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  1. Good chance that this will be picked up by the next NIPCC report; they love hypothetical feedbacks (if they can somehow portray them as a negative feedback, eg the sheep getting smaller but fatter, so their effective surface area for reflecting sunlight increases).

    Comment by Bart Verheggen — 7 Jul 2009 @ 9:00 AM

  2. How do weights at birth compare in the desert vs in Scandinavia? It is easy to conduct an experiment taking sheep to where the weather never drops below freezing and the highs hit over 100. I have raised sheep and find city folks have a lot of notions about them.

    Comment by Henry chance — 7 Jul 2009 @ 9:04 AM

  3. That’s just baaad science! This blog is supposed to give us genuine well-researched science: I feel like I’ve been fleeced!

    Comment by Chas — 7 Jul 2009 @ 9:40 AM

  4. I’m sure this a cyclical variation, and that the poor new year’s lambs merely get worked harder during the years when their youth is spent working hard on a climate book. The current generation’s weight loss means another book is likely in the works, that’s all.

    Check the weight records back a ways and I’m sure the association with their book production will be clear:

    “Climate: present, past and future” by HH Lamb – 1977

    “Weather, climate & human affairs: a book of essays and other papers” — HH Lamb – 1988

    “Climate, history and the modern world” – HH Lamb – 1995

    Comment by Hank Roberts — 7 Jul 2009 @ 9:47 AM

  5. Does this post imply that Real Climate has become more sheepish?

    Comment by D. Trent — 7 Jul 2009 @ 10:06 AM

  6. Suppose sheep are half the original mass. Their individual reflecting surface would then be reduced so you would need 2^(2/3) sheep to reflect the same amount of sunlight. While that is more sheep numerically (by a factor of 1.6) it is less sheep by mass (by a factor of 0.8) so that fewer resources are needed to get the same result.

    While this feedback appears to be negative, one should not ignore the possibility of a heard mentality with a larger number of smaller sheep. Should they all turn together to the dark side and become black sheep, trying to get back to the “three-bags-full” standard of prior generations, one could hit a runaway tipping point that could be catastrophic.

    This situation requires close monitoring, perhaps by requiring the sheep to follow Mary to school each day, something that may require an even greater change to the rules that make up our way of life than ending the use of coal for power generation. In short, our way of life is threatened by spherical sheep.

    Comment by Chris Dudley — 7 Jul 2009 @ 10:10 AM

  7. Isn’t the decreased sheep albedo effect offset by a decline in methane production with smaller sheep?

    Also how has global warming affected the global demand for wool? Maybe an economist could whey in?

    Comment by Soil Creep — 7 Jul 2009 @ 10:14 AM

  8. Aren’t you aware that sheep-measuring stations are far too often located right next to restaurants which serve lamb kebobs? That they’re often placed right next to barbecue grills? That the vast majority of observing stations don’t meet the siting recommendations set by the international sheep-weighing network?

    Living too near heavily developed areas causes sheep to lose weight from the stress of urban life, and from watching too many diet programs on “Oprah.” The apparent decline in sheep weight is merely a reflection of the “urban sheep island” effect.

    Comment by tamino — 7 Jul 2009 @ 10:26 AM

  9. Since I’m guessing that sheep shorn of their coat produce a higher albedo, are wool clothes the newest tool against warming?

    Comment by Dean — 7 Jul 2009 @ 10:26 AM

  10. What happens if the sheep eat the daisies?

    Comment by Tom Barker — 7 Jul 2009 @ 10:37 AM

  11. Lets remember the sad and epic tail of “The Tragedy of the Commons” by Garrett Hardin. It is the story of an heroic herd that meats its demise. These ruminates lead by humans acting in their own self interests – ultimately destroyed their shared limited resource. Hardin tells of the industrious herders sharing a common parcel of land (the commons), which is open to free grazing. Tragedy strikes despite all the herdsmen agreeing that they must not let it happen.

    Harding wrote of cows, but it applies to sheep:

    “In Hardin’s view, it is in each herder’s interest to put as many cows as possible onto the land, even if the commons are damaged as a result. The herder receives all of the benefits from the additional cows, while the damage to the commons is shared by the entire group. If all herders make this individually rational decision, however, the commons are destroyed and all herders suffer.”

    Shortly after follows the story of the Braised Lamb Shanks with caramelized onions.

    Comment by Richard Pauli — 7 Jul 2009 @ 11:10 AM

  12. Hmmmm….Maybe repainting all of the black cars, white? And how ’bout those new ‘white asphalt’ shingles for the roof – why, next to those Japanese PV Tiles!!!
    GM Lightning Bugs to cut down on Street Lighting?
    And can’t you just see the ‘Climate Solution Found’ headlines that proclaim the unexpected “Global Cooling” windfall produced by the GM ‘upside-down leafed’ Japanese Maple albedo affect?

    Comment by James Staples — 7 Jul 2009 @ 11:13 AM

  13. You did it again! Suckered me into thinking (not long — I fell off the turnip wagon long ago) you were serious.

    How long until some pundit picks this up and runs with it?


    Comment by John (Burgy) Burgeson — 7 Jul 2009 @ 11:25 AM

  14. This is all extraneous stuff that distracts from important discussions of whether or not warming impacts the number of times an unladen swallow needs to beat its wings to maintain air-speed velocity.

    If you weren’t so afraid of real climate discussions, Gavin, you would be aware that studies on this matter clearly demonstrate that warming is not happening and if it is, then it is not possibly impacted by the GHGs that algore emits.

    Comment by FM — 7 Jul 2009 @ 11:45 AM

  15. #9 Dean:

    Yes but you don’t get a color choice. White only. Also, you can’t go inside when the sun is shining.

    Comment by Doug Bostrom — 7 Jul 2009 @ 12:33 PM

  16. How ’bout outlawing dark cows to offset their methane impact, or will then only outlaws have dark cows? James Staples does have a point about roofing—I was looking for 3 tab shingles, hoping to find some with greater then 80% ir reflectivity. No such luck. …and isn’t there a way to put a reflective agent into blacktop that would migrate to the surface to reflect? The McDonald near my house blacktopped their concrete parking lot; increasing the air temp around it by at least 20º

    Comment by Eliot — 7 Jul 2009 @ 1:06 PM

  17. That would be a amplifying effect in general, but the actual population of sheep concerned come in many colours, so the overall affect is uncertain.

    “Affect?” Hah! You backsliding “luke-coolers” are almost as linguistically challenged as we “hard-as-ice coolers” (not to be confused with “whine coolers”).

    Please show a detailed chart of this “uncertain” effect (or “affect” or whatever) over at least the last six months.

    I also demand that you immediately provide all code (that you have ever written) and all data (that you have ever seen), as well as library borrowing records, emails to shepherds and other incriminating evidence to be determined. The ridiculous assertion that the amplification of sheep albedo cooling is “uncertain” flies in the face of the plain evidence from the “Little Sheep Age”.

    I have recently discovered a mysterious directory entitled “Black Sheep” on a laptop abandoned in a landfill in Pennsylvania and I hereby demand an immediate congressional inquiry into the entire matter.

    [Response: Ah, yes. That was an experiment where the sheep were all shorn before the analysis was performed. Hansel van Crane has done some extensive GCM analyses using the “REVERBERATE-H” climate model which shows it makes no difference. They found this to be true both for their “JOHNNY” simulation where the GCM was accidentally initialized with Precambrian stratospheric ozone concentrations, and the “RUFUS” simulation wherein the initialization error was subsequently fixed. – mike]

    Note also that the “shepherd’s crook” comes in several shapes. I will be breaking at least one of them, but I have yet to decide which one.

    Comment by Deep Climate — 7 Jul 2009 @ 1:46 PM

  18. Any word on if the sheep get yummier when they are smaller. This could offset any negative effects from AGW.

    Comment by MarkusR — 7 Jul 2009 @ 1:48 PM

  19. “This could offset any negative effects from AGW.”

    Lamb gives me gas.

    So, no, maybe not…

    Comment by Mark — 7 Jul 2009 @ 2:05 PM

  20. re 14 : African or European, your swallow?

    Comment by François Marchand — 7 Jul 2009 @ 2:30 PM

  21. “re 14 : African or European, your swallow?”

    I don’t know.


    Poor old Galahad should have stayed in the Castle…

    Comment by Mark — 7 Jul 2009 @ 2:38 PM

  22. > 3-tab … 80% reflectance

    All I found was
    which is current good info, invites comments, and has a comprehensive definitions page that will make sense of the numbers:

    But this doesn’t have the numbers for my ideal, a green-and-white rooftop, covered with low-growing plants mowed by a very small herd of tiny white sheep.

    We’ll need sheep bridges down the block so the herd can be moved regularly from one roof to the next, folowing best practice:

    Comment by Hank Roberts — 7 Jul 2009 @ 3:36 PM

  23. Has this hypothesis been run by Harold (the clever sheep)? or is he still trying to work out how to fly?

    Comment by David — 7 Jul 2009 @ 3:42 PM

  24. I heard on Rush that Al Gore doesn’t have a single white sheep on his property! Not one! Commie pinko hypocrite!

    Comment by dko — 7 Jul 2009 @ 3:45 PM

  25. As Ebenezer Scrooge might say “Baaa Humbug!”

    Comment by Lawrence Brown — 7 Jul 2009 @ 3:45 PM

  26. We’ll need sheep bridges down the block so the herd can be moved regularly from one roof to the next, folowing best practice:

    Maybe the miniature sheep can be bred with wild mountain sheep that can jump from roof to roof while the insomniacs try to fall asleep by counting them…

    Comment by Fred Magyar — 7 Jul 2009 @ 3:57 PM

  27. #3, I think you made a minor mistake:

    That’s just baaad science! This blog is supposed to give us genuinedyed-in-the-wool well-researched science: I feel like I’ve been fleeced!

    Comment by Douglas McClean — 7 Jul 2009 @ 4:00 PM

  28. An increase in black sheep (a la melanic moths in the industrial north of England in the Industrial Revolution) might mean we had greenhouse sheep, absorbing UV and re-emitting it at longer wavelengths.

    Markus R: nah. You need to give tham a few months. Spring lamb is yak compared to yearlings.

    This kind of post just rams it home to ewe how complex this whole OGW (Ovineogenic Global Warming) thing is.

    Comment by Peter Mc — 7 Jul 2009 @ 4:09 PM

  29. Apparently RealClimate (and Al Goat) is ignorant to the fact that we can already see the Earth from space, meaning that it reflects light, which means that reflected light comes BEFORE sheep. Since sheep LAG reflected light (by maybe 800 years or so) it’s obvious that sheep can’t influence the surface albedo.

    [Response: Equally problematic is the fact that this article ignores the compelling recent evidence provided for a new natural pattern of climate variability, unrelated to global warming, but instead related to the AMO, NAO, and PDO (the so-called “Ei-EIO”) that appears mostly, if not entirely, responsible for the observed changes in livestock characteristics (see McDonald, O., Reconstruction of the Ei-EIO from Bovine Organic Deposits, J. Bull. S., 42, 2009). -mike]

    There’s more problems. Recent blogs, Watts up with the livestock, and Ovine audit have determined that large issues exist with the sheep number data, usually photos are taken too close to fences, among other more obvious problems outlined by tamino in #8.

    Comment by Chris Colose — 7 Jul 2009 @ 4:24 PM

  30. The trend since 2008 is toward sheep with a larger carbon footprint:

    Comment by dko — 7 Jul 2009 @ 4:53 PM

  31. Yes, good stuff Gavin, and great comments. But seriously folks, whether or not the actual example (smaller Soay sheep) is correct or not (and I have some doubts), it is a reminder that as well as seriously affecting populations of wild animals, climate change is going to have consequences for domesticated animals. And consequences which are going to often be unpredictable and counter-intuitive, and affect, in turn, the nature of agriculture around the world.

    Comment by David Horton — 7 Jul 2009 @ 5:07 PM

  32. Way to go David. May your wet blanket be made of shrinking wool.

    Comment by Joel — 7 Jul 2009 @ 8:01 PM

  33. Bad news.

    It’s not just sheep.

    Comment by Hank Roberts — 7 Jul 2009 @ 8:10 PM

  34. wont take this line of argument seriously until land cropped by sheep and land strewn with sheep dung have had irrefutable measurements of their albedo.

    in my town, neighbors have hired goats to clear roadside margins of grass, weeds and poison ivy that mowers can not be bothered to clear…the matted remnants of vegetation are much darker than what was there when the goats were penned in to munch the weeds.

    Comment by greensmile — 7 Jul 2009 @ 8:12 PM

  35. Gavin, you are being unkind to our dumb, woolly friends, who have no ability to reply. Criticism is better directed at more articulate bleaters such as Vaclav Klaus, President of the Czech Republic, who is on record complaining about the “scientific consensus on global warming”. Used to the dialectic of social sciences, Klausian sheep rail against the immutable laws of nature.
    I have herd that the Heritage Foundation folks are to rename their annual get together as a “Muster of the Faithful”. Sheep farmers in my neighbourhood are being asked to retrain their Border Collies to round up people rather than quadrupeds.
    And I recently met a chap, Carl Marks, who is working on a book, using Hegelian analytic tools, that ends with: “Climate Denialists of the world unite, you have nothing to lose but your reputations.”
    p.m. Carterton, New Zealand.

    Comment by Patrick McLean — 7 Jul 2009 @ 8:31 PM

  36. Why is everyone making fun of a genuine peer-reviewed climate science paper published in the journal Science.

    Comment by John Lang — 7 Jul 2009 @ 8:35 PM

  37. Mike (29):

    And let’s not forget recent reports with respect to Shiitake mushroom culture and propagation, in particular:

    Fieces, I. M. (2008). Albedo effects of shiitake mushrooms in General Circulation Models: theory and observations. Bull. Shiit. Cult. & Prop. 456:1072-1091.

    Among others.

    Comment by Jim Bouldin — 7 Jul 2009 @ 8:41 PM

  38. Where’s the Denial Depot when you need it?

    Comment by Jim Bouldin — 7 Jul 2009 @ 8:48 PM

  39. Stephen Chew has said that breeding bunnies is more efficient (and fun) than the uneconomical lamb.

    Comment by Eli Rabett — 7 Jul 2009 @ 8:48 PM


    Someone had to add this.

    Comment by Ed — 7 Jul 2009 @ 9:38 PM

  41. #32 Joel – it wasn’t a blanket condemnation!

    Comment by David Horton — 7 Jul 2009 @ 9:42 PM

  42. Ed, the problem is you need to get those sheep airborne

    Comment by Jim Bouldin — 7 Jul 2009 @ 10:12 PM

  43. > airborne

    The metaphor, it burns:

    “… a bellwether in the fledgling global economy….”

    Comment by Hank Roberts — 7 Jul 2009 @ 10:31 PM

  44. Bleating loses as global warming shrinks sheep.

    Comment by Howard S. — 7 Jul 2009 @ 10:58 PM

  45. How about if the sheep are finally grasping economics and are decreasing in size to increase their lambs’ ribs value in meat markets?

    Comment by jyyh — 7 Jul 2009 @ 10:58 PM

  46. But surely we can engineer a solution to falling sheep albedo!

    But we have to be careful that we don’t make things worse, eg. breeding white cows wouldn’t be a good idea due to increased methane production and the use of land.

    Alternatively, maybe we can create a balance between white and black sheep and carefully change the balance to create a stable temperature.
    However this might not be possible due to market fashions for wool. Unless black wool can be bleached and dyed??

    Comment by Paul — 8 Jul 2009 @ 2:08 AM

  47. Mutton anyone?

    Comment by Paul — 8 Jul 2009 @ 2:10 AM

  48. I have some questions concerning climate change:

    I’ve been reading some on temperature analysis being done by various people and institutions. One area of interest has been the number of weather stations. I found a link at nasa: “” which showed the number of weather stations over a period of time. From the middle graph (the number of reporting stations as a function of time), there exists sharp rises and falls. It appears that there was more measurements taken from the years 1950 to about 1990 with a decline beginning around 1980.

    So my first question is: How exactly is this being handled? Obviously, some weather stations exist in warmer and colder climates. If you have a large number of stations being shutdown in warmer climates, would the trend not show colder figures?

    Are those stations that dropped off the grid during the 1990 sharp decline still being used to create the figures? What happens if you drop them off and use only the ones that are still currently active? Does the same trend still occur? To what degree?

    How good or bad is the quality control at the stations?

    Are orbits or sun activity taken into account in the temperatures?

    A lot of questions I know. =/

    Comment by EL — 8 Jul 2009 @ 2:28 AM

  49. I haven’t seen any sheep today. Therefore your so-called “theory” is wrong.

    Comment by Silk — 8 Jul 2009 @ 7:27 AM

  50. That proves it ! Global warming is a recent scam started by the music industry to make more money:

    Comment by Geoff Wexler — 8 Jul 2009 @ 8:39 AM

  51. I think we’ve definitely uncovered some more known unknowns here. The theories flying around our office include a spectacular debate about blondes vs brunettes.

    There’s so much potential for further research here. For example, what has been the impact on surface albedo during the summer months with Scouts and Guides moving away from green canvas ridge tents, to white bell tents?

    So many hypotheses, so little time…

    Comment by Vicky I — 8 Jul 2009 @ 8:52 AM

  52. Great. The wife already accuses me of wool gathering when I read this site.

    Comment by Jeffrey Davis — 8 Jul 2009 @ 10:32 AM

  53. I don’t know, this sounds like it could lead to the “wool ball” effect.”

    Comment by Lynn Vincentnathan — 8 Jul 2009 @ 12:26 PM

  54. If more sheep impact the albedo enough to cause a cooling effect, wouldn’t more solar panels (which absorb light–especially in high albedo deserts) cause a global warming impact.

    I did some really back of the envelope math on this before (e.g. Ast 101 level greenhouse effect model),and converting all of the u.s.’s electricity production to solar, and assuming all panels were placed in the desert, would cause a small, but significant increase in equilibrium temperature.

    Comment by Colin — 8 Jul 2009 @ 12:51 PM

  55. Does this have any chance of being considered in the cap and trade legislation? Could I maybe acquire a herd or three and sell credits?

    Comment by Bert Oleander — 8 Jul 2009 @ 3:00 PM

  56. Again, we are not taking a holistic approach on this. What about other species?? Like the Arctic wolf spider, which is getting bigger in a warming climate (at least the females) — see: (below)

    “Climate change and sexual size dimorphism in an Arctic spider”

    Abstract: Climate change is advancing the onset of the growing season and this is happening at a particularly fast rate in the High Arctic. However, in most species the relative fitness implications for males and females remain elusive. Here, we present data on 10 successive cohorts of the wolf spider Pardosa glac-ialis from Zackenberg in High-Arctic, northeast Greenland. We found marked inter-annual variation in adult body size (carapace width) and this variation was greater in females than in males. Earlier snowmelt during both years of its biennial maturation resulted in larger adult body sizes and a skew towards positive sexual size dimorphism (females bigger than males). These results illustrate the pervasive influence of climate on key life-history traits and indicate that male and female responses to climate should be investigated separately whenever possible.

    And they might be getting more numerous — see:

    This may mean a positive feedback, since they appear somewhat darker (than white snow or sheep), or at least they might cause an arctic amplification effect, and this might overwhelm the negative feedback of shrinking sheep.

    And we’re not talking arctic wolf spiders in sheep’s clothing.

    Comment by Lynn Vincentnathan — 8 Jul 2009 @ 3:20 PM

  57. Ah, it’s truly summer …

    Comment by Dr. Wil Burns — 8 Jul 2009 @ 5:47 PM

  58. Don’t you know that the Vikings had tiny sheep about 3 inches high when they colonised Greenland. Therefore it is impossible that sheep are getting any smaller today.

    Comment by Michael Hauber — 8 Jul 2009 @ 7:53 PM

  59. #48 EL

    What the sheep are you talking about?

    Okay, follow the links:

    Comment by John P. Reisman (OSS Foundation) — 9 Jul 2009 @ 1:39 AM

  60. #51 Vicky I

    “So many hypotheses, so little time…”

    I’m all for further study of both blondes and brunettes. This is an area of scientific interest.

    The examination of species differences and potentials regarding atmospheric/climate heating and cooling based on short and long term environmental changes combined with internal natural variation and external forcing could net important discoveries.

    Comment by John P. Reisman (OSS Foundation) — 9 Jul 2009 @ 2:47 AM

  61. EL writes:

    If you have a large number of stations being shutdown in warmer climates, would the trend not show colder figures?

    The average in a given grid square would remain about the same.

    Comment by Barton Paul Levenson — 9 Jul 2009 @ 6:14 AM

  62. Ha! And you people keep saying that wethers is not climate. ;-)

    To quote a popular SF franchise:

    The Master: “Woolly thinking, Doctor.”
    The Doctor: “Yes, but it feels so comfortable worn next to the skin.”

    Comment by Chris Winter — 9 Jul 2009 @ 10:25 AM

  63. Re: #48

    El, there is a new angle on this. A retraction is being published in the J. Irreprod. Results, Vol. 243, in press.

    Comment by Tenney Naumer — 10 Jul 2009 @ 5:54 PM

  64. The wool is being pulled over your eyes…

    Comment by David B. Benson — 10 Jul 2009 @ 7:20 PM

  65. Suggest that everyone paint their roofs white starting with the folks in North America.

    Comment by Spudder — 11 Jul 2009 @ 6:36 PM

  66. Great post–but from the title, I expected a serious treatment of the denialosphere’s latest. Of course, this was a lot more fun–even if it hardly qualifies as a “maunder minimum.”

    Comment by Kevin McKinney — 12 Jul 2009 @ 7:38 PM

  67. Apparently Norstrilian several-ton legless sheep will evolve from Australian sheep as the climate warms….

    Comment by jayskew — 13 Jul 2009 @ 3:43 PM

  68. Baaah!

    I _really_ miss the previous blog comment layout in which the FIRST THING at the top of each comment was the commenter’s name and timestamp.

    It used to look like this:
    # raypierre Says:
    28 April 2006 at 7:10 AM

    What’s at issue is not just a matter of making mistakes…..

    Comment by Hank Roberts — 17 Jul 2009 @ 11:21 AM

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