This comment from Dr. Robert Brown at Duke University is elevated from a comment to a full post for further discussion. Since we have a new paper (Shepherd et al) that is being touted in the media as “certain” using noisy data with no stable baseline, this discussion seems relevant.
So wait, you are saying that fossil fuels do not cause warming, but that if we shift away from them to clean energies, there is a risk of the earth cooling? Uh, could you just think that through and try agan?
No, that’s just some people on the list who are “certain” — with no more grounds than those of the warmists — that the Earth is about to cool. In the long run, of course, they are correct — the current interglacial (the Holocene) is bound to end at some point soon in geological time, but that could be anytime from “starting right now” to “in a thousand years” or even longer. Some are silly enough to fit a sine function to some fragment of data and believe that that has predictive value.
The problem is that nobody knows why the Eocene ended and the Pleistocene (the current ice age) started, and nobody knows exactly where and why the Pliestocene is a modulated series of glaciations followed by brief stretches of interglacial.
There are theories — see e.g. the Milankovitch cycle — but they have no quantitative predictive value and the actual causal mechanism is far from clear. So we do not know what the temperature outside “should” be, with and/or without CO_2. We do know historically that the Little Ice Age that ended around 200 years ago was tied for the coldest century long stretch of the entire Holocene — that is, the coldest for the last 11,000 or so years (where it might surprise you to learn that the Holocene Optimum was between 1.5 and 2 C warmer than it is today, without CO_2).
So the fact of the matter is that there is a risk of the Earth cooling — in fact, there is a risk of a return to open glaciation, the start of the next 90,000 year glacial era — but it is not a particularly high risk and we have no way to meaningfully do much better than to say “sometime in the next few centuries”. CO_2 might, actually, help prevent the next glacial era (or at least, might delay it) but even that is not clear — the Ordovician-Silurian ice age began with CO_2 levels of 7000 ppm. That is around 17 times the current level, almost 1% of the atmosphere CO_2 — and persisted for millions of years with CO_2 levels consistently in the ballpark of 4000 ppm. If the Earth’s climate system (which we do not understand, in my opinion, well enough to predict even a single decade out let alone a century) decides it is time for glaciation, I suspect that nothing we can do will have any meaningful effect on the process, just as I don’t think that we have had any profound warming influence on the Earth so far.
The fundamental issue is this. We have some thirty three years of halfway decent climate data — perhaps twice that if you are very generous — which is the blink of an eye in the chaotic climate system that is the Earth. There has been roughly 0.3 C warming over that thirty-three year stretch, or roughly 0.1 C/decade. It is almost certain that some fraction of that warming was completely natural, not due to human causes and we do not know that fraction — a reasonable guess would be to extrapolate the warming rate from the entire post LIA era, which is already close to 0.1 C/decade. It is probably reasonable to assign roughly 0.3 C total warming to Anthropogenic CO_2 — that is everything, not just the last thirty years but from the beginning of time. It might be as much as 0.5C, it might be as little as 0.1C (or even be negative), but the physics suggests a warming on the order of 1.2 C upon a complete doubling of CO_2 if we don’t pretend to more knowledge than we have concerning the nature and signs of the feedbacks.
At the moment there is little reason to think that we are headed towards catastrophe. When the combined membership of the AMA and AGU were surveyed — this is surveying climate scientists in general, not the public or the particular climate scientists that are most vocal on the issue — 15% were not convinced of anthropogenic global warming at all, and over half of them doubted that the warming anthropogenic or not would be catastrophic. It’s the George Mason survey — feel free to look it up. The general consensus was, and remains, that there has definitely and unsurprisingly been warming post LIA, that humans have caused some part of this (how much open to considerable debate as the science is not settled or particularly clear), that there is some chance of it being “catastrophic” warming in the future, a much larger chance that it will not be, and some chance that it will not warm further at all or even cool.
The rational thing to do is to continue to pursue the science, especially the accumulation of a few more decades of halfway decent data, until that science becomes a bit clearer, without betting our prosperity and the prosperity of our children and the calamitous and catastrophic perpetuation of global poverty and untold misery in the present on the relatively small chance of the warming being catastrophic and there being something we can do about it to prevent it from becoming so.
So far, if catastrophe is in the cards, the measures proposed won’t prevent it even according to those that predict it! In fact, it won’t have any effect on the catastrophe at all according to the worst case doom and gloomers. We could stop burning carbon worldwide tomorrow and if the carbon cycle model currently in favor with the CAGW crowd is correct (which I doubt) it would take centuries for the Earth’s CO_2 level to go back to “normal” — whatever that means, given that it varies by almost a factor of 2 completely naturally from glacial era to interglacial. In fact, according to that model the CO_2 levels will continue to go up as long as we contribute any CO_2 at all, because they’ve stuck an absurdly long relaxation time into their basic system of equations (one with very little empirical foundation, again IMO).
Again, I suggest that you reread the top article carefully. I actually do not think it is the best example of Monckton’s writing — a few people have noted that its tone is not terribly elevating, and I have to agree — but I sense and sympathize with his frustration, given the content of the article. There is a stench of hypocrisy that stretches from Al Gore’s globe-hopping by jet and his huge house and large car all the way to a collection of people with nothing better to do who have jetted to Doha to have a big party and figure out how to continue their quest for World Domination, hypocrisy with king-sized blinders that seem quite incapable of permitting the slightest bit of doubt to enter, even when bold predictions like those openly made in the 2008 report come back to bite them in the ass.
I myself am not a believer in CAGW. Nor am I a disbeliever. The only thing that I “believe” in regarding the subject is our own ignorance, combined with a fairly firm belief that there is little reason to panic visible in the climate record, and that is before various thumbs were laid firmly on the scales. Remove those thumbs and there is even less reason to panic.
My own prediction for the climate is this. We will probably continue to experience mild warming for another ten to twenty years — warming on the order of 0.1C per decade. It will probably occur in bursts — the climate record shows clear signs of punctuated equilibrium, a Hurst-Kolmogorov process — most likely associated with strong El Ninos (if we get back to where strong El Ninos occur — the last couple have fizzled out altogether, hence the lack of warming). In the meantime, we will without much additional effort beyond existing research and the obvious profit incentives drop the cost of solar power by a factor of four, and it will become at least competitive with the cheapest ways of generating electrical power. We will also have at least one major breakthrough in energy storage technology. The two together will cause solar to become more profitable than coal independent of subsidy, for much but not all of the world. Without anybody being inconvenienced or “doing” anything beyond pursuing the most profitable course, global consumption of carbon will then drop like a rock no matter what we do in the meantime.
Beyond twenty years I don’t think anybody has a clue as to what the temperature will do. I don’t even have a lot of confidence in my own prediction. It wouldn’t surprise me if it got cooler, especially if the Sun enters a true Maunder-style minimum. Nor would it surprise me if it got warmer than my modest prediction. But either way, I think roughly 500 ppm is likely to be the peak level of CO_2 before it comes down, and it may well fail to make it to 500 ppm, and even the catastrophists would have a hard time making a catastrophe out of that given 0.3 C of warming in association with the bump from 300 to 400.
We could make it more likely to cut off before 500 ppm — invest massively in nuclear power. Nuclear power is actually relatively cheap, so this is a cost-benefit win, if we regulate them carefully for safety and avoid nuclear proliferation (both risks, but less catastrophic than the inflated predictions of the catastrophists). But I don’t think we will, and in the end I don’t think it will matter.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Note that the italicized intro to this thread was actual Dr Brown quoting the rather ill- informed Pat Ravasio.
His answer to her is the NON-italicized portion. Her original post was in the comments to the Lord Moncton thread “OOPS”
Pat Ravasio on December 2, 2012 at 12:02 pm
So wait, you are saying that fossil fuels do not cause warming, but that if we shift away from them to clean energies, there is a risk of the earth cooling? Uh, could you just think that through and try agan?
I hope Pat has learned something new by hanging out around here.
Ah, if only the money was in Reason, and not in Sensationalism.
rgbatduke says:
December 3, 2012 at 4:12 pm
The global climate models stand refuted by the temperature record of the past fifteen years, in my view. A resumption of warming is the hope and prayer of the modelers, but there is no basis for such an expectation now that the principles of radiation physics are shown to be erroneously applied to our atmosphere. In short, the verdict is in on the GCM’s. What now is the reason for forecasting a resumption of warming?
I have no idea what this even means.
What I meant was that the models,which have applied the principles of the physics of radiation to model the response of our atmosphere to increasing CO2 in order to achieve their forecasts, have only achieved invalid results. So where is the problem? It must be an error in the application of the physics, because a fundamental error in the physical principles seems too unlikely. In other words, they goofed up.
Robert Brown says:
“it is almost certain that some fraction of that warming was completely natural, not due to human causes and we do not know that fraction — a reasonable guess would be to extrapolate the warming rate from the entire post LIA era, which is already close to 0.1 C/decade. ”
—————————————————————————————————————-
You are being quite liberal in your estimate of warming Robert. If you take the Central England Temperature record (the longest available) from 1659 to 2010 and insert a linear trend then the overall rate is not 0.1 C deg per decade but 0.25 C deg per 100 years or 0.025 C Deg per decade post LIA. And the human caused effect? – We’re back to bee digit magnitudes.
Cheers.
I disagree that we need to understand the climate sufficiently to model it, in order to predict climate changes.
I think we will at some point be able to predict climate change over timescales from a few weeks to a few decades from a small number of measurable factors.
The Indian government gave up on the global circulation models, because of their complete inability to predict monsoon conditions, and are now developing models that use measurable factors. Early indications are these models are showing promise.
There is huge economic value in being able to predict weather months to years in advance and this is where progress will be made in climate prediction, because of the economic imperative.
rgbatduke;
Another great thread Robert, you are a great writer and fantastic teacher.
I was wondering if you could expand on the CO2 doubling = +1 degree estimate a bit? As you know from past conversations, there’s no doubt in my mind that the GHE exists. But I do question the general estimate from two perspectives:
1. The temperature increase cannot be evenly distributed for three reasons:
a) SB Law requires that a given forcing (say 3.7 w/m2) will result in far less than 1 degree in the tropics and far more in the arctic regions…BUT:
b) The forcing itself cannot be evenly distributed since there is less upward LW in the cold regions of the planet, we cannot expect the same net forcing as in the warm regions due to a given change in CO2… AND:
c) Any additional energy that is retained by the planet will be redistributed from areas of high concentration to low, so even if we can resolve a) and b) above to we have any “known physics” that would be a useful predictor of how the temperature distribution would ultimately change from tropics to arctic regions.
2. The concept of forcing is (my understanding here, please correct me if I’ve gone astray) defined by calculating the “extra” downward travelling photons that would not have existed if CO2 had not doubled and subtracting from them the “extra” downward photons that would not otherwise exist (that’s roughly the IPCC explanation). The net equates to roughly 3.7 w/m2 which I am good with. Here’s the part I’m not so certain of:
If the sun’s radiance were to increase by 4 w/m2 at TOA, we could measure exactly that amount at TOA. We could calculate exactly via SB Law what the change to the earth’s effective black body temperature would be. But where do we “measure” the w/m2 from CO2 doubling? It doesn’t matter if the number is 1, 3, 5 or 15, it doesn’t exist at any single altitude in the atmosphere. It is a value comprised of infinitely small values spread across the atmospheric column. If this is the case, is SB Law even a valid calculation?
3. (I said 2, but I’m in sales, I can’t be counted upon for numerical accuracy) Further, how do these downward photons get to the surface to warm it? We often discuss the fact that CO2’s effects at sea level are overwhelmed by water vapour, and so are more pronounced at higher elevations where lower temperature squeeze the water vapour from the air and CO2 becomes proportionally more significant. But wait…if water vapour makes CO2’s effects insignificant on the way up… aren’t the same CO2 effects coming down running into a wall of water vapour that absorbs and re-radiates it? Does some get through to the surface to warm it? Sure. But all of it? Surely not? Most of it? Some of it? I’ve asked this question in the past, and gotten long explanations about warming at elevation plus lapse rate = warming at surface, but I haven’t found them all that compelling. At day’s end, if some of those downward photons don’t make it to surface in some quantity, there’s no warming (at surface) and I’m not understanding how this can happen with all that water vapour resisting LW (in both directions).
TIA!
by calculating the “extra” downward travelling photons that would not have existed if CO2 had not doubled and subtracting from them the “extra” downward photons
>>>>>>>>>>>>>>>
I meant downward subtract upward of course. fingers disengaged from brain….
Its all a belief system of course. I believe I will have another beer….
(some belief systems are easily verified)
Correctomundo, FrankK. There is no discernable human signal in any temperature record. None whatever. If there were, we would get beat over the head with it by the alarmist contingent 24/7/365. The rise in global temperature since the LIA has been the same, whether CO2 was low or high. Global warming has not accelerated. If anything, it has stopped, at least since the 1990’s.
This is the central fact that constantly gets glossed over and ignored. There is NO verifiable anthropogenic signal in any temperature record. The null hypothesis remains un-falsified.
So let’s pretend we’re all Captain Obvious, and think about what that means. There’s a conclusion there, hiding right in plain sight.
John Blake,
While RGB may decline to argue with you (although he proceeded to), I will. Look at the configuration of continents during the Permian, Ordovician, and most recent Proterozoic (before that the polar wander paths go over the edge) glaciations. Snow cone earths happened in many configurations.
Thanx Anthony for making this a post. Thanx Dr. Brown for taking the time to reply.
Very good essay by Dr. Brown. As close as anyone has gotten to my layman’s conclusions about the subject.
You know what I would love to see? Some good computer artist here develop a 1,000 x 1,000 cell grid, i.e., 1 million cells, and then, down in a lower corner, shade in the 280 and 391 cells representing respectively early and current atmospheric CO2 concentrations. Or maybe just shade in part of the bottom row. I’d just like to SEE what those proportions look like. If one could see them. The whole thing just seems like such a fantasy to me.
Blast you Dr. Brown. You can read, comprehend, and give long pertinent responses to comments faster than I can read them. I can’t even type and make sense as fast.
Thanks for the sanity, intellectual honesty, and scientific skepticism. I’ve very rarely seen these to this degree from anyone on any side.
One comment. If climate scientists are privately doubtful of the IPCC’s Summary for Policymakers, and the catastrophism in the MSM, let them say so publicly. Intellectual honesty demands it.
I think we will at some point be able to predict climate change over timescales from a few weeks to a few decades from a small number of measurable factors.
That’s very optimistic, since “climate”, as opposed to “weather”, hardly changes over that short a timescale, except when it does, sometimes abruptly and with no warning, as a chaotic fluctuation from one climate state to another. Or to put the issue another way, exactly what is “climate”?
This is not an irrelevant question — a large part of the bait and switch game of talking about “climate change” instead of “global warming” (once the globe stopped warming as predicted) is due to the lack of any sort of meaningful (objectively definable) difference between climate change and the normal variability of weather on any sort of short time scale. By confounding the two one can make any “extreme” weather event into “evidence of climate change” into “evidence of climate change due to Anthropogenic Global Warming leading to eventual catastrophe” when it is nothing of the sort.
Predicting actual climate changes — how could one even tell? Climate isn’t regional. Or is it? What is signal — real “changes in the climate” and what is noise — “irrelevant fluctuations in the weather due to random, unpredictable factors”? How can you even measure the difference when the signal is an order of magnitude less than the noise (as it is on timescales less than a decade in any given region)?
According to that good old standard of meaning, the dictionary, climate is weather in some location “averaged over some long period of time”. This means that climate change is by definition confounded with statistical noise in the weather over shorter periods of time. You can only tell if any given change is a climate change instead of a normal statistical fluctuation long after the fact, by virtue of the change being persistent.
Then there is the difficulty of the problem. Let’s ignore the full range of the multivariate complexity and stick with just one thing. There are well-known correlations between e.g. El Nino and La Nina conditions and probable annual weather variations relative to the floating “norm” (whatever it might mean) ranging from number of Atlantic hurricanes to expected rainfall or snowfall and temperature in the US Southeast. I live in North Carolina, and it seems like a relevant predictor for the state of affairs outdoors (whatever one calls it) in North Carolina.
Is that correlation weather or climate, more particularly, is that weather or climate change given that the very existence of the rule suggests that it is not a change, it is a normal expression of how the weather works?
Given that AFAIK, it is not possible to predict either the timing or the strength of the ENSO a decade out, given that weather/climate appears to depend on the particular present and recent past state of the oscillation over much of the globe, how accurate do you think the predictions of “climate change” could be? To make the question concrete, given your choice of the various temperature estimates for the period from 1979 to 2012 — RSS, GISS, HADCRUT, whatever — how would any simple “almanac” level model have predicted either the volcanic eruptions or the superstrong ENSO that is almost certainly responsible for the sharp bump in SSTs and global temperatures that occurred in the general vicinity of 1997-1998? Without this bump, the decadal predictions are horribly wrong, but I see no possible way that anyone could have predicted Mount Pinatubo or the 1998 ENSO effect in 1988, let alone 1978. Do you?
Just curious.
rgb
dabbio
I’d just like to SEE what those proportions look like. If one could see them. The whole thing just seems like such a fantasy to me.
>>>>>>>>>>>>>>>
I’ll be very interested to see rgb’s answer to this one, but I run into this question a lot, so here’s mine:
It isn’t simply proportions that count. It is scale. CO2 molecules don’t get “used up” and neither do the photons. A CO2 molecule can absorb and re-radiate an infinite number of times, it doesn’t wear out, and that is key to the rest of the explanation.
Instead of imagining it as a grid, imagine it as a round jar. Make the jar’s bottom 100 square millimeters and make the jar 100 mm high. The jar has a volume of 10,000 mm cubed. Imagine filling the jar with 9,996 yellow bb’s and 4 blue bb’s. Since this is a make believe jar and make believe bb’s, they exactly fill the jar. The chances of you seeing a blue bb through the sides of the jar are tiny.
OK, so make the yellow bb’s invisible. Now you can see the 4 bb’s suspended in the jar. I know what you are thinking. So what? Doesn’t that just prove the point? Four specs of blue in the entire jar?
This is where the atmospheric scale comes in. Imagine 100,000 jars stacked up in a single column 10 kilometers high. Yes, from the side, all you would see is a spec of blue here and there. But there’s now 400,000 blue bb’s stacked up in that column. Assuming they are evenly distributed, a photon going straight up from bottom to top would hit a CO2 molecule 4,000 times.
Well, assuming it was absorbed and re-radiated straight up it would be 4,000 times. If you assume that instead sometimes get re-radiated up and sometimes re-radiated down, a lot more than 4,000 times.
rgbatduke says, December 3, 2012 at 7:51 pm: “According to that good old standard of meaning, the dictionary, climate is weather in some location “averaged over some long period of time”.”
========================================================
This definition is not old, it is relatively new and warmists like it understandably, because they can just call any deviation from this “average” a “climate change”.
In reality, if we look up in the Webster’s Revised Unabridged Dictionary (1913 + 1828) (http://machaut.uchicago.edu/?resource=Webster%27s&word=climate&use1913=on&use1828=on), we will find this definition there: “Climate 2. The condition of a place in relation to various phenomena of the atmosphere, as temperature, moisture, etc., especially as they affect animal or vegetable life.”
No mention of “average” there. Because back then and probably all the years before people were sane enough to NOT put temperatures and other weather phenomena at different locations together and calculate a “global average”. The idea of a “global average temperature” representing “global climate” is absolutely crazy according to the definition I quoted. “Global climate” is nonsense as well, sorry, dear climate scientists. The idea of a “warmer year”, because for a few days the temperature was a little bit higher is crazy, too.
Imagine, if the medical science defined health as an average of different body parameters. Like average heart beat frequency for 30 days. Or average defecation.
Go ahead, dear climate scientists, fool us all the time.
D Böehm says:
December 3, 2012 at 6:26 pm
Correctomundo, FrankK. There is no discernable human signal in any temperature record. None whatever. If there were, we would get beat over the head with it by the alarmist contingent 24/7/365. The rise in global temperature since the LIA has been the same, whether CO2 was low or high. Global warming has not accelerated. If anything, it has stopped, at least since the 1990′s.
———————————————————————————————————–
Mr Boehm no correction necessary, I agree the trend over that long period is natural at 0.25 C deg per 100 years since the LIA – precisely what I said. The human contribution is as I described above – a bees willie – indiscernible if its there at all..
If you want to talk about individual ups and downs in the temp graph then I always point to my warming friends how come the same Central England temp record shows a rise of over 2 C deg over 40 years from the end of the 17th Century to the start 18th when industrialisation was virtually nil with no rise in CO2 level. And yes CO2 has gone up over the last 16 years and temperature has flat-lined. The AGW theory is well and truly busted.
At day’s end, if some of those downward photons don’t make it to surface in some quantity, there’s no warming (at surface) and I’m not understanding how this can happen with all that water vapour resisting LW (in both directions).
— is heated from the inside at a constant rate. In a vacuum surrounded by the perfect absorber (or in actual space surrounded by a near-perfect absorber in the form of a 3K vacuum), it thus reaches a temperature that is completely determined by Stefan-Boltzmann, such that the rate of its outward radiation precisely balances the rate of internal heat production. Interestingly, this temperature doesn’t even depend on what the sphere is made of — its actual enthalpy is more or less irrelevant. Call the temperature of this sphere 
.
.
There is no “warming” at the surface due to the photons per se. The warming is due almost entirely to insolation or (a bit) the other actual source(s) of heat. What the CO_2 (or other GHGs) does is act almost exactly like a space blanket and reflect part of the outgoing radiant blackbody energy back, slowing the cooling. The surface thus spends more time warmer than it would without the back radiation, resulting in an elevation of the mean temperature.
Back when I was doing a thread on John Nielsen-Gammon’s blog site in response to part of his and my discussion, as well as a long annoying discussion I was having with Mr. Sky Dragon (Olson), I undertook to write a very simple pure blackbody model that shows how putting any sort of perfect absorber/perfect radiator interpolated layer between a surface being heated at a given more or less fixed state and “space” — a zero-temperature perfect absorber surrounding blackbody — raises the temperature of the surface in a fairly predictable and understandable way.
The model works like this. The central perfect black body — let’s assume a sphere of radius
Now we prepare a second sphere identical to the first one, only we surround it by a thin shell that is a perfect conductor of heat and also a perfect blackbody. To avoid conduction from the inner sphere to the shell, we will leave a small vacuum gap on the inside between the shells, and we will make the outer radius of the outer shell whatever you like that is larger than the inner sphere.
Now radiation from the inner sphere is perfectly absorbed by the shell. The shell warms. As it warms it reradiates energy according to Stefan-Boltzmann both back in towards the sphere and outward. If its radius is only a bit larger than that of the sphere, it will have to warm pretty much to the temperature that the inner sphere had without it in order to balance the net heat production inside of it.
However, when it is radiating this amount of power outward it is also radiating almost exactly this amount back in at the original sphere.
The inner sphere needs to lose the same power it did before. However, now it has just about exactly that much power radiating back down on it from the shell (when the shell is in net power equilibrium with the only actual source inside of its outer surface). It therefore has to radiate twice as much power to remain in equilibrium. It will do this when its temperature is
Voila! We have the greenhouse effect! Or rather, an upper bound estimate of it, as the Earth is not a uniformly heated perfect blackbody, neither is the interposed shell of blackbody gases, which are in thermal contact with the Earth’s surface, and which are not perfect conductors. But the idea is now clear, and the simple model suffices to demonstrate that it is quite impossible to interpose an absorber/isotropic reradiator layer between the Earth’s surface and infinity and not raise the temperature of the Earth’s surface, on average, to where it can lose both the straight up insolation and the reflected backradiation in each diurnal cycle.
Note also that I make no claims that this is an accurate description of the full, far more complicated, way that the Earth actually absorbs and loses heat, only that it is (if you meditate upon it for a day or so) a process that is verified to actually exist by direct TOA and BOA IR spectroscopy, in a spectral pattern that positively proves the interpolant layer to be greenhouse gases (primarily water, ozone, and CO_2 but you can identify a few other bands as well corresponding to e.g. ordinary oxygen and/or nitrogen) and that cannot possibly fail to produce average warming of the surface compared to what would result in the absence of that layer.
Note well that one cannot do better than optically opaque, and CO_2 is indeed an optically opaque layer many times over. One therefore expects the warming to be almost completely insensitive to CO_2 concentration — the additional warming is not a direct effect, it is an indirect, second order effect resulting from changes (broadenings, IIRC) in the absorption spectrum. This also says nothing whatsoever about nonlinear complexity, water vapor feedback (either way), the complications introduced by geometry, surface albedo, axial tilt, and the ocean. It is a toy model that demonstrates that the GHG-moderated GHE, as verified by actual IR spectroscopy, does indeed warm the Earth’s surface relative to the similarly insolated moon and provides some insight into how it works without violating any of the laws of Thermodynamics (a common, silly assertion of those that wish to claim that the GHE doesn’t exist at all).
Regarding the 1.2 C — sorry, I can’t really help you there. It’s a number that surfaces a lot in discussions of the CO_2 linked GHE, and I assume that it arises from an explicit computation of the spectral broadening of the CO_2 lines with partial pressure, plus a certain amount of English that is, yeah, often linked to the DALR and radiation from the layer in depth where the atmosphere starts to become less than opaque to the radiation in the relevant band. But have I myself computed it, or even verified the computation? I have not. I’m so ashamed, but — remember, this is a hobby for me as well, and I have a full time day job, a family, and a baby company in case I actually have any time left over. I’ve spent way too much time on my hobby today as it is…;-)
OTOH, I did talk about your smaller log-scale estimates with John N-G (as they seemed pretty reasonable to me) — his reply was that the current climate models do indeed balance mostly cancelling numbers that are much larger than the final result. That is, there are much larger gains from the GHE (so that the base variation of the log scale is much larger in the first place), but they are balanced by negative/cooling effects (e.g. aerosols, albedo variation) that are almost as large, so that the net warming is much smaller. At least, that’s the way I recall it. So the differential warming anomaly would NOT follow a moderate log scale, it might be much larger. That is (for example) we might be looking at 2.5C of anthropogenic cooling and 2.8 C of anthropogenic warming to produce 0.3C of net temperature anomaly, so that a ten percent change in the warming might double the anomaly. As he put it, the Earth might actually be cooling now if it were NOT for CO_2, so the CO_2 linked effect might be much greater than “just” the observed anomaly.
Do I buy this? Not entirely. For one thing, modeling any small effect that results from cancellation of two larger numbers is numerically a dicey proposition, because the result can easily leave you deep in the error bars of the large numbers. Just as true evaluating spherical bessel functions with forward recursion, actually. Statistically, one is stating that there is a lot of covariance between heating and cooling components of the models (so no wonder they are not too stable or too accurate). Or maybe this is an oversimplification, I don’t really know.
I’d love to find out, eventually, but to go any farther in this at this time would require me to work through all of the details, and the only thing that would justify this would be if it were part of my job, not a hobby. Just thinking up clever little arguments like the one above takes a fair bit of time, but nothing like the time required to understand a numerical effort to solve the world’s most difficult computational problem well enough to comment on its details. Maybe if my baby company grows to become a great big grown up company and makes me a pile of money I’ll come back to it.
Sorry,
rgb
Duster says:
December 3, 2012 at 12:35 pm
“It is simply not true and makes a secular “original sin” assumption that is logically and empirically unsupported.”
A necessary ingredient for any religion.
Mike Borgelt says:
December 3, 2012 at 4:22 pm
“Lots of luck on the 4 x fall in solar costs…”
So true. When you’ve spent 50+ years waiting for “the big breakthrough” hyped continuously beyond rational thought, you tend to become a little jaded. We’re just not going to get there pounding our heads against the same stone wall. Some radical new insight is going to be required, and who can predict when such an epiphany will occur, if ever? Same goes for fusion power. It’s all pie in the sky for now and any foreseeable future.
I’d just like to SEE what those proportions look like. If one could see them. The whole thing just seems like such a fantasy to me.
David’s reply is pretty good. The point is that (quite seriously) the atmosphere is optically opaque in the CO_2 and water vapor bands in the relevant IR part of the spectrum many times over. Basically NONE of the photons emitted from the surface in these bands make it through to space, not without being scattered many, many times. What one ends up with is basically a diffusive process (from the point of view of the photons) that redirects a large fraction of the outgoing radiation in these bands back to the surface and significantly slows the rate of heat loss by the surface compared to what it would be if the photons just went straight out to infinity the very first time they were emitted. I gave a much simpler (non-photon) explanation involving optically opaque unit emissivity pure blackbodies up above that is actually even simpler if not as faithful. And even the pure scattering description is not terribly accurate because the molecules cool more the higher one is in the gas column because of adiabatic lapse, so that the assumption of the interpolant layer being a perfect conductor at a uniform temperature isn’t even close to being correct. It absorbs or otherwise picks up heat at the bottom at one temperature, and loses it at the top and an entirely different one, with a variety of mechanisms establishing and maintaining the variation in between. Well, it doesn’t even “lose it at the top” as if the top is a surface. It loses it out of a volume with depth where the atmosphere stops being completely opaque. This top layer, however, more or less defines the top of the troposphere.
It’s all really pretty complicated, but not too complicated to understand, at least enough to see that it isn’t bogus.
rgb
The non-parsing formula was the fourth root of two times T_0 = 1.19 T_0, sorry. Grumble grumble no edit/preview feature in wordpress grumble.
rgb
That’s it Dr. Brown, now you’ve gone and done it! You clearly have way too much common sense for Duke. Please move your office to NC State.
Go Wolfpack!
Sorry, although I’ve a nephew who graduated from NC state in engineering, I’m a double Duke alum faculty person, not likely to change before I’m dead. I actually spent the weekend at Marshallberg and Harker’s Island with friends who are Woofers. We had a great time together — but I still wouldn’t drink my beer out of their Wolfpack Tervis Tumblers, sorry…;-) We did, however, enjoy mutually disrespecting the Tar Heels — it’s easy for Devils and Wolfs or Pirates (down in ECU country) to find common ground as long as UNC remains as obnoxious as it clearly is…:-)
So sure, Go Woolfs, as long as they aren’t playing Duke!
rgb
We do know some things; for example, below about 160 ppm CO2 in the atmosphere, life as we know it begins to end. We geologists know that the earth has been extraordinarily efficient at extracting CO2 from our atmosphere and oceans, in the amount of trillions of tons, from day dot. The ice cores from Antarctica and Greenland, although perhaps arguably dispositive, indicate we got near the termination point for long periods of time. As a result, I don’t fear CO2 “zooming” up to levels like 1000 ppm; life has prospered at levels far above that. I dread the opposite. A return to LIA conditions, along with cessation of manmade CO2 emissions, could be a very bad thing (for more than one reason).
On another point, I agree that a few years of temperature stasis means nothing (the historical picture we have of temperature trends is something that maintains over periods of a few hundred years, e.g. the Dark Ages, the Medieval Warm Period, the Little Ice Age, etc. However, as I understand the models the warmists depend on, every single additional molecule of CO2 adds a fraction of a degree to the earth’s temperature. Therefor, it is impossible that the earth’s temperature can exhibit a standstill of five years, much less 15, given the nearly exponential increase in CO2 we have experienced over the last 15 years. Therefor, their models don’t work, and those who continue to push their results are shown as charlatans, and should be defrocked and at least, have any service with the US Government terminated with prejudice.
John West says: December 3, 2012 at 12:03 pm
quote
Ever hear of bacteria? Oil is biodegradable.
unquote
Yes, of course. How quickly? And how quickly was it biodegraded in the past — not just in oil seep areas but generally? Has the added oil spill from fossil-fuelled civilisation increased the ability of the ocean biota to process oil? It seems logical that it will have, so the problem should be reduced as time goes on.
The models seem to ignore biological responses: if you enjoy seeing oceanic albedo change on a large scale, Google Emiliania huxleyi and check images. I wonder how _that_ turns up in a model.
JF
George Lawso9n says: December 3, 2012 at 12:22 pm
quote
I doubt whether anyone would support your stupid statement that you’ve seen oil smooths completely cover the whole of the Mediteranean.
unquote
My apologies, I meant that I had seen smooths from end to end, not that one smooth extended from end to end. I have flown over the Med frequently over the years — smooths, large smooths off Cyprus are very common now, and the Western end has huge rivers of smooth flowing out from all the towns and villages. I appreciate that it’s not a nice thing to contemplate, but it’s there and calling me stupid wil not get rid of the facts.
quote
I suspect that is part of the warmists scaremongering again. Just look at the sites of major oil spills around the world and see how they have very quickly returned to their natural state within a very short space of time.
unquote
Why I am assumed to be a warmist is puzzling. Perhaps you have not thought through the reasoning behind the CO2 scare: ‘it’s warming and it’s CO2.’ My argument would be ‘it’s warming and some of it is CO2, some is black carbon, some of it is agricultural albedo change, some may be oil spill mediated changes in the ocean surface.’ Now follow the logic. If it is warming (oops, was warming until recently) because of more than one cause then the CO2 portion of the warming is reduced. CO2 sensitivity is low and there is no need to close down civilisation. Dr Hansen has flirted with this fact in a paper called IIRC Global Warming In the 21st Century.
As an exercise you also might try looking at the HADCRUT graphs and the Climate Audit posts about the Folland and Parker bucket correction. Then look at ‘why the blip’ as I suggested earlier. The sea temperature blip in the 1940-45 period is real and unexplained. Try to think of a reason other than the entirely possible ‘it was natural’.
JF
Duster says: December 3, 2012 at 12:35 pm
quote
The volume of oil seeping from natural sources sources is far greater than human linked “catastrophes.” Studies in the Gulf have imaged steady minor seeps over square miles. The Exxon Valdiz in Alaska and more recent events in the Gulf of Mexico are geographically focused – point locations – that magnify the apparent seriousness of the events.
unquote
One of the ironies of the scare stories of the Gulf leak was that one can easily find images of seeps in the same area. The press didn’t bother with that basic research. However, please look at
http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/peril_oil_pollution.html
and you will find that your assertion re amounts is incorrect unless you confine your statement strictly to oil-spill accidents — that is ship sinking, oil well blow-outs etc..
NASA’s figures: Big spills, 37, routine maintenance 137, down the drain 363, up in smoke 92, offshore drilling 15, natural seeps 62. That’s millions of gallons (US) and was the state of things in 1994. Since then all the figures except seeps* will have increased enormously as the industrialisation of the globe continues — I bet there is a larger proportion of oil coming down Indian and Chinese rivers by a factor of ten.. Seeps are a small proportion of what’s going on.
quote
Pollution is a serious problem, but we really need to know the magnitude of our own outputs, before we can do something useful about them. It is a profound mistake to simply conclude that nature would be benign if only people were tidier. It is simply not true and makes a secular “original sin” assumption that is logically and empirically unsupported.
unquote
It is also a mistake not to do a little research before forming an opinion. Civilisation is making a difference to the world whether we like it or not, and oil pollution is one of those differences. NASA, again, claims that the oily run-off from the roads of a city with 5 million inhabitants is equivalent to a major tanker disaster. Drop by drop is the problem, may be the problem, but it passes us by. HTH.
JF
*By drilling near seeps the oil industry is reducing their output.