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The Sheep Albedo Feedback

Filed under: — raypierre @ 1 April 2007 - (Español)

The already-reeling "consensus" supposedly linking climate change to CO2 is about to receive its final coup-de-grace from a remarkable new result announced in a press conference today by Dr. Ewe Noh-Watt of the New Zealand Institute of Veterinary Climatology [1]. Noh-Watt and his co-workers, describing work funded by a generous grant from the Veterinary Climate Science Coalition, declared "We have seen the future of climate — and it is Sheep." Prof. Jean-Belliere Poisson d’Avril, star student of Claude Allegro Molto-Troppo (discoverer of the Tropposphere) reacted with the words, "Parbleu! C’est la meilleure chose depuis les baguettes tranchées!"

The hypothesis begins with the simple observation that most sheep are white, and therefore have a higher albedo than the land on which they typically graze (see figure below). This effect is confirmed by the recent Sheep Radiation Budget Experiment. The next step in the chain of logic is to note that the sheep population of New Zealand has plummeted in recent years. The resulting decrease in albedo leads to an increase in absorbed Solar radiation, thus warming the planet. The Sheep Albedo hypothesis draws some inspiration from the earlier work of Squeak and Diddlesworth [2] on the effect of the ptarmigan population on the energy balance of the Laurentide ice sheet. Noh-Watt hastens to emphasize that the two hypotheses are quite distinct, since the species of ptarmigan involved in the Squeak-Diddlesworth effect is now extinct.

The proof of the pudding is in the data, shown in the Figure below. Here, the Sheep Albedo Index is defined as the New Zealand Sheep population in each year, subtracted from the 2007 population. The index is defined that way because fewer sheep means lower albedo, and thus a positive radiative forcing. It can be seen that the recent warming can be explained entirely by the decline in the New Zealand sheep population, without any need to bring in any mysterious so-called "radiative forcing" from carbon dioxide, which doesn’t affect the sunlight (hardly) anyway — unlike Sheep Albedo. Some researchers have expressed surprise at the large effect from the relatively small radiative forcing attributable to New Zealand Sheep, or indeed to New Zealand as a whole. "This only shows the fallacy of the concept of Radiative Forcing, which is after all only a theory, not a fact," says Noh-Watt. "Evidently there are amplifying feedbacks at work which give the Sheep Albedo Index a disproportionate influence over climate."

"A real breakthrough was using the statistical technique pioneered by Frusen-Glädje and Haagendassen in their study of the solar-climate connection." said Noh-Watt "Just as in their case, to get a good match to the observed climate, we had to optimize our smoothing algorithm by smoothing some parts of the sheep record more than others, and then rescaling the results." The optimized smoothing was applied to the years 1975-1991. Noted skeptic Rasmus Benestad has criticized this technique as meaningless curve-bashing (see footnote [3] below), but according to Noh-Watt, " All these guys are interested in is getting rich by riding their bicycles to work and selling carbon credits to the EU."

Not everybody agrees with the Sheep Albedo Hypothesis. Leading the flock of skeptics is the New Zealand Sheep Farmers Guild. Their spokesman, Steve Ramsturf (no relation) was quoted as saying "Baaah, Humbug. No matter what goes wrong with the world, they’re always trying to blame the poor New Zealand Sheep Farmer. First it was the methane belch tax. Now this Albedo thing. "

The recognition of the role of sheep albedo opens up some fascinating new possibilities for climate change mechanisms. There is in fact an important destabilizing feedback in the system: as climate gets warmer, there is less demand for wool sweaters and wooly underwear. Hence the sheep population tends to drop, leading to even more warming. In an extreme form, this can lead to a "runaway sheep-albedo feedback," which is believed to have led to the present torrid climate of Venus. Most researchers do not think this could happen on Earth, though. In fact, Oprah and Averell Chanteur, authors of the popular "Unstoppable" series (soon to be a major motion picture) say that the warming will usher in a new era of peace and prosperity, with less enslavement of domestic wool-bearing animals. The hypothesis is laid out in their forthcoming book, "Unstoppable Sheep, every five or six days," which expands on earlier popular titles in the series, such as "Unstoppable daylight, every 42 hours," "Unstoppable Summer, every 17 months, " and the ever-popular autobiographical work "Unstoppable nonsense, every two or three years."

However, Dirk Blitzen, noted researcher from Hogwartz Institute of Technology, has proposed an additional wrinkle on the sheep-albedo idea, which he calls the "sheep-Iris effect" (see Dasher et al. [4] for details). According to Blitzen, a reanalysis of Landsat images shows that as the climate gets warmer, sheep tend to huddle together less. Since wool has a lower emissivity than bare ground, the lack of huddling allows more infrared emission to escape from the ground, cooling the planet and stabilizing its climate. "Frankly, I don’t see how the climate can change much at all," stated Blitzen in recent testimony before the House of Lords, "To be honest, at this point I have a little trouble figuring out how there can even be summer and winter. In the end, I think it will turn out to be a problem with the data." Ozark Junior College satellite expert Jhon Chrystal agrees; his new analysis of MSU satellite data in fact casts doubt on the "consensus" that summer and winter have different temperatures.

But the sheep story may not be as simple as it seems. Hendreck Svampmark of the Danish Institute for Solar-Sheep Interactions notes that at the same time the number of sheep has been going down, the number of cows (which have a lower albedo than sheep) has been going up. "We believe that what is really behind it all are Galactic Cowsmic Rays, which are transmuting sheep DNA into cow DNA." Svampmark hypothesizes a currently undetected particle flux, which he calls "Cowsmic," because there is no observed trend in any of the better-known components of the Galactic Cosmic Ray flux. "We are trying to get money to put sheep in dark-matter accelerators to test our hypothesis, but there’s a hold-up with PETA. It’s all a big conspiracy to protect the consensus, I say."


[1] Noh-Watt, Ewe "Sheep-Albedo Feedback: A paradigm shift for climate change science." To be submitted to Readers’ Digest, "Humor in Uniform" section.

[2] Squeak, P.P. & Diddlesworth, I.R. 1987. The influence of ptarmigan population dynamics on the thermal regime of the Laurentide Ice Sheet : the surface boundary condition. In eds Edwin D. Waddington & Joseph S. Walder, The Physical Basis of Ice Sheet Modelling (Proceedings of a symposium held during the XIX Assembly of the International Union of Geodesy and Geophysics at Vancouver, August 1987), p.381-384.

[3] Benestad, a well-known spoilsport, points out that without the "optimized" smoothing out of the sheep-albedo-dip in the 1970′s, the correlation breaks down; it breaks down further if one looks at the pre-1966 record. His unprocessed version of the data is shown below:

[4] Dasher ON., Dantzer ON, Prantzer ON, Vixen ON, Comet ON, Cupid ON Donner . , and Blitzen, D.R , (2007) "Why does Rudolf’s nose glow so bright? Infrared effects of mammalian herd behavior." Bull. Tromsø Inst. Reindeer Husbandry

206 Responses to “The Sheep Albedo Feedback”

  1. 201
    James says:

    Re #200: Nor could I find any information on numbers of unowned cattle: estimates of overall cow popultation (up to 400 million), antecdotal accounts of programs to remove such cows from cities, and so on, but no good numbers.

    Still, my point (which I think your linked article supports) was about societial attitudes, not about the practicalities.

  2. 202
    Geoff Russell says:

    Regarding all the cattle posts — since I posted the first one!

    Cattle in many parts of the world work for a living and to replace them
    would most likely cost far more in carbon emissions than the cattle
    produce methane. You have to build and fuel tractors etc.
    But the cattle/sheep that people eat in Australia/Brazil/US/Europe etc
    produce prodigious methane quantities, plenty of carbon emissions during
    processing, and in many countries, are the driving force behind deforestation
    and loss of biodiversity. Our Australian Greenhouse Office in the

    puts the emissions for beef at 51.7 tonnes of emissions per tonne of
    beef (carcase). Aluminium, by comparison produces 20 tonnes/tonne.
    Wheat comes in at 0.4 tonnes/tonne.

    Drive an SUV (we call them 4WD) on a round trip of 10kms to the shops.
    You will produce about 3kg of emissions — but if you buy
    1kg of beef, that’s another 50kg of emissions (well its actually quite a bit more
    because the 50kg related to carcase, not all of which is eaten).

    The SUV construction emissions are probably about 35 tonnes, but even that
    will be swamped by the meat generated emissions big red meat eating family.

    Either people care enough about the planet to make significant changes
    to their lifestyle (meat, SUVs, monster houses, etc) or they don’t. And if they
    don’t then future generations are in deep trouble. Energy use (and emissions) in Australia is
    rising faster
    than the population. The only reason we will meet our Kyoto
    targets (we haven’t ratified anything!)
    is because we have scaled back land clearing and
    planted some plantations — no other sector has made any significant
    emission reductions.

  3. 203

    Just back from a nice trip to New Zealand (didn’t meet Raypierre, or I should have offered him a beer!), I observe some underestimation of the sheep-albedo effect: more and more NZ farms are switching from rising sheep to rising deer (which can be found as “venison” on the restaurant menu’s). As you may know, (brown) deer have a (much) lower albedo than (white) sheep…

    An even better response to GW may be to paint in white the bare rock which is all what rests a few years after parts of the tropical rainforest are cut or burned for agriculture/meat production…

  4. 204
    Ian Moseley says:

    Since these grazing creatures require grass fields many times their own surface area, would it not be more efficient to gentically engineer white grass? Does chlorophyll have to be green/

  5. 205
    Hank Roberts says:

    Chlorophyll has to be green.
    While other chemistries have been suggested,
    letting gengineered species loose that absorb different wavelengths would be really hard not to screw up. We should fix Mars and Venus first, if we’re going to experiment.

    Multicolored Photosynthetic Martian Sheep — it’s a concept

  6. 206
    SCIRE says:


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