Ptarmigans are Back! Fans of the Sheep Albedo Feedback will remember these little fellows over on the right (photo credit: Ken Tape) from the immortal paper by Squeak and Diddlesworth on the influence of ptarmigan populations on the Laurentide Ice Sheet. 
In Session C33A on Wednesday, Ken Tape of the University of Alaska presented a paper on the influence of ptarmigan grazing on shrubbification of the Alaskan tundra. It seems that when there is deep snow cover, ptarmigan browsing is concentrated on those few willows that stick up above the snow. They eat the buds, which inhibits willow growth. These tall willows are the ones that have managed to benefit most by climate warming, but the ptarmigan provide a stabilizing feedback, up to a point. An interesting thing is the ptarmigan don’t like to perch. 98% of the winter buds within a half meter of the snow surface get eaten, but only 48% of the buds above that browse level. So, if the shrubs grow fast enough to get above the browse level, they can beat the ptarmigans. This seems to be happening more and more.
In between thinking about things like ptarmigans, I have been keeping up with the Mars sessions. Truly spectacular images are coming back from the HiRise instrument flown on Mars Recon Orbiter. A. S. McEwan gave the Shoemaker lecture today, on that topic. Among other things, they have provided a whole new picture of the geology of the ancient crust of Mars.
There was also a talk on Mars that has some peripheral bearing on Earth global warming, though a rather peculiar one. Regular RealClimate readers may remember the
brouhaha over global warming on Mars. This idea has appeared in a few different flavors, mostly in conjunction with a claim that if the climate on Mars is warming, it must be the Sun or something like that, not CO2. One of the flavors of brouhaha (inflamed by this paper, with no fault implied to the authors) has to do with evidence that Mars had systematically darkened between the Viking era (1977) and the Mars Global Surveyor era (circa 2000). Darker Mars = more solar absorption = warmer. Now, since the change was supposedly due to changes in dust distribution on the surface, it’s hard to see how that climate forcing tells us anything about what should be happening on Earth. In any event, Mark Richardson, in a talk archly entitled “Some coolness on Martian global warming” showed that even the supposed albedo trend is spurious. Examining the time course of albedo patterns, he found that they varied rapidly on a yearly basis, and showed in essence that the appearance of a long-term albedo trend came from connecting two points of a more or less random time series, the second of which by chance happened to be lower. Altogether, more revealing about Mars than about Earth, but interesting nonetheless. The fact that the “global warming on Mars” argument was used at all by climate contrarians (Lindzen included) only shows how desperate they have become for arguments, and how unconstrained by reality.
Without naming names, I want to also point out a lot of really fine work in atmospheric dynamics in today’s poster session on idealized general circulation models. There’s a lot of interesting work coming out of Tapio Schneider’s guys at Caltech, on things related to synoptic eddies and the Hadley circulation. There is a lot of consistent picture building towards the idea that in a warm climate, the Hadley cell gets weaker, the cell gets wider, and the jets and storm tracks penetrate further poleward. This all goes under the general rubric of “expansion of the tropics,” and at least the thermal signature has been observed in the real world. It is in line with theoretical concepts of how the atmosphere works. Chalk up one more aspect of climate change which we can say we pretty much understand.
With a bit of time to spare, I sauntered by the Princeton University Press booth to catch up on the offerings. They have a very fine list in Earth science, including Richard Alley’s book, “The Two Mile Time Machine,” and Andy Knoll’s excellent book on the first three billion years of life. Soon they will have Dave Archer’s new book on the long term effects of global warming, which is still in search of a good title. Suggestions welcome.
Moving along, Susan Solomon gave the Bjerknes lecture. This was mostly a review of the history of science and science policy concerning the ozone hole. She contrasted the challenges of controlling CFCs with those of controlling CO2, and showed some similarities and differences. A common thread between the two is that scientific assessments (like IPCC) have played a central role in treaty milestones. It is also worth noting, as she pointed out, that the Montreal Protocol has contributed significantly to climate change mitigation, because CFCs are good greenhouse gases. At the time of peak CFC emission, the CO2 equivalent of CFC emission was equivalent to a third of the actual CO2 emissions. Without Montreal, CFC emissions today would be much higher. By some estimates, Montreal has contributed more to global warming mitigation than Kyoto, and can do more in the future by promoting CFC replacements that are climate-friendly. This is not to say that a Kyoto follow-on is unnecessary. It’s just a reminder that in some areas, we have made some progress in greenhouse gas mitigation.
Moving from high up right down to the surface of the planet, we get back to an issue that was much in evidence in our previous dispatches: climate change in the Arctic. Hansen and Nazarenko (PNAS 2004) resurrected interest in the effect of soot on snow albedo, suggesting that it might account for a good deal of rapid Arctic warming. There was, however, a need for much more data on snow albedo. Steve Warren presented new data from his ongoing snow albedo project (see his project page here ). This involved snow samples from an impressive network of volunteers, including one 4000 km snowmobile trek across the Canadian Arctic, and the first snow samples in restricted areas of the Russian North. Except for the Russian North (where earlier data isn’t available), the soot contents seem to have gone down substantially since the 1980’s, which is in accord with the general cleaning of air samples. Greenland is very clean, but there is some concentration of soot in melting snow, which may accelerate the Spring snowmelt. While emphasizing that soot is still important and needs to be understood better, Steve suggested that insofar as soot forcing seems to be decreasing, it is not a good candidate for accounting for the acceleration of Arctic warming in the past two decades.
Aside from the fact that it’s 2AM and I’m writing this at the end of the AGU honors banquet, I won’t belabor Lonnie Thompson’s Frontiers in Geophysics lecture since it was webcast and I imagine that all of you who were interested have already had a look at it. As one expects from a Frontiers lecture, there wasn’t much new for the folks who were already in the thick of the subject (since it’s for a more broad audience) but it was a great lecture nonetheless. Lonnie gave a general overview of the climate change problem, with particular emphasis on what has been learned from tropical ice core investigations. He had a number of great pictures of the field work, including some indication of the size of the herd of yaks needed to get a 600m ice core down from the Himalayas in insulated core boxes. Some take home points are that 98% of the named Alaska glaciers are retreating, 95% of 612 studied Tibet glaciers are retreating, and 98% of monitored Alpine glaciers are retreating. He also had incontrovertible evidence that there has been massive melt on Kilimanjaro. This included ice cores that showed characteristic elongated air bubbles in the past few decades, whereas earlier parts of the core show intact bubbles. There is obvious ocular proof of melting on Kilimanjaro, and it is baffling that the likes of Georg Kaser and Philip Mote can’t seem to believe the obvious evidence there for anybody to see. It’s not sublimation. There’s lots of melt. Lonnie also pointed out, that with regard to tropical mountain glacier retreat in general, the rapid retreat supports the vertical amplification with height seen in GCMs and in the moist adiabat, suggesting that evidence to the contrary from radiosondes may be more a data problem than a physics problem.
Tonight was the AGU Honors ceremony. Congratulations especially to all of those who have contributed so much to advancing the state of understanding of climate: to Susan Solomon (who was awarded the Bowie Medal), Richard Alley (who was awarded the Revelle Medal) and Amy Clement (who was awarded the Macelwane medal). These and other medalists were feted at a very fine banquet, and needless to say, once more, a good time was had by all. Susan Solomon gave an especially inspiring acceptance speech. “The Nobel prize awarded to the IPCC recognizes unselfish cooperation at its best.” “Never before has there been such a need for society to make good collective decisions [about climate change],
informed by good science.” Susan, needless to say, was chair of the IPCC Working Group I.
Overheard at the banquet: “Richard Alley is a C-Span Rock star!” (referring to Richard’s indefatigable efforts to educate Congress of the reality of global warming)
The Honors Evening was another real inspiration. Look, guys and gals, this is a really, really talented crew. How could you not believe them when they say global warming is a real problem?
A certain V. Courtillot and C. Allegre were also in evidence,though not encountered. What can I say, but that it is fortunate that the custom of throwing down the gauntlet and challenging to duels has fallen out of fashion. Magnetic fields vs. CO2 at 20 paces!
More tomorrow.
Re #29 [Edward Greisch]
For some reason, this post has failed to appear despite being sent several times. One more try…
The IPCC do not agree with you that nuclear power is the silver bullet. I quote from the “Summary for Policymakers” of the report of WG III:
“Given costs relative to other supply options, nuclear power, which accounted for 16% of the electricity supply in 2005, can have an 18% share of the total electricity supply in 2030 at carbon prices up to 50 US$/tCO2-eq, but safety, weapons proliferation and waste remain as constraints.”
On the whole, I trust the IPCC more than a group of nuclear enthusiasts.
Moreover, there seems scant chance that China And India will abandon use of their abundant cheap coal to buy uranium on a large scale from abroad. Both are expanding their nuclear power programmes (so they are clearly not opposed in principle), but at a rate which hardly makes a dent in their rapid increase in CO2 emissions; only CCS or economic collapse are likely to do that.
I note that the review of Comby’s book you cite begins: “AT A TIME when most of the media and politicians seem to be brainwashed by antinuclear cults…”. This might possibly indicate to some readers that the reviewer has a rather partisan approach to the issue.
Re $51: [The IPCC do not agree with you that nuclear power is the silver bullet.]
Maybe because there ARE no silver bullets; no one solution that magically makes the problem go away. We need to be open to using anything and everything that might help, and even then the outlook is not encouraging.
[Moreover, there seems scant chance that China And India will abandon use of their abundant cheap coal…]
But we could say as much for any CO2-producing technology and country, adjusting the verbiage as appropriate: it’s unlikely that Americans will give up cheap electricity and SUVs, it’s unlikely that Brazilians and Indonesians will stop burning down the rain forest; it’s unlikely that North Africans will stop grazing their flocks on marginal grasslands…
Regardless of what China & India do, if the US or other countries replace coal-fired generation with nuclear, solar, wind or whatever, that reduces the world’s CO2 output. We’ve wasted too much time waiting for the other guys to agree to go first. We need to start, then apply whatever pressure we can to get the rest to follow.
Re #52 (James) “Re #51 [Moreover, there seems scant chance that China And India will abandon use of their abundant cheap coal…]
But we could say as much for any CO2-producing technology and country, adjusting the verbiage as appropriate:”
I notice you carefully omit the alternative implicitly proposed: CCS.
“Regardless of what China & India do, if the US or other countries replace coal-fired generation with nuclear, solar, wind or whatever, that reduces the world’s CO2 output. We’ve wasted too much time waiting for the other guys to agree to go first. We need to start, then apply whatever pressure we can to get the rest to follow.”
I have no quarrel with that, nor with the point that we need to be open to using anything that might help – but it does not follow, as you seem to think, that we should necessarily use everything that might help: we need to think about what can be done fastest and cheapest (because resources of capital, labour and expertise are limited, and different approaches require different infrastructure), and with fewest undesirable side-effects. As I’ve noted before, to take an extreme case, developing and releasing a pathogen that would kill most of the world’s population might be a very effective counter to AGW, but I (and I am sure, you) would find it unacceptable. As you will be aware if you recall my previous posts, my position is that nuclear power is best avoided if and where possible, primarily because of the ineradicable links between nuclear power and nuclear weapons (I note that the Bush administration is opposed to Russia supplying uranium to Iran because of the risk the Bushehr reactor could be used to produce weapons-grade plutonium) – but that it is not going to disappear in the short term (France and Japan, for example, have invested so much money and prestige in it they are unlikely to change course).
Re #53: [I notice you carefully omit the alternative implicitly proposed: CCS.]
Sure, for the same reason I omitted to suggest that everybody race out and start building fusion power plants: because we don’t know how to make it work in practice. Can the capture be done economically? Will the Chinese and Indians, or even the Americans, be willing to do it if it significantly increases the cost of electricity? Will the stored CO2 stay stored for the next few million years, or will it come bubbling back out in a hundred or so?
Re #54 (James) “Sure, for the same reason I omitted to suggest that everybody race out and start building fusion power plants”
James, the comparison is ridiculous, as I’m sure you know. Read the IPCC WG III special report on carbon capture and storage, or at least the summary for policymakers.
Here is what the latter says about costs (EOR is enhanced oil recovery):
“Application of CCS to electricity production, under 2002
conditions, is estimated to increase electricity generation
costs by about 0.01–0.05 US dollars16 per kilowatt
hour (US$/kWh), depending on the fuel, the specific
technology, the location and the national circumstances.
Inclusion of the benefits of EOR would reduce additional
electricity production costs due to CCS by around 0.01–
0.02 US$/kWh (see Table SPM.3 for absolute electricity
production costs and Table SPM.4 for costs in US$/tCO2
avoided). Increases in market prices of fuels used for
power generation would generally tend to increase the
cost of CCS. The quantitative impact of oil price on CCS is
uncertain. However, revenue from EOR would generally
be higher with higher oil prices. While applying CCS to
biomass-based power production at the current small
scale would add substantially to the electricity costs, cofiring
of biomass in a larger coal-fired power plant with
CCS would be more cost-effective.”
China and India are much more likely to be willing to pay that amount extra than to leave all that coal in the ground and make themselves heavily dependent on uranium from abroad.
Given the absurdity of some of the claims made (e.g. for the “net environmental benefit” of Chernobyl), I have the impression that you and a few other posters have a strong emotional attachment to nuclear power, just as many of its opponents have a strong antipathy to it. In general terms, either attachment or antipathy can lead to distorted thinking.
Re #55: […the comparison is ridiculous, as I’m sure you know.]
No, I don’t know that at all. We have two theoretically possible but totally unproven in practice technologies. I’ll grant you that I’m not an expert on the subject, but practical CCS seems far more difficult to accomplish than fusion. How in the world would you even separate the CO2 from the exhaust stream? Chemical reactions? What reversible reaction, and what are the energy losses? Cooling it until it solidifies, or under enough pressure to liquify it? That takes lots of energy. Maybe selectively permeable membranes? Then you have the costs of transport and compressing for storage, and still absolutely no guarantee that it’s going to stay in storage once it’s put there.
But if you don’t like the fusion comparison, how about that other pie-in-the-sky scheme, the hydrogen economy? That might be a better comparison, since the technical problems are more alike.
“I have the impression that you and a few other posters have a strong emotional attachment to nuclear power…”
Your impression is wrong. I don’t have any particular attachment to nuclear power. My attachment’s to reducing CO2 levels before the world’s completely screwed up. Show me another technology that will do what nuclear will with fewer side effects, and I’ll be overjoyed. I do have a strong attachment to dealing from evidence rather than mythology, and most of the public opposition to nuclear power seems just that.
I also have a very strong opposition to the effects of fossil fuel plants, and coal in particular. That’s not limited to the CO2: I’d a thousand times rather live in Chernobyl’s dead zone than in some of the coal mining areas I’ve passed through.
Re #56 “I’ll grant you that I’m not an expert on the subject, but practical CCS seems far more difficult to accomplish than fusion.”
Don’t argue this with me, I’m not an expert either. Argue it with IPCC WG III.
“I don’t have any particular attachment to nuclear power.”
Frankly, I don’t believe you, because you so persistently ignore expert opinion without adequate reason.
“Show me another technology that will do what nuclear will with fewer side effects, and I’ll be overjoyed”
Again, argue the point with IPCC WG III, who assess nuclear’s potential contribution as minor.
In the absence of some reasoned explanation of where you believe IPCC WG III have gone wrong on the two key points I have reiterated in this post, I will not respond further in this thread.
James (56) — You could (and should) first take the time to learn something about CCS before posting regarding it. It is neither terrribly difficult nor costly. Indeed, the initial studies appear to indicate that the sequestered carbon dioxide chemically binds to matter in deep saline formations, making the sequestration even more secure than had been earlier anticipated.
> I’d a thousand times rather live in Chernobyl’s
> dead zone than in some of the coal mining areas…
As an individual, selfishly, I agree with you, at my age it wouldn’t make any great difference if I was careful where I put my fingers.
But as a member of the species, this is a Darwin Award self-nomination, because fitness is measured in viable grandchildren.
Nick and James, It is easy to get caught up in an infinite loop on a subject as nuclear power. I think it suffices to say that no matter whether we rely on nuclear, renewables or both, we face a very difficult task when it comes to meeting future energy demand without increasing CO2 emissions. I think it is a mistake to prejudge the solution. We will have to weigh risks, costs and consequences as we go and take the course that seems most likely to yield success at the time we have to decide.
Re #59: […fitness is measured in viable grandchildren.]
I think fitness is better measured in genes which survive. So if for instance you produce a lot of viable grandchildren, just like everyone else, they exceed the food supply and wind up killing each other off, demonstrating that too many grandkids results in negative fitness. Or if you don’t have grandkids, but spend your time ensuring the survival of your close relatives’ grandkids, you’ve demonstrated fitness without personally reproducing.
James posts:
[[I’d a thousand times rather live in Chernobyl’s dead zone than in some of the coal mining areas I’ve passed through.]]
I almost said, “I’d rather you did, too,” but I restrained myself at the last minute.
-Pittsburgh boy
James and Hank, Re your discussion of fitness–and WAY OFF TOPIC
Hank: […fitness is measured in viable grandchildren.]
James: I think fitness is better measured in genes which survive.
Actually, James comment is more general. On average, a grandchild will carry only ~1/4 of the genes of the grandparent, and if a grandparent produces a lot of viable offspring, the good genes from said grandparent tend to survive. The distinction is very important when it comes to so-called “altruistic” behavior in social insects and a few rare mammals such as naked mole rats. In such species, only the “queen” reproduces, with most females fulfilling altruistic functions such as gathering food, tending to young… How can this make sense? Well, it turns out that in such social species, there is a high degree of genetic relatedness. Thus, even though they do not reproduce, an altruistic nonbreeder would be more likely to project its genetics into the next generation as long as its altruistic behavior provided sufficient benefit to the next generation.
Re #63 Can’t resist, even though way off topic. Actually, Ray (as you may well be aware), with regard to the Hymenoptera (ants, bees, wasps – but not termites), there’s an extra twist. They have a “haplo-diploid” genetic system: males have only one set of chromosomes, and indeed, one parent. The result is that a female is more closely related to her (full) sisters than to her daughters – but the queen often mates with multiple males, and stores the sperm for years. The queen and workers also “prefer” different sex ratios in the young, and it turns out that a hive/nest is in genetic terms a “workers’ republic” rather than a “monarchy” – the workers get their way because it is they who rear the young. There are many other species, including ours, where individuals often help raise their sibs, and hence display their inclusive fitness other than by reproducing. We also have to be careful with terms like “altruistic” – you’re right to use scare-quotes. Sometimes, biologists restrict the term’s meaning to actions which favour others’ genes, rather than others as individuals – but if you do that, an infertile person murdering their entire family to obtain their wealth turns out to be highly “altruistic” behaviour! My favourite quote on all this is from J.B.S. Haldane: “I will give my life for two brothers, or eight cousins.”
Nick–My lovely wife (an environmental scientist) has pointed out that the Haplo-dploidy in bees does indeed mean that the males only have half the genetic material of females, and that this proves that Monty Python was correct–Eric the half be was in fact half a bee.
http://www.lyricsdepot.com/monty-python/eric-the-half-a-bee.html
> J.B.S. Haldane: “I will give my life for two
> brothers, or eight cousins.”
Accurate math when cousins don’t marry; for honeybees and other highly related groups, the numbers differ.
#49/#50
A furnace in the basement of a house turns on periodically. The house heats slowly to thermal equilibrium. There no correlation between furnace output and house air temperature. Does this mean there is no cause and effect?
Surely you know where this goes. (You might think twice before labeling this a “straw man”.)
Richard #67. Huh? Methinks you have an ill-posed problem. I don’t have the foggiest notion what you are driving at. Do you?
Richard, the numbers may have changed because of delayed posts being released from the hyperactive spam filter (this has hit WordPress blogs a lot recently). So it’s really hard to guess what you’re replying to.
If you’re arguing that Earth is heated from internal sources like Jupiter, I don’t think you’ve made a case.
Yes, Ray, I do. Do you recall this one?
“Say it three times every night before going to sleep: Temperature goes up. Solar stuff goes up and down and up and down and up and down. You can no more make a trend out of that than you can make a silk purse out of a sow’s ear.”
Tell me about “the pipe” in that context. We’ll see whose problem is ill-posed.
[Response: I don’t see any contradiction here. What in the world are you trying to get at? In your furnace example, there is a phase lag between the periodic forcing and the periodic temperature response. The phase lag tells you about the thermal inertia of the house. That’s standard signal processing stuff, and in fact routine in the way the Earth’s response to the seasonal or solar cycle is analyzed. –raypierre]
Yes, phase lag, raypierre. Now we’re getting somehwere. Please continue.
Ok, I’ll help. What is the chance that the time scale of the varying periodic input is faster than the time scale of integration performed by the body with the thermal inertia? And what would be the consequence?
[Response: Try again. There is no one single thermal inertia for the Earth.There are a vast range of time scales involved. The atmosphere has time scales of days to months, above the boundary layer. The ground itself has a continuous range of scales, because of the nature of heat diffusion. The mixed layer of the ocean has a time scale of a few years, the deep ocean maybe a few centuries to a thousand years. Glaciers can have surges that respond on a times scale of days, and accumulation times that can be in the millennia. Carbonate dissolution in the Ocean introduces time scales on the order of ten thousand years. Vegetation feedback is in between. Silicate weathering has the chance to buffer climate on time scales of a half million years or more. Take your pick. I don’t think you are making much progress on refining your question. –raypierre]
Re #63, 64, and related genetics: Interesting, but I was thinking of a somewhat different situation, involving different strategies for maximizing reproductive fitness. At one extreme you have what might be called the codfish approach: produce millions of offspring in hopes that some will survive. At the other we have what mammals, and notably humans, do: have few offspring, but invest large amounts of energy in seeing that they (or those of other members of your pack/herd/tribe) survive.
So, when faced with the prospect of limited food supply, it would seem that the optimum reproductive strategy would be to have still fewer offspring, giving those a better chance of survival, than to have more who are unlikely to survive the increased competition, which they’ve created simply by existing.
[Response: hmm all very interesting, but aren’t we straying rather far afield from our topic? –raypierre]
Re: inline response in #72
With a solar cycle varying on the decadal time scale and the mixed and deep ocean layers bracketing that – with integration times of a few years and a few centuries – does it make sense to you to assert that a pulsed input must lead to a pulsed output? Is it impossible that the input is buffered, to lead to a gradual rise in ouput? Maybe it is logical, I don’t know. I would simply like to hear your justification for the statement in ‘Les Chevaliers’ that inputs that go up and down and up and down can not lead to a rising trend in output. This view seems blissfully ignorant of “standard signal processing stuff” and maybe even some basic facts about the oceans. But enough. I come to hear the experts speak, not myself.
Richard Sycamore, OK, I’ll bite. First, most of the drivers aren’t really periodic. Second, do you know of a physical system that responds to a periodic input with a monotonically increasing response? Can you even construct a differential equation that would behave in such a manner (without imaginary coefficients, I mean)?
And unless you can find some really serious heretofore unknown feedbacks, Mr. Sun isn’t going to be able to drive the current warming.
Look, Richard, do yourself a favor and actually learn something about the physics of climate and greenhouse gasses. You have access to everything you need on the front page of this site. Please ask questions, but I don’t think you are going to teach Gavin and Raypierre about the subject they have been studying for decades just yet.
ERe # 75 Ray Ladbury: ” …do you know of a physical system that responds to a periodic input with a monotonically increasing response? ”
Sorry for going off topic a bit: If I understand “monotonically increasing response” correctly, a classic example of a physical system showing this is muscle temporal summation:
“Temporal summation is produced by stimulating the muscle rapidly enough so that one contraction is not finished before another begins. Thus, the effect of the second contraction is added to at least a part of the first contraction, and so on. If the muscle is stimulated rapidly enough, succeeding contractions may come so close together that no relaxation occurs between contractions. When this occurs, the smooth state of contraction known as tetany has been achieved. The frequency of stimulus necessary for tetanization varies depending on the particular muscle.” http://bioweb.wku.edu/faculty/Crawford/frogmusc.htm
An illustration of this can be found in Figure 8-7 of this online preview of this physiology textbook: http://books.google.com/books?id=cj9S_10muCYC&pg=PA123&lpg=PA123&dq=muscle+temporal+summation&source=web&ots=rw0TRVBR0y&sig=piLRXnqJuXxDxUH171ckqHtJAM4
If I am mistaken about this, please feel free to correct me.
Re #74 (Richard Sycamore) “But enough. I come to hear the experts speak, not myself.”
You could have fooled me!
Chuck, That is interesting, but I don’t think it would qualify as a monotonically increasing response–and I certainly don’t see how it would apply to climate, since the energy for contraction is not supplied by the stimulus, but rather by the ion pump in the muscle cells. The stimulus merely triggers release of the energy. Richard has proposed no source of energy other than insolation.
#77 That you’re so easily fooled is not my problem. Good luck with that.
#78 Ray, Hank, et al. perhaps my question is so ill-posed that it is unanswerable in its current form. I do not think so. Open-ended, perhaps. But ill-posed? Not likely. I’ll let you think about it and will check in periodically. Meanwhile, instead of attacking what I’ve said, why don’t you help me try to ask a better question? If you want to cite some literature, I will read it.
Richard, the question sounds like you’re fishing for a particular answer. If you think it’s answerable, you might suggest how, and what kind of experiment you could do to prove your answer wrong.
#80 I am, Hank. And I thank you for your civility.
If the time lag referred to by raypierre in ‘Flat Earth’ thread is short compared to the duration of the forcing, then GMST would be expected to closely follow the forcing, with little lag. [This is precisely the scenario that leads to “up and down and up and down and up and down” expectation for periodic solar forcing.] Alternatively, if the time lag is long, then the change in GMST would considerably lag the forcing and temperature would continue to change substantially before the climate system reached a new steady state.
In particular for a situation in which climate is being forced by increasing solar activity, the increase in temperature beyond that realized at a given observation time that might be expected in response to forcing that has been applied until that time has been denoted “unrealized” or “committed” warming that is “in the pipeline” and is attributed to “thermal inertia”.
We are told that mixed ocean layers have a response time of several years and deep ocean of several centuries. I want to understand as much as possible how that estimate of several years is derived, and why it is not, say, 20 years. I want to understand the factual basis behind raypierre’s assertion that periodic solar forcing must lead to a periodic response. To me, this is not inuitively obvious. Although it is clear why that might be the case of the time constant was short relative to the time scale of forcing.
In short, I want to know if this up-and-down expectation is raypierre’s reasoned assessment, or just a quick one-liner made in rhetorical haste.
[Response: You can read about the theory of linear mixed layer response in many places, including Chapter 8 of my book, a draft of which is available online. Follow the ClimateBook link at geosci.uchicago.edu/~rtp1. You can get a rough idea of the response time of the deep ocean by treating the ocean as a single mixed layer a few km deep, and such crude estimates are borne out by the response times in dynamic general circulation models. In a nonlinear system, of course you can get an aperiodic response from a periodic forcing but (a) even in such cases, the linearized system gives you a good idea of the damping of the signal due to thermal inertia and (b) you have to convince me what the strong nonlinearity is that could give such an effect in the face of the exceedingly weak amplitude of the solar cycle driving. –raypierre]
#81 You sure have a way of making things more difficult and more complex than need be. We can restrict our attention to linear models for my purposes. I’m not invoking any strangely nonlinear behavior.
I read your chapter, thank you. Many equations. Let’s use words. In your language, my question is what is your proof that the ocean does not have the thermal inertia required to attenuate the effects of the solar cycle? Context. In your chapter you show that the well-mixed layer of the ocean has a relaxation time of 1200d, and that this amount of thermal inertia is sufficient to attenuate, say, the annual seasonal temperature cycle. I am asking for the same calculation, but for the 11y solar cycle – the subject of your comment in ;Les Chevaliers’. [Yes, I could go get a PhD in climatology and do the calculation myself. I was hoping not to have to do that.]
If such a simple question can not be answered, I give up. I would have thought it obvious from the start, when I first mentioned the furnace analogy. No one has told me yet why it is a poor analogue. Just mocking from the peanut gallery.
Richard, Did you ever take a differential equations class? The nonlinearity Raypierre is talking would be reflected in your differential equation by a complex term (that is a term that involves SQRT(-1)). Where would you get such a term for any process that is significant in the energetics of climate. Moreover, the main period evident in solar activity is the 11 year cycle. That has been around as long as we have records going back–well back into geologic time. Why would you suddenly get a nonlinear term turning on now?
Also, if you are looking for a delayed response, the delay has to be at least 50 years, since it’s been that long since we had insolation increasing. Where has all the energy been hiding all this time?
Finally, I am curious why you find the greenhouse effect so incredible that you are willing to posit unknown physics in its place when it does a perfectly good job of explaining the current warming both qualitatively and quantitatively.
Re #82 (Richard Sycamore) “We can restrict our attention to linear models for my purposes. I’m not invoking any strangely nonlinear behavior.”
Then I would think (correct me if I am wrong, you mathematicians and physicists) there is absolutely no way a fluctuating input could cause a monotonically rising output.
“I read your chapter, thank you. Many equations.”
There’s a reason for that, Richard.
Richard: Let us simplify the problem. Assume for the sake of argument that from the year 1000 to 1900 the TSI has not changed, so that by 1900 we have an equilibrium situation (with some periodicity from the solar cycle, but no long term drift). Now increase the solar forcing from 1900 to 1950, after which it becomes constant again.
We would expect to see that the increase in rate of temperature rise would reach a maximum in 1950. After that, there might be continuing temperature rise, but the rate would drop as the system started coming into a new equilibrium.
Of course, this is not what we see: despite no rise in total solar output since 1950, we have seen the fastest rise post 1980. Now, you could argue some of that could be related to a drop in aerosols, but the timing just doesn’t work out well. And you’d still need to explain why the well understood radiation increase from GHGs wasn’t adding its own warming…
Re 82- In order to demonstrate that a proposed explanation for an observed phenomenon is likely to be true, it is only necessary to show that the explanation is consistent with the known laws of physics and that it yields the observed results. It is not necessary to falsify all other possible proposed explanations (which, as we have seen, seem almost limitless!). If two explanations seem to meet this test, then there is an error somewhere that has to be thrashed out.
Thus far, no one has come up with anything to explain the current warming that meets this test that does not include AGW as the primary component. Moreover, since the AGW explanation is so robust in terms of the physics, the observed data, and multiple lines of evidence, any proposed alternative explanation would have to show the error in the AGW analysis. And it would have to do so based, not on expert opinion, but on verifiable scientific analysis published in the peer-reviewed literature.
So what you are getting from the busy scientists here is the real science. It is not realistic to expect them to spend time analysing speculative alternative explanations for global warming. You do it, publish it, and they will be glad to take a look at it.
Richard, I’m afraid the furnace analogy escapes me entirely. With the furnace, heating occurs when the furnace is on and stops when it turns off. Yes heat propagates throughout the house via convection, but there really is no delay. The other thing you need to appreciate is that attenuation of a cycle does not in any way lead to a monotonic increase, but rather a damped (or diminished) response. Again, if you understand differential equations, that’s the easiest way to look at it. In the absence of a driving force, you will have the natural behavior of the system (analogous to the homogeneous solution of the Diff. Eq.). Turn on a driver, and the response of the system will follow, more or less, the driver (that is, the inhomogeneous solution).
For your solution to be operative, there would have to be some sort of heat reservoir that soaked up all that heat in the period 1900-1950 and has been hiding it from us ever since, and then, just by chance in about 1980, started doling out the heat at just the right rate to make it “look like” a greenhouse forcing. It would also have to be doling out more heat in Winter than Summer, and at night rather than during the day. And even then, you would have to explain why the known physics of greenhouse gasses suddenly decided to stop operating when we reached a CO2 level of about 300 ppm. Einstein once said that the most incomprehensible thing about the Universe was that it was comprehensible. Comprehend that and you’ll understand why science works.
I see my last post has been disallowed. But the well-posed question is still not resolved.
Ray, please stop trying to defend something that I am not questioning – greenhouse thory – and please answer the question that I am asking. raypierre says the time constant of the ocean mixed layer is 1200d. I want to know how that computation was made and why he is certain the number is not something larger, like 4800d. The size of this number would indeed influence the pattern of output (GMT) from a pulsed input (11y solar cycle). Nick Gotts in #84 asks to correct him if he is wrong. I am asking that you provide the proof if he is correct.
Your #87 states that my analogy escapes you, but the second paragraph has the gist of it. The ocean is a large heat reservoir. It has heat buffering capacity.
I will consider answering your question about GMT 1900-2007 AFTER my question is answered, not before.
You realize you’re talking about a variation of about one in thirteen hundred, between solar max and solar minimum, right?
Ray’s on holiday, as are all those with a life, leaving the thread open for the rest of us (grin). On second thought, I’ve got things to do myself from here on.
Happy holidays, all.
You keep telling me not to ask the question, arguing that it’s not important. Rather than waste bandwidth doing that, why don’t you just answer the question? I’ll check back 28 Dec. Thanks.
Richard, I believe some of the best measurements come from radioisotope studies after bomb tests. You can read about them in some detail here:
http://www.aip.org/history/climate/oceans.htm#L_0488
http://www.aip.org/history/climate/Revelle.htm.
Moreover, I fail to see how a heat reservoir is going to bring you an accelerating warming trend. Moreover, given that the oceans are warming too, I would think this poses a bit of a problem for your hypothesis.
Re #90
Try the following as a good start:
http://links.jstor.org/sici?sici=0012-9658%28198406%2965%3A3%3C970%3AMTEITG%3E2.0.CO%3B2-Y
Modeling Terrestrial Ecosystems in the Global Carbon Cycle With Shifts in
Carbon Storage Capacity by Land-Use Change
William R. Emanuel; George G. Killough
Ecology, Vol. 65, No. 3. (Jun., 1984), pp. 970-983.
Ray #91 You are attributing things to me that I never said, so I don’t quite follow. But I will listen. I don’t have a hypothesis, much as you would like to attribute one to me. I want to understand why Pierrehumbert said what he did about “up and down and up and down” solar cycle input vs. increasing trend in GMT ouput. He was suggesting that a causal relationship is not possible given a lack of pattern match. I want to understand the role of ocean heating and ocean mixing as a possible source of delay and of buffering of heat as a driver of GMT. If you don’t want to answer the question, fine, just say so. Ultimately it’s Pierrehumbert’s assessment that interests me, as it was him that made the statement.
accelerating trend? I don’t remember saying anything about that. Why would I? [Never mind – that’s a distraction. Focus on the question.]
Richard, Forgive my skepticism, but I would have thought that if you were really interested, you would have checked out the references I provided, which do pertain to your question of how we know ocean mixing times.
You also have not answered the question: If the oceans are warming the rest of the world, why are they warming, too?
And the accelerating trend I refer to is the current warming trend–warming due to a heat reservoir would tend to be most rapid right at first and then taper off. Consult your old differential equations text on why a periodic forcer cannot result in monotonically increasing response in a linear system. Merry Xmas, by the way. Ray
I see I’ll be getting nothing but the runaround for Christmas. Ah, well, there’s always New Years.
Ray #91, your link was inadequate. I already read Pierrehumbert’s excellent book, and it came close to almost giving an answer.
Phil #92, your link was irrelevant.
Ray #93, the oscillations get folded into the ocean’s convection. I fail to see how your freshman differential equations argument applies to a global mixer.
Perhaps, Richard, you should work on refining what it is you want to know. The link I sent you describes how they determined timescales of ocean mixing–which is what you said you wanted.
Changes in climate will be described by a differential equation, Richard. That differential equation will be either linear or nonlinear. You said you were satisfied with a linear equation. For that reason, you cannot get a monotonically increasing solution out of the differential equation with an oscillatory input. Perhaps you should review Freshman Diff. Eq.. Or perhaps you can provide a physical counter example…?
Ray, what I want to know was worded very precisely in the comment that got censored, in between #87 and #88. So I will try again. (1) Please show me the calculation that was used to determine that the ocean heating time constant is 1200d. (2) Please explain how you know it is not something much larger, such as 2400d or 4800d. (3) Please explain why such a long time constant would not cause a periodic solar input to integrate to a virtually linear monotonic rise in GMT. (4) By all means, use differential equations if it helps your case. It will be interesting how you use them to represent ocean fluid dynamics. Whatever you do, just don’t wave your arms and tell me “calculus makes it so”. Show me the equations. I’m prepared to accept a rational argument. Just don’t give me rhetoric.
If you’ve lost track of the context, please refer back to the original parapraph and graphic in Les Chevaliers. This is all about Pierrehumbert’s statement that “up and down and up and down and up and down” solar input can not possibly lead to a linear increase in temperature. As you know, I’ve given you a physical example already. If you are suggesting you’ve already proven it to be irrelevant, I would disagree.
I’m afraid I can’t be much clearer than this. Thanks, anyways, for helping me try to figure out what it was raypierre was trying to say with that statement.
Richard, if we have a periodic input (or in this case, a quasi-periodic input) to a system, the output will tend to follow it. If you put in a reservoir, the response of the system will be delayed, but still periodic (or quasi-periodic) with roughly the same perodicity as the input. The only way you get a growing output from a periodic input is if the input resonates precisely at the resonant frequency of the system. Since we are dealing with a quasi-periodic input, this does not apply. And even if it did, we would still expect oscillatory behavior–just oscillation with increasing amplitude from period to period. That’s not what we see.
As to the oceans, the era of nuclear testing yielded a treasure trove of information–including the rates of flow, etc. of ocean currents. The C-14 spike from the nuke tests was a wonderful pulse source that elucidated a lot of the time dependence of the atmosphere and oceans. Read the reference from Spencer Weart’s page I provided (it is clear that you haven’t). And you still haven’t explained how the ocean can be warming the globe even as it is itself warming–violating the 1st law of thermo is a neat trick if you can do it.
As to your “physical example”, I presume you are referring to the house with a furnace. First, in your example, the house will warm fastest when the furnace is on. If the thermostat is placed in the far corner away from the furnace, there will be a delay, but you will still see a pulse of warming that diminishes with time. This is nowhere near what we are seeing with the climate, where warming is accelerating with time.
Look, Richard, all I can suggest is that you look into the history and science of the subject. It is clear you have not done so.
And you have not proven your case, Ray. You merely repeat yourself. I understand well your POV. Enough. I want to see the equations. I’ve read your references and the answer to my question is not there. My guess is you can’t answer the question so you try to dodge it by sending me off on these tangents. It’s ok if you don’t have the means to make your case. I’ll just wait for raypierre.
Re #95
“Phil #92, your link was irrelevant.”
I suggest you read it, I think you’ll find it’s more relevant than you appear to think.