components indicate exponential decay (or growth) over space ((can be?) indicative of total internal reflection); imaginary frequency indicates exponential growth (or decay) over time.

  5. 205
    Patrick 027 says:

    … and there’s more to what a critical line actually does but I’ll get to it in a time and place where I can do a good job of it (for now, wavevector component becomes imaginary specifically if it is necessary to satisfy the dispersion relation for whatever frequency is being imposed. Is that always across a critical line? I need to go back and check.)

  6. 206
    Gator says:

    Ray L — the one thing Inhofe and Cockburn have in common is an emphasis on denying that climate change is happening because they refuse to deal with the implications. I.e., climate change could require big changes therefore it is not happening. Inhofe refuses to believe it because of taxes and his oil company friends; Cockburn apparently refused to believe it because it might lead to more nuclear power plants and fear of how dealing with CO2 generation might impact the third world.

    The common thread is not seeing the world for what it is, but what they want it to be and working backwards.

    Political ideology drives this. Malicious intent drives this. Lack of intelligence drives this.

  7. 207
    Ray Ladbury says:

    Gator, You can hardly claim that Cockburn was unintelligent or malicious. Likewise Freeman Dyson.

    The problem is that both have fallen victim to a logical fallacy–argument from consequences–because having to deal with climate change is an unwelcome distraction from their higher priorities. These are people we should want on our side. Inhofe…well, let’s just say I’m not sad he’s on the other side.

  8. 208
    Radge Havers says:

    Case by case, “know your audience.”

    Thoughts on investigating the crowd psychology of certain primates:

    “Biased self-perception,” the authors write, “predicted voting behavior in the 2012 presidential election even after controlling for objective political-orientation scores.” So it doesn’t really matter what they believe, the authors are concluding. Sorting people by shared belief is a failed exercise.
    http://www.nationaljournal.com/politics/science-says-nbc-s-hope-for-the-american-center-is-wrong-20131016

    Contemplations:
    http://clotureclub.com/tea-party-insult-generator/
    (insults PO’d tea partiers hurled at Boehner)

  9. 209
    Hank Roberts says:

    Climate models have trouble with clouds — and so do weather models; here’s a good summary about the difficulty of predicting low clouds even one day ahead:

    Why Do Low Clouds Burn Off on Some Days and Not Others?

    … predicting low clouds is very hard and our computer models are very poor at dealing with them. To show how bad it can get, here is the forecast from the UW high-resolution model of low clouds at 8 AM this morning. Nearly no clouds over Puget Sound. Embarrassing. And this weaknesses in shared by most other weather prediction systems.

    Forecasting low clouds plays to all my profession’s weaknesses. Our computer models often don’t have enough resolution in the vertical to properly simulate shallow clouds. Our boundary-layer schemes, the software used to simulate the lowest layers of the atmosphere, often fail when the atmosphere is stable (warm air above cold air is an example of a stable situation), producing anomalous mixing in the vertical that destroys low clouds. We often don’t have enough information from observations to properly describe the lower atmosphere, a description that forecast models need to make skillful forecasts.

  10. 210
    Walter Manny says:

    Haven’t posted here for a long time and curious to know what RC’s stance is these days on the so-called pause in global warming. There was a post dedicated to the topic in October 2009 (Stefan), but has there been or will there be an update that reflects current mainstream thinking about it?

  11. 211
  12. 212
    Hank Roberts says:

    For those who haven’t been reading for a few years,

    this particular fairly short thread is well worth reading — particularly John Mashey’s comments there: http://scienceblogs.com/deltoid/2008/07/31/monckton-flunks-latin/comment-page-1/

    You’ll see much that gets repeated.
    As I recall, the much-needed category “goldfish troll”* was defined somewhere around that time at that site.
    —————–
    * “… makes simple-minded arguments, which are debunked forthwith…. shows signs of understanding why his arguments are bogus at the time – but then swims around the bowl a couple of times and breathlessly repeats them again.”

  13. 213
    Walter Manny says:

    Thanks, Patrick, for the reference, and Hank for the reminder of not my finest hour! Good to see you’re still here.

  14. 214
    Hank Roberts says:

    I think most of us oldtimers have gotten to understand that “what’s your source for that belief, where can I read what you rely on for it?” is appropriate to ask someone who proclaims a belief — no matter what the belief. There are lots of scary stories out there.

  15. 215
    Hank Roberts says:

    a science fiction writer’s comment:
    What the astronaut said.

    Those needs aren’t just about inspiring scientists and explorers. Those of us watching from the periphery need to think about why their work is important, and why we should throw our weight behind it. Public enthusiasm for space exploration is still alive, but it’s fragile, and it won’t be helped along if we don’t look past the narrow view of our present circumstances. From a human standpoint, space has only ever been the realm of society’s upper echelons—the military elite, the intellectual elite, and now, the affluent elite—but it belongs to all of us. That’s a hard thing to see, though, if we focus only on the here and now. We have to keep telling the stories that drive us to make steps forward. Maybe those steps aren’t for us. Maybe they’re not for our kids, or even our kids’ kids. But if we keep moving, some of those futures we’ve imagined might one day become reality. It’s possible. Truly, it is.

    Like the astronaut said, we just have to keep getting them up there.

  16. 216
    Andreas T says:

    I have been keeping an eye on antarctic temperature (anomalies) and if I am seeing this right http://www.esrl.noaa.gov/psd/map/images/rnl/sfctmpmer_180a.rnl.html
    it has been unusually warm all of SH winter in east antarctica especially. I would like to know more about this, does anybody know of sources on this? I know it is rather soon for a fully reasoned comment, but I’d like to know if it could be significant and worth following up.

  17. 217
    Hank Roberts says:

    Andreas, this is on the west antarctic, but poking along these lines with Scholar may help: http://www.nature.com/ngeo/journal/v6/n5/full/ngeo1778.html
    Nature Geoscience 6, 372–375 (2013)
    doi:10.1038/ngeo1778

    It is unknown whether these changes are part of a longer-term trend. Here, we use water-isotope (δ18O) data from an array of ice-core records to place recent West Antarctic climate changes in the context of the past two millennia…. anomalies comparable to those of recent decades occur about 1% of the time over the past 2,000 years.

  18. 218
    Dave123 says:

    Ray@200- I’ll suggest another analysis of the Koch Bro’s thinking. There is no malicious intent there, but they do see malice from others. These guys both have engineering degrees from MIT and they’re no dummies. But as the inheritors of an ongoing business they’ve experienced life at the top. If like most people you remember your successes, and forget your slip-ups, they’ll remember the times they knew better than their technical staff, for what ever reason. The times the staff was right don’t count. So they have an improperly inflated sense of their own judgement. (I’ve seen this in all kinds of people at the top of organizations- it may also be a survival trait- if you can’t shake off being wrong, and focus on how right you are, you’ll get depressed)

    This kind of self-reinforcing ego isn’t something owned because of one’s political leanings…it’s just a matter of being/getting to a seat of power. So there is also a tendency to see disagreement as attacks, and hence malice. Environmentalists are out to get them.

    And those coke piles in Chicago…well, that’s just the realities of the petrochemical business…don’t expect a white-gloved world.

    http://thinkprogress.org/climate/2013/10/15/2778921/koch-brothers-tar-sands-chicago/

    … at least that’s how real, free American men see it.

  19. 219
    Patrick 027 says:

    …well, that’s just the realities of the petrochemical business…don’t expect a white-gloved world.“…”… at least that’s how real, free American men see it.

    Um, what?

    (Is that a parody of tea partier/conservative views liberals/enviromentalists? (If so, and if accurate… Do they think the mud at Woodstock was some sort of exclusive spa treatment? Then why can’t the Kochs be ‘real, free American men’ and just pile the pet. coke up in their living rooms.) PS it might be easier to accept if it were at all necessary – nobody really needs people to be digging around in Alberta for that stuff.)

  20. 220
    Nigel Williams says:

    I’ve only read the abstract and some news reports, but this is pretty alarming stuff:

    http://www.abc.net.au/news/2013-10-10/record-temperatures-could-hit-as-early-as-2020/5013442
    http://www.nature.com/nature/journal/v502/n7470/full/nature12540.html

    The work:-
    The projected timing of climate departure from recent variability.
    Camilo Mora, Abby G. Frazier, et al
    University of Hawaii.

    ‘ Here we present a new index of the year when the projected mean climate of a given location moves to a state continuously outside the bounds of historical variability under alternative greenhouse gas emissions scenarios.’

    Dates like 2020 and 2047 occur often in the absence of effective mitigation scenarios.

    The implication is that the study identifies when the current historic maximum temperature at various locations becomes the minimum temperature experienced at that location.

    Every place I can live in my country has regular maximums over 30 degrees Celsius ‘historically’. Life where that becomes the minimum will not be livable, and nor will low-energy low-input agriculture.

    Not looking good.

  21. 221
  22. 222
    Ray Ladbury says:

    Patrick027 and Dave123,
    Yes, definitely satire–albeit perhaps too close to reality. Frankly, I don’t think the Koch bros. care whether they are right or not. They tend to view the world in terms of what they can impose on the rest of us rather than what is real and what is not. And yes, they are likely intelligent men. However, one can use intelligence to fool oneself as well as to realize the truth.

  23. 223
    Mal Adapted says:

    Ray Ladbury:

    Frankly, I don’t think the Koch bros. care whether they are right or not. They tend to view the world in terms of what they can impose on the rest of us rather than what is real and what is not. And yes, they are likely intelligent men. However, one can use intelligence to fool oneself as well as to realize the truth.

    I strongly suspect you’re right that they don’t care whether they are right or not. I’m pretty sure they’re both highly intelligent men (if I’m so smart, why aren’t I rich?).

    I don’t think they’re necessarily fooling themselves, either. They might be well aware that AGW is real, and that they’ve gotten rich by externalizing the climate costs of the way they got their money. By rational calculation, they may decide it’s cost-effective for them to ignore that.

    They may expect that (by the definition of externality) their climate costs will mostly be paid by other people, while their wealth will insulate them from the consequences of AGW. After all, when you’re that wealthy, you can choose where you want to live, you can afford to pay a little more for food, you can hire bodyguards, and on and on. ‘Twas ever thus!

    Once again, “stupidity” (or self-deception) isn’t always the least hypothesis.

  24. 224
    sidd says:

    I have been staring at Reichstein(2013) for a while

    doi:10.1038/nature12350

    (seems to be freely available thru a search at scholar.google.com)

    especially Fig 3c. That figure exhibits remarkable power law distribution of the probability of a given size of loss of primary production in response to climate stress in temperature or precipitation across 5 continents and Oceania over four orders of magnitude.

    This graph seems to be saying something important about the global uniformity of the size distribution of fluctuations in the response of ecosystems to climate stressors. I am impressed by the power law behaviour across three or four orders of magnitude (but perhaps there is a slight droop at the very large magnitude events)

    1)A priori, would one expect power law behaviour? I know one sees it all over the place, but I mean, is there a physical argument for this be so ?

    2)Why would the exponent be the same globally, over very different ecosystems and climate regimes ?

    sidd

  25. 225
    Jim Larsen says:

    Here’s an article about the shutdown’s effect on Antarctic research.

    “Tragic”.

    http://www.nytimes.com/2013/10/15/us/an-american-shutdown-reaches-the-earths-end.html?src=recg

  26. 226
    Walter Manny says:

    To the so-called pause, from the IPPC draft, for others to comment on:

    “There is very high confidence that models reproduce the general features of the global and annual mean surface temperature changes over the historical period, including the warming in the second half of the 20th century and the cooling immediately following large volcanic eruptions. Most simulations of the historical period do not reproduce the observed reduction in global-mean surface warming trend over the last 10–15 years. There is medium confidence that the trend difference between models and observations during 1998–2012 is to a substantial degree caused by internal variability, with possible contributions from forcing inadequacies in models and some models overestimating the response to increasing greenhouse-gas forcing. Most, though not all, models overestimate the observed warming trend in the tropical troposphere over the last 30 years, and tend to underestimate the long-term lower-stratospheric cooling trend.”

    Reference:

    http://www.climatechange2013.org/images/uploads/WGIAR5_WGI-12Doc2b_FinalDraft_TechnicalSummary.pdf

  27. 227
    Ray Ladbury says:

    Walter,
    Good to see you. A question–since we are still seeing temperatures rise throughout the depth of the ocean, even down to 2000 meters, and given that the oceans constitute over 98% of the thermal mass of the climate system, does that not imply that an energy imbalance persists?

  28. 228
    Walter Manny says:

    Hi, Ray,

    I’m not here to comment, simply to ask questions and let those those who actually know what they’re talking about comment as they wish, as you have with your own rhetorical question, and thanks. Also from the IPPC draft, perhaps more to the point, perhaps not:

    “The observed reduction in surface warming trend over the period 1998–2012 as compared to the period 1951–2012, is due in roughly equal measure to a reduced trend in radiative forcing and a cooling contribution from internal variability, which includes a possible redistribution of heat within the ocean (medium confidence). The reduced trend in radiative forcing is primarily due to volcanic eruptions and the timing of the downward phase of the 11-year solar cycle. However, there is low confidence in quantifying the role of changes in radiative forcing in causing the reduced warming trend. There is medium confidence that internal decadal variability causes to a substantial degree the difference between observations and the simulations; the latter are not expected to reproduce the timing of internal variability. There may also be a contribution from forcing inadequacies and, in some models, an overestimate of the response to increasing greenhouse gas and other anthropogenic forcing (dominated by the effects of aerosols).”

    Reference:

    http://www.climatechange2013.org/images/uploads/WGIAR5-SPM_Approved27Sep2013.pdf

  29. 229
  30. 230
    AIC says:

    Ray @ 200, Mal Adapted @ 223 :

    I’m thinking that the Koch brothers see that there will eventually be regulation (hopefully, prohibition) of fossil fuel CO2 emissions, and are using their oil money to diversify, buying non oil companies, like Georgia Pacific lumber and Invista fabrics (spandex, anybody?). http://www.kochind.com/Companies/ shows quite a long list. In the meantime, they are working to keep the money coming in for as long as possible, like all the other fossil fuel companies.

  31. 231
    AIC says:

    Has anybody tried working with this outfit?
    Help A Reporter Out

    http://www.helpareporter.com/

  32. 232
    Ray Ladbury says:

    Walter,
    Have you looked at the Skepticalscience Escalator? This makes it pretty clear that surface warming takes place in bursts. The Heartland Idjits have unwittingly done the same thing with their latest missive.

    This is in and of itself interesting, as so-called internal variability is one of the least understood aspects of climate change. The recent work on the role of the deep oceans is particularly illuminating in this regard. To me, it says that the equilibration time may be substantially longer than had been assumed by some. That has some important implications for climate sensitivity. I don’t know if you caught my discussion earlier this month of a study I did (while on an unexpected and unasked for 2-week vacation) on climate sensitivity estimates. The distribution is now pretty clearly bimodal, with one mode around 2.16 degrees per doubling and the other at around 3.64 degrees per doubling. I think this is a result of different assumed equilibration times for the studies–short times producing low estimates and longer times producing the higher mode.

    What this means is that we may warm more slowly, but the warming “in the pipeline” will be a bitch. Hope you have a good crop of students this year.

  33. 233

    #228–And the question was what, exactly?

  34. 234

    #232–Ray, I for one did not catch that discussion. I’d be interested to read more about it, though; do you have a pointer for us?

  35. 235
    stranger says:

    Concerning the articles I’ve read today on mosses determining that Arctic temperatures now are the highest they’ve been in 44K years. I was told that you can’t carbon date the moss. When the moss died it would have stopped generating C-14. There is no way to differentiate between dead moss and dead moss covered by ice. So the researchers can say they have “old” dead moss but they can’t say anything about ice unless they can prove that without the ice the moss would have mysteriously come back to life and the C-14 started accumulating again.

    I know nothing of how carbon dating works on moss. An explanation would be appreciated.

  36. 236
    Walter Manny says:

    Ray, I did see that a while back, though I can’t recall what took me there as I don’t read that blog generally. Trenberth also talked about a ‘staircase’ in his NPR interview — I assume the same idea, that we have cold natural variability cancelling out artificial heat and will soon have hot on top of hot, so to speak? Has this theory arrived too late for AR-5, or has it been addressed in there somewhere? I’m reading it in pieces.

    And I’ll have a peek at what I assume will become known as the Ladbury Furlough Study tomorrow.

  37. 237
    Walter Manny says:

    Kevin,

    Sorry, not clear — I was referring to #210. #226/8 would be a follow-on reference, topical I hope, from the IPPC. I should have asked if RC was planning to do an update in light of AR-5′s discussion of the hiatus.

  38. 238
    Hank Roberts says:


    MEAGHAN CARPENTER A Slow Catastrophe

    2010
    … ephemera, collected plastic bags, balloons, science beaker with water and gravity

    A Slow Catastrophe is a shrine that comment’s on the slow but catastrophic degradation of our natural environment …. After a few days the balloons slowly deflate and float to the floor literally collapsing the piece ….

    Artist understands and conveys rate of change and eventual consequences. Nice piece, for those who like this sort of thing.

  39. 239
    Ray Ladbury says:

    Kevin and Walter, I made reference to what I found in the 6th comment of this month’s Unforced Variations (I get bored doing nothing pretty quickly).

    It is not much of a “study”. I was just curious why the AR5 did not identify a “best” value for sensitivity and looked over the estimates given on the AGWObserver page on climate sensitivity estimates. There’s a clear bimodality, and remembering back to efforts by Schwarz and Lindzen, I speculated that assumed equilibration time might have something to do with the differences.

  40. 240
    Walter Manny says:

    Ray, thanks for the pointer, and I’m not sure what to make of it. What is the overarching significance, do you think (or could you restate), of the bifurcation you have identified? I assume not that there are two climate sensitivities that take it in turns somehow, that there are two sets of physical phenomena somehow at work? Sorry, only one cup of coffee into the day…

  41. 241
    MARodger says:

    Stranger @235.
    I’m pretty sure carbon dating moss is not much different in principle to any other carbon dating which relies on the 5,730 year half-life of carbon-14. Thus the 44,000 year result is at the point where C-14 has almost gone. Therefore the upper age of the sample could then be even older and stretch back to the Eemian interglacial 120,000 years ago, a more sensible result than 44,000 years which would place it well into to last ice age.

    Of course Cap’n Watts, Lord Denier of Wattsupia, is highly sceptical of these Baffin Island results, saying there is a “logical failure in the claim being made.” (And the good Cap’n has a lot of experience of claims that later fail due to his illogical thinking.). He suggests the ice could have ‘melted’ due to sublimation and since been re-covered but this is crackpot thinking as the thesis is solely that it has not been warm enough to melt the Baffin Island ice fields over the +44,000 years. If there had been melting due to temperatures above freezing, the moss would re-colonise the ground, but that hasn’t happened.
    His second take is that the result only applies to a bit of Baffin Island and is not representative of the Arctic. Yet this does not detract from the claim that today’s Baffin Island ice cap temperatures are unprecedented over at least 44,000 years – although with the time period not mentioned in the paper’s title, the good Cap’n tells us it cannot be “unprecedented” as the now-dead moss has to have grown at some point in the past and that requires today’s high temperatures. (Myself, I think the good Cap’n has been spending too much time with Peter Pan and his chums.)
    And as he makes an appended admission that today’s receding ice is due to high temperatures, the good Cap’n proposes this could be due to decreasing albedo due to soot, something the naughty researchers failed to mention, apparently. The coverage here suggests the researchers do consider GHGs are the “likely culprit” although the actual quote of lead author Gifford Miller is “Natural variability can’t be the main contributor.” This of course is the basic take on the research being bounced around the media and is something the poor Cap’n Watts appears at a loss to explain properly.

  42. 242
    Ray Ladbury says:

    Walter, bimodality is usually an indication that one is sampling from two different parent distributions. One way this could happen is if you have a system with multiple equilibration times. Tamino discussed this with his two-box model, where he had a 1-year time for the atmosphere and a 30-year time for the ocean. It could be that the 30-year time should be longer or that there is a third box with a longer constant.

    Both Schwarz and Lindzen managed to get very low sensitivities in part by assuming rapid equilibration of the climate. The recent results that show more mixing into the deep ocean than thought support a longer equilibration time as well as explaining the escalator structure. The article I cited also seems to bear this out.

  43. 243
    L Hamilton says:

    @stranger #235

    In their paper the authors explain how they know that some of the ancient plants they analyze must have been must have been continuously ice-covered for at least 44,000 years. If the plants had died without becoming ice covered they would rapidly erode or be re-colonized by new plants.

    “Our field observations, and the presence of extensive vegetation-free regions surrounding most retreating ice caps [Locke and Locke, 1976] indicate that most long-dead tundra plants exposed by ice recession are rapidly removed from the landscape by wind-blown winter snow or by run-off during the melt season. Re-colonization may begin within a few years of exposure, and the few moss clumps that escape rapid erosion commonly regrow [Yashina et al., 2012; La Farge et al., 2013].”

  44. 244
    Walter Manny says:

    Ray, thanks, helpful. Here’s another question, if you’re willing to have at it.

    I can’t be the first to ask, but I’m trying to get my head back into the game, and I’m wondering if it’s possible to fit all the [necessarily] complex models into a bigger, cruder one, at least to help illustrate on a large scale. Granted the greenhouse effect does not exactly mimic a greenhouse, is it in any way analogous to think of the earth as an insulated system and excess CO2 as extra insulation, such that it there is a exit delay, so to speak, a “cooling delay” and thereby overall warming as a result? If so — I expect such a simplistic is no good, but what the heck — would there not also be an entry delay? Please forgive the grade-school nature of the question and, if possible, point me in the appropriate direction.

  45. 245
    Nigel Williams says:

    http://www.nature.com/nature/journal/v502/n7470/full/nature12540.html

    OK, now I’ve read the paper the data gives:

    Figure 2 | The projected timing of climate departure from recent variability. a, b, Projected year when annual (a) or monthly (b) air temperature means move to a state continuously outside annual or monthly historical bounds, respectively…’

    They observe:-
    ‘It is remarkable, however, that after 2050 most tropical regions will have every subsequent month outside of their historical range of variability (Fig. 2b). Although this is later than the yearly averages, we stress that this is an extreme situation, in which every month will be an extreme climatic record.

    Rite.

  46. 246
    Hank Roberts says:

    > would there not also be an entry delay

    Wait, what do you teach, at what level?

    How complicated would you like that answer to be? Suggestions:

    Words:

    Joseph Fourier in the 1820s …. energy in the form of visible light from the Sun easily penetrates the atmosphere to reach the surface and heat it up, but heat cannot so easily escape back into space.

    Numbers:

    The Earth’s atmosphere is effectively transparent to solar radiation between .34 and .7 microns. Consequently 22.5 percent of incoming solar radiation goes directly to the surface of the Earth and is absorbed.

    Picture

  47. 247
    Anonymous Coward says:

    Walter Manny wrote: “is it in any way analogous to think of the earth as an insulated system and excess CO2 as extra insulation, such that it there is a exit delay, so to speak, a “cooling delay” and thereby overall warming as a result?”
    I’d say so.
    There is a difference however: insulation typically works because there are heat sources in the insulated space. CO2 on the other hand causes warming because…
    “would there not also be an entry delay”
    … there is a massive asymmetry. Exit is delayed much more than entry because of the different radiating temperatures and therefore wavelengths. And that is main cause of the warming rather than internal heat sources (which also exist of course).

    Just in case that’s what you had in mind: the delay between CO2 emissions and warming is not caused by your “entry delay” (which mainly affects the equilibrium temperature) but rather by what might be called thermal inertia.

    “if possible, point me in the appropriate direction”
    Watch the relevant parts of a course like David Archer’s.

  48. 248
    stranger says:

    Thanks LHamilton and MARogers, your information is quite helpful.

  49. 249
    Ray Ladbury says:

    Walter,
    The simplistic model I use is that you start with a climate system in thermal equilibrium. All energy into the system comes from the Sun. All energy leaving the system is in the form of thermal radiation–long-wave IR (LWIR). At equilibrium, energy in equals energy out. Now you block some of the energy leaving–it doesn’t matter how, but for ghgs you take a big bite out of the spectrum of outgoing LWIR. Since energy in is now greater than energy out, the temperature of the system must rise. In particular the temperature at the top of atmosphere must rise, since this determines the spectrum and amount of LWIR emitted. The TOA temperature must rise until the energy in the outgoing LWIR spectrum again equals the incoming energy. Whatever goes on below TOA is secondary. Energy may heat up the deep oceans–that doesn’t affect outgoing LWIR. Energy may cause storms–that also doesn’t, to first order affect outgoing LWIR. You can have changes in albedo–they only affect outgoing LWIR inasmuch as they ultimately affect energy in and TOA temperature. So, ultimately, the sensitivity is determined by how much surface temperature must rise to restore equilibrium at TOA.

    I don’t know if that helps or not.

  50. 250
    Walter Manny says:

    Thanks, Ray et al, for your response and your patience. I’ve not been thinking at all about this stuff for a while, it’s easy on the way back in to get bogged down in the more “entertaining” aspects of the back-and-forth surrounding it, so time for me to hit the reset button, thus the annoyingly 101 nature of my questions.

    Three others, then, the first trivial, I suspect: Since we can see the Earth from space, I assume some energy escapes the planet as reflected light. Is it negligible relative to the LWIR or part of it?

    Is it a logical consequence of the simple model that holding CO2 where it is would give us a new [hotter] equilibrium?

    Finally, though this one is too big, I think, which of the working hiatus theories (in addition to deep ocean) do you believes merits more consideration (e.g. reduced atmospheric water vapor)?


Switch to our mobile site