The new novel Solar by Ian McEwan, Britain’s “national author” (as many call him) tackles the issue of climate change. I should perhaps start my review with a disclosure: I’m a long-standing fan of McEwan and have read all of his novels, and I am also mentioned in the acknowledgements of Solar. I met McEwan in Potsdam and we had some correspondence while he wrote his novel. Our recent book The Climate Crisis quotes a page of McEwan as its Epilogue. And of course I’m not a literature critic but a scientist. So don’t expect a detached professional review.
In interviews McEwan describes his difficulties in approaching the topic of climate change: “I couldn’t quite see how a novel would work without falling flat with moral intent.”
One solution is that he makes his protagonist who tries to “save the world”, the Nobel laureate physicist Michael Beard, thoroughly pathetic and unlikeable. (Actually quite unlike any scientist I know, but certainly less boring than us at Realclimate.) The only redeeming feature of Beard is his sarcastic humor. When his business partner is worried that claims of global warming having stopped will ruin their grand solar energy scheme, Beard (after expertly refuting the “no warming since 1998” myth) retorts:
Here’s the good news. The UN estimates that already a third of a million people a year are dying from climate change. Even as we speak, the inhabitants of the island of Carteret in the South Pacific are being evacuated because the oceans are warming and expanding and rising. Malarial mosquitoes are advancing northwards across Europe… Toby, listen. It’s a catastrophe. Relax!
This is McEwan’s funniest book. The humour in it is another way around the moral gravity of the subject. In an interview he said:
The thing that would have killed the book for me, I’m sure, is if I’d taken up any sort of moral position, I needed a get-out clause. And the get-out clause is, this is an investigation of human nature, with some of the latitude thrown in by comedy.
Half-way through the novel Beard gives a riveting speech on climate change to an auditorium full of pension-fund managers (representing 400 billion dollars of investments) – a speech that I’d be almost tempted to steal and use verbatim myself at some occasion. But what could have been tedious – a whole lecture embedded in a novel – is turned into a hilarious scene where Beard is engaged in a losing battle with his bowels, trying to continue speaking while swallowing down “a fishy reflux rising from his gorge, like salted anchovies, with a dash of bile”.
McEwan showing off that he can write such a speech better than a scientist is reminiscent of his novel Enduring Love, to which he appended an entire scientific paper about a psychological disorder (De Clerambault’s Syndrome) that allegedly inspired the book. Later he admitted this “paper” was part of the fiction. He’d even submitted it to a journal, but one of the reviewers smelled a rat.
McEwan’s deep (and often playful) affinity to science is one of the hallmarks of his writing and of course one reason why I like his novels. The other is his stunning power of observation; he seems to be reading people’s minds, cutting right through their delusions to get to the deeper truths. In that, his analytic work as a writer resembles that of a scientist.
McEwan is a forceful rationalist and well-versed in science culture, and his witty observations on that are a big part of the fun of his books. In Solar, for example, he pokes some hilarious fun at the social constructivists. Beard chairs a government committee to bring more women into physics, and a social scientist on his committee introduces herself with a speech on how a particular gene is not discovered by scientists, but is rather a social construct.
Beard had heard rumours that strange ideas were commonplace among liberal arts departments. It was said that humanities students were routinely taught that science was just one more belief system, no more or less truthful than religion or astrology. He had always thought that this must be a slur against his colleagues on the arts side. The results surely spoke for themselves. Who was going to submit to a vaccine designed by a priest?
This develops into my favourite subplot. At a press conference of his committee, the journalists are “slumped over their recorders and notebooks” and “depressed by the seriousness of their assignment, its scandalous lack of controversy”, as “the whole project was lamentably worthy”. Beard makes some fairly harmless remarks about the efforts of bringing more women into physics perhaps reaching a ceiling one day, because they may have a preference for other branches of science. The social constructivist explodes (“Before I go outside to be sick, and I mean violently sick because of what I’ve just heard, I wish to announce my resignation from Professor Beard’s committee.”) Predictably, that makes the predatory journalists spring to life, and in the following McEwan spins a completely credible story how Beard’s remarks turn into a media storm where Beard’s love life is dragged into the tabloids and his “genetic determinist” views are linked to Third Reich race theories. One journalist, “more in the spirit of playful diary-page spite”, calls him a neo-Nazi.
No one took the charge seriously for a moment, but it became possible for other papers to take up the term even as they dismissed it, carefully bracketing and legalising the insult with quotation marks. Beard became the ‘neo-Nazi’ professor.
McEwan knows what he is writing about: he became subject to a media storm about his Islam-critical views a few years ago. I read Solar in February (thanks to an advance copy that the author had sent me), in parallel with the unfolding surreal, but real-world media campaign against IPCC, and found that McEwan dissects the mechanisms beautifully.
McEwan says that the idea to make a Nobel laureate the main character of his new book came to him in Potsdam, when attending the Nobel Cause Symposium organised by our institute in October 2007 (and on page 179 his hero Beard returns from a conference in Potsdam). At the time I discussed with him whether this wouldn’t be a good topic for a novel: humanity facing an existential threat that is well-understood by its scientists, but largely ignored by a population who prefers to delude itself in creative ways about the gradually unfolding disaster. McEwan responded: everything there is to say about this situation has already been said by Thomas Mann in his novel Death in Venice.
I’m glad he tackled the topic of climate change nevertheless. It’s McEwan at his best. Intelligent, funny, and full of insights. Read for yourself!
Link: Here is McEwan speaking about Solar (and about his views on climate change) in a TV interview.
“let me clarify: i have read claims that it was up to 4 degrees warmer IN PARTS of the northern hemisphere.”
In parts of the northern hemisphere, it’s been 6C warmer and more.
North polar regions, for example.
http://data.giss.nasa.gov/gistemp/graphs/
Check the section “Comparison of 2010 Temperature to the Two Other Years with the Warmest Annual Means”
North America had a large section 6.8C warmer than average.
“THAT is not a an Appeal to Authority, unless you mean “I trust their judgement, therefore they are right.””
Shall I show you again:
“XYZ has said this is true, and they’ve been right many times before, they study this and they produce treatise that stand the test of peer review of similarly educated people. I trust their judgement.”
This is an appeal to their authority based on what they’ve been authoritative about in the past.
In neither past nor present case have I exhaustively proved their veracity and I’ve mostly relied on others who are also learned in the same sphere (also an appeal to their authority: I have not checked their work either).
So in what way is this NOT an appeal to authority?
In what way is that NOT “I trust them therefore they are right”? I have merely added WHY I trust their judgement. But it’s still an “I trust them therefore they are right”.
“But I thought – maybe I misunderstood you – that you were saying that we only need 6 or 7 doublings of CO2 to get from an Earthlike to a Venuslike atmosphere by some measure, such as the amount of CO2.”
No, Patrick: you only need 6-7 doublings to get our atmosphere (which contains gas that produces pressure up to 1 atmosphere) to Venus’ atmosphere (which contains gas that produces pressure about 90 atmospheres).
That is what I’m saying.
And that we have almost no CO2 is irrelevant because all gasses produce pressure and therefore if pressure is the reason why Venus is hot, then separating out one trace gas on Earth as the only standard to measure pressure is ridiculous.
What would happen if you used helium instead? Then earth would have NO temperature above the ~240K radiative transfer would have and Neptune would have infinity surface temperature.
Earth: 0 pp from He.
Neptune: > 0 partial pressure from He.
Any number / zero = infinity. = infinite doublings = double infinity temperature from pressure.
So why is Motl ignoring all other gasses in our atmosphere? They produce pressure just as well as CO2 does on both planets.
Of which we have 1 atmosphere pressure of. And Venus has 90.
6.x doublings.
re 40
Spencers super-secret new paper might be the one recently outlined at WUWT:
http://wattsupwiththat.com/2010/05/07/spencer-strong-negative-feedback-found-in-radiation-budget/
Not very impressing, but maybe worthwile an expert’s comment for the public (not yet seen anywhere).
For my own interest I am attempting some simple modeling calculations.
I’d be grateful if I could be pointed towards some on-line source of information on what is known about the dynamics of atmospheric carbon dioxide.
For example, if I released x tonnes of carbon dioxide into the atmosphere over a very short period, how long would it be until only x/2 tonnes of my release remained in the atmosphere?
WC 487,
1. Mostly Europe with some spots in China and Latin America.
2. No, it was cooler than now.
Frank Giger says, “That’s a lot of water to heat up, and undersea ridges and hot spots in the crust just ain’t gonna cut it.”
Yup! However, this is a recurring zombie argument in the denialosphere, where facts are seen as mere encumbrances to creativity. Frank, given your free-market bona fides, I wonder if you would have more luck engaging the denizens of this benighted enclave.
Phil, Hank, Ray,
thanks so much. i’ll read up from your links.
Hank, to answer your questions:
saw the “4 degrees”, not surprisingly, on WUWT:
“The idea of a medieval warm period was formulated for the first time in 1965 by the English climatologist Hubert H. Lamb [1]. Lamb, who founded the UK Climate Research Unit (CRU) in 1971, saw the peak of the warming period from 1000 to 1300, i.e. in the High Middle Ages. He estimated that temperatures then were 1-2 ° C above the normal period of 1931-1960. In the high North, it was even up to 4 degrees warmer. The regular voyages of the Vikings between Iceland and Greenland were rarely hindered by ice, and many burial places of the Vikings in Greenland still lie in the permafrost.”
http://wattsupwiththat.com/2009/11/29/the-medieval-warm-period-a-global-phenonmena-unprecedented-warming-or-unprecedented-data-manipulation/
i notice the’s an indication of a footnote after the rather bland statement about hubert lamb, but then there are none after the substantive (and amazing) claims. i also notice that there aren’t actually any footnotes on the page – just indications of them.
Titus (#498) (and any others wondering similar things),
Comments in moderation occasionally get lost, for whatever reason. Maybe someone pressed the wrong key, maybe who knows. Asking why it was not posted is usually a waste of your time and that of others, for two reasons. First, a brief look at some of the stuff that gets posted here suggests the moderators don’t go in much for silent censorship in any case, so if you were mature and to the point there’s all the less reason to think you were censored. Second, it’s a busy comment queue moderated by busy people who cannot be expected to go back and fish out comments that got lost by mistake. (Though IIRC they have done so on a few occasions.) It’s better just to grit your teeth and repost what you wrote. If you get in the habit of posting long careful comments, you may want to copy-paste-save them in your favorite editor…
On medieval warming, here’s a source that shows that ice cover in the Swiss Alps in 2003 was at a 5,000 year low:
http://www3.interscience.wiley.com/journal/114125034/abstract
I found this when some clown commenting on the letters blog of The Australian pointed to a German newspaper article quoting one of these authors (Suter) as saying “climate was warmer between 3000 and 1750 BC, in Roman times, and in the late Middle Ages”. My high school German isn’t good enough to check that source but funny how this research paper in English contradicts that claim — if it was meant to mean warmer than now (not clear to me that the newspaper report says that). There is a vast amount of garbage spewing about the net. It always pays to check these things. And call a lie a lie when you spot it.
Martin, a quick google turns up two possible starting points:
http://www.waterencyclopedia.com/Bi-Ca/Carbon-Dioxide-in-the-Ocean-and-Atmosphere.html
http://en.wikipedia.org/wiki/Carbon_sink
# 489 “The key to Science is my ability to reproduce your experiments, or to come up with a similarly reproducible experiment that invalidates your results. Science doesn’t care one whit how many papers you publish, who reviewed them, what journal published them, P’s, h’s and D’s after your name, or if you brush and floss your teeth after each meal. Science only cares that if I wanted to, and if I had the time and money, I =could= derive all of their findings from whatever depth of First Principles I can get around to deriving.”
Nonsense! Not even worth deconstructing. Irrelevant to the science of climate change.
But apologies for saying previously “You are wrong” what I should have said was “Your argument is wrong”.
I do say that I would never appeal to you as an authority on scientific method or logic.
“Asking why it was not posted is usually a waste of your time and that of others, for two reasons.”
And also that comment can dissapear likewise.
Three! *Three* reasons not to ask why. Among which are such diverse reasons as…
[Response:
:)
]
Oh, I’ll come in again…
” In the high North, it was even up to 4 degrees warmer. ”
In the high north in 1998 it was nearly 7 degrees C warmer.
Completely Fed Up, thank you.
I was hoping for something with quantitative data on the half-life of a dollop of carbon dioxide injected into the atmosphere, with information on the measurements or experiments that provided the data. The references you kindly gave discuss the various destinations of atmospheric carbon dioxide, but without much in the way of quantitative data on the timescales of these transfers.
I wonder if the radioactive carbon generated in the atmosphere by nuclear weapon tests has been studied to give information on the dynamics of atmospheric carbon dioxide levels.
Martin A:
http://www.google.com/search?q=lifetime+atmospheric+carbon+dioxide
Of the first four or five hits, try everything but the “John Daly” link.
Wikipedia’s not bad; the other links are to recent science papers.
Then try the same search in Google Scholar, always a useful comparison; this is since 2007:
http://scholar.google.com/scholar?hl=en&q=lifetime+atmospheric+carbon+dioxide&btnG=Search&as_sdt=2000&as_ylo=2007
“487
Walter Crain says:
11 May 2010 at 4:37 PM
1)what is the current thinking on the geographic extent of the “medieval warming period”?”
The geographic extent of a warming period in the first half of the last millenium depends on what years you consider the warming period to exist in.
It moved.
When N America was experiencing it, Europe was cold. When Europe was experiencing it, Russia was cold. And so on.
Therefore any warm period in a geographical location could be called “medieval warming period” but it was a cold period elsewhere.
When you average all areas through time, the MWP mostly disappears.
If you pick regions and plot them all on separate lines on the same graph, you can see a wider “MWP” that moved around a bit, but wasn’t on average all that warm.
So you need to answer “where are you considering the MWP to exist” and then your question can be answered. Without that, you can make up any answer you wish and even state quite correctly that there WAS NO MWP (because you could just move from one region that was cool to the next cool one).
“I was hoping for something with quantitative data on the half-life of a dollop of carbon dioxide injected into the atmosphere”
That has been posted here several times, Martin. And it’s part of the IPCC report too:
http://www.ipcc.ch
There isn’t one half-life because CO2 gets taken out in varying ways and they reach an equilibrium at different rates and to different levels.
The two links I gave show references to many papers. Several of them deal with different mechanisms. The IPCC summarises the overall effect.
Inclusion into rock strata, for example, is the real end-pint of CO2 but that takes thousands of years to reach “half life”. Soaking into the ocean is of the order of centuries/decades depending on whether you’re going to be worried about it coming back up any time soon.
IIRC, 1000 year residency time of 90% and then slow degradation beyond that is a (possibly high end) rule-of-thumb. 50% will disappear much sooner, but that exhausts the ability of that process to “eat” carbon.
“I wonder if the radioactive carbon generated in the atmosphere by nuclear weapon tests has been studied to give information on the dynamics of atmospheric carbon dioxide levels.”
Compared to the role cosmic rays have in the process, nuke testing doesn’t do much to the signal.
I find it odd how nuclear weapons are derided with “one volcano matches a thousand nuclear warheads” get, in a different context, “nukes created a lot of radioactive carbon from ordinary carbon from 50 years ago!”.
Here’s something of interest to the Venusian
http://www.pnas.org/content/early/2010/04/26/0913352107.abstract
As the authors point out, the efforts to “limit global temperature increase to 2 degrees C by 2100” all ignore the longer-term effects of fossil fuel combustion over the next three centuries. Such a target is thus fairly meaningless – and to stabilize the climate at 2C? That would require a far more focused effort.
It should be obvious by now that the only plausible method for stabilizing the global climate is to entirely eliminate fossil fuels from the energy mix – but getting politicians and fossil fuel lobbyists and academic and media institutions to actually admit that basic fact is most difficult. Tobacco smoking causes cancer, HIV causes AIDS, fossil fuel combustion causes global warming – and the “clean, low-tar cigarette” campaign is not any different from the “clean, low-tar coal” campaign – both campaigns are run by the same people, in fact.
FCH, by your formal (I suppose) definition of the appeal to authority fallacy, i.e. “everything XYZ says is true” or the reconfiguration “XYZ says it therefore it must be true,” NO ONE on this site is using appeals to authority.
NOBODY.
So have fun being right about that completely moot point.
People are saying “XYZ is more credible than most people because of their experience and prior demonstrations of understanding.” Is that a logical fallacy? People are saying “XYZ is more credible on this issue than ABC because when you compare their track records on related issues, XYZ is much more often proven right.” Is that a logical fallacy?
No. No it is not. Because judgments about how much credence to assign someone’s position are not T/F logical judgments. It’s more like probability than logic.
So enjoy your certain knowledge that you’re correct about your strict definition of “logical fallacy,” but NEVER NEVER effing bring it up again unless someone has actually said something to the effect of “XYZ has said so, and therefore and with no other support whatsoever I declare it to be true.”
Patrick I am reading your post which is tough going. Actually once i drew the relevant pictures it was pretty clear. Too bad we can’t post figures on RC. They’re worth a thousand words.
And is the motivation for all this to explain to me how a pure CO2 atmosphere would vary with the amount of CO2?
I’m not really following this very well. IF Opt = optical thickness and Optk = your threshold.
you’ve got log(Opt) ~ log(X) so I would say that Opt ~ X , no? Then the trick is to explain how to get an optical thickness that rolls over into log(X) because of the properties of the absorption spectrum of CO2? I’ve read a little bit of this random band model that rolls over into sqrt(X) for larger X. But I don’t know how all this ties together.
I’m also unclear as to how to go to optical thickness that you see in elementary expositions: T_{surface}^4 = (1+Opt) T_{e}^4 , which contains no information on frequency. I guess the idea is that the optical thickness in that equation is the optical thickness for the relevant wavelengths and you more or less ignore wavelengths that aren’t getting absorbed?
A bit tired of all those “formal logic” comments.
In deductive logic there are proof rules and axioms. One derives theorems from the axioms by applying the proof rules. That’s it, provided the axioms and accepted and the proof rules are sound.
But science proceeds via inductive logic, using probability and statistics to determine the likelihood of an hyposthesis given the data and also to compare hypotheses given the data. Begin with E.T. Jaynes’s “Probability Theory” book.
“Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so.”
Douglas Adams quoted by Gavin Schmidt in Climate Change Picturing the Science. See also Dunning-Kruger effect.
For example, I respect my doctor’s opinion because he knows more than I do, not because he’s a mythical embodiment of infallibility. He also knows enough to refer me to a speci alist when there’s a problem outside his area of expertise. But then thinking that way is probably obvious to anyone but a sophist or an acolyte of wingnut punditry.
CCPTS is pretty good reading by the way.
On another front, E. O. Wilson is apparently taking a new approach to science through fiction with Anthill: A Novel. I hear the science of ants (Wilson is being described as a sort of Homer of Antdom) is itself treated as a kind of character in the book. (Haven’t looked at it myself yet, though.)
Re 503 Completely Fed Up –
You’re criticizing Motl’s reasoning, which is all well and good
(though it would be simpler to point out that if the greenhouse effect were removed but the mass of the atmosphere and albedo were preserved, the pressure wouldn’t change much (in the approximation of constant graviational acceleration over height and independent of atmospheric mass below, it wouldn’t change at all), but the cooling of the surface would change the lapse rate and the end result would be a cold surface underneath a mostly stratospheric/thermospheric atmosphere, with the lapse rate being essentially nowhere maintained at or near adiabatic.)
(I suggest using that tact … because , do we even know what sort of mathematical proportionality to pressure that Motl is suggesting? – trying to disprove Motl on the basis of counterexamples to correlation of pressure and temperature seems unnecessary and somewhat beside the more important point of what atmospheric mass and pressure actually do).
(Which, to reitterate, is: 1. yes, for the given (pressure, temperature, composition, large-horizontal scale circulation, etc, dependent) tropospheric lapse rate, you need a larger weight (per unit area) of air within the troposphere to get a larger temperature difference between the surface and the tropospheric average or tropopause level, and that weight can’t be more than the weight of the whole atmosphere, BUT 2. the fraction of the weight of the atmosphere that is within the troposphere is not a fixed value, but very much depends on other things, in particular, the greenhouse effect, without which, the surface temperature will change until it is only that temperature that allows the radiant flux emitted by the surface to equal the solar flux absorbed by the surface and atmopshere.)
…
522: oops. I meant to say how the TEMPERATURE in a pure CO2 atmosphere would vary with the amount of CO2.
Kevin Stanley@521,
To be fair, FCH didn’t bring up the canard of an appeal to authority. That was Steckis, whose motivation was to make his opinion as an ignoramus equally valid with that of a scientist who has studied a subject for half a century.
In an argument based on formal logic, all appeals to authority are fallacies, because formal logic only admits statements that are true or false. Science is not entirely governed by the rules of formal logic. As Kurt Godel showed, neither is math. In fact the only place formal logic seems to apply is, well, formal logic.
I’m still waiting for a proof that the word “fish” is not spelled g-h-0-t-i.
# 453, To say Newton’s laws fell apart is misleading. They work on systems of substantial size and bodes within acceptable speeds just fine. As you noted we would not use general relativity to buld a bridge nor, I might add we would not use quantum mechanics to determine a race cars velocity. Each branch of physics works just fine for what they are intended. It is true that without GR we would not have GPS and without quantum physics we would not have CD’s and DVD’s to be sure, but Newtonian physics is still great for issues in the macro world not approaching the speed of light. Thank you for your post, just the same.
re: the MWP
It sounds like Ray Ladbury and others are denying that there had been variations in global tempartures coinciding with the so-called MWP and LIA. But look at the Law Dome CO2 concentrations for instance. How do you explain atmospheric CO2 falling from the early 12th to the early 17th century?
Do we have good pre-12th century CO2 proxies with a fairly high resolution by the way?
# 466 Ike Solem, while I will certainly not argue with you over the far reaching influence of BP and other companies within that industry I want to make two brief points:
1.) BP has a lot of explaining to do with this recent oil spill.
2.) Having been to UC Berkely recently and reading many publications form there, they are still doing a fine job in research into cleaner alternative energy sources and technology. Berekley is still quite a green center here in California.
barton, phillip, CFU, thanks to you guys too.
My good friend who will not post here because he gets such rough treatment has sent me these comments:
“Arctic ice in April was above the long term norm. Antarctica is not melting. Kilimanjaro’s glaciers are not melting due to warming because it is, as in the past, below freezing up there. Those glaciers are melting due to a drought and sublimation, not warming. Polar bear numbers are increasing. CO2 is going up but the temperature isn’t going up much even with all the numerical manipulations to increase the apparent heating which climatologists engage in.”
Is there any scientist here who will (politely) refute him? If there is, I will try to get those refutations to him.
I am not interested, nor will I forward, angry or sarcastic remarks. There are already too many of these on the posts here.
(Re 503 Completely Fed Up, continued)…
(But Motl is not completely incorrect about every fact, and in particular, the partial pressure of CO2 at the surface on Venus is much more than 2^6 times that on Earth. It is actually about 2^18 (for an approximate preindustrial CO2 concentration of 300 ppm and approximate surface pressure of 1 bar, and approximating the Venusian atmosphere as being 100 % CO2, with a pressure of 90 bar, I find a ratio of 2^18.19). But accounting for the difference between partial pressure (of a well-mixed constituent) and weight contribution (partial pressure of CO2 as a fraction of atmospheric pressure * molar mass of CO2 / average molar mass of atmosphere = mass fraction of CO2 in the atmosphere), I find that Venus has approximately 2^17.6 times the weight of CO2 per unit area as the Earth (a little higher than my prior rougher estimate) (using a molar mass of 44 g/mol for CO2 and 29 g/mol for Earth’s atmosphere); this must be divided by (Venus surface gravitational acceleration / Earth surface gravitational acceleration) to find the ratio between the two planets for the mass of CO2 per unit area, which is, absent differences in line broadenning and line strength, proportional to the optical thickness contribution at any given frequency.)
(I have no intention of reading Motl; I would imagine his argument is something to the effect of 18 doublings of CO2 * 3 K/doubling = 54 K, added to 33 K gives 87 K, which is only a fraction of the difference between the surface temperature Venus would have without a greenhouse effect (I think an inline comment stated this was 240 K) and the actual surface temperature. Or maybe Motl got more sophisticated and subtracted the effect of water vapor, etc… Of course Motl’s reasoning is deeply flawed, but the partial pressure he used is apparently not far off.)
Beer-Lambert calculations are oversimplifications for calculating radiative energy transfer through the atmosphere. Let’s build a spectrofluorometer to investigate how the atmosphere behaves. We’ll start with a 1kmX1km broadband (“greybody”) light source whose temperature can be controlled from 0 – 6000 degrees K, thermally isolated from our cuvette with a perfectly transparent window. It only emits parallel beams. It also has a zero emissivity tunable narrowband filter so we can select monochromatic illumination at any wavelength. We then place a cuvette whose optical path length is 100km, oriented vertically, and we fill it with 80%N2 &20%O2 to a pressure of 1 atmosphere and T of 15 deg C at the bottom. We turn on our light source, and measure the transmission(energy versus wavelength) through the cuvette, and fluorescence/scattering/thermoluminescence(energy versus wavelength) at right angles to the beam. Except for a teeny bit that can be explained by some dust, dark aerosols, and other crud contaminating our system at low levels, all the radiation from 0.3 to >10 micron is transmitted. We add 380ppmv CO2 to the cuvette, and repeat the measurements, and find that the transmitted light spectrum is no longer smooth, but has dips in the IR where CO2 is known to absorb, the dips don’t go to zero. We also see radiation at right angles at these same wavelengths where the CO2 is emitting. The intensity varies along the length of the cuvette, decreasing as the temperature and density decrease along the length of the cuvette. We turn off the light source, and still measure IR radiating to the side; what were dips are now peaks radiating out the top. We heat the gas mix at the bottom of the cuvette to 20 deg C. The side and top radiation increases in intensity, again at the CO2 wavelengths and with a temperature + density dependence. We turn on our light source with the filter adjusted to provide monochromatic illumination at the shortest wavelength where the CO2 is absorbing. We measure more side radiation at this wavelength, but also at longer wavelengths. We stick a thermocouple in to measure the temperature versus distance along the cuvette, and find that the temperature decreases about 6.5 degree C per kilometer(lapse rate), and changes depending on how much radiant energy is being put in by the light source, and how strongly it is being absorbed. If we put a lot of energy in at the bottom. the differential heating causes convection currents which redistribute the heat vertically.The temperature distributions and thermal radiation distribution vertically are dependent on the amount of radiation we put into the system. We start adding water vapor at the bottom of the cuvette, and we see new absorption lines appear, some overlapping the CO2 absorption lines. we also see new IR radiation lines out the side, but they fall off more quickly with height along the cuvette. As we pump in more water vapor, we soon start to see droplets, clouds, form when the local water vapor pressure reaches the dew point. Because of the lapse rate, the partial pressure of water vapor at the threshold of condensation falls by more than three orders of magnitude in the first 15 km of our cuvette. This gradient in the density of water vapor limits the side radiation of IR at water frequencies to the low levels of our cuvette. The water vapor is absorbing and reradiating at low levels and higher temperatures than the CO2 whose partial pressure is uniform. If we add enough water to create clouds, we also measure scattering out the sides of our cuvette at wavelengths that aren’t absorbed. Sunlight coming into the sides of the cuvette also now gets scattered into our detectors, so we run down to WalMart and get a really big can of Krylon 100% reflective spray paint, and spray the inside walls of our cuvette. We also get a really big can of Great Stuff foam perfect insulation and squirt it on the outside of our cuvette. Now all the scattered radiation eventually goes out the top or back into our light source, and heat doesn’t get conducted from the surrounding atmosphere. We alternately shine monochromatic light at a wavelength which is weakly absorbed by CO2 into the cuvette, and a wavelength which is not absorbed by CO2, water vapor, or clouds, and raise the water vapor content until we get cloud formation. As the clouds form, the apparent concentration of CO2 as measured by the ratio of intensity at the absorbed wavelength to the intensity at the transmitted wavelength appears to increase. WTF? We realize that the effective path length is no longer 100 km vertically through a gradient of CO2 absolute density, but is increasing as the photons scatter off the clouds, reflect from the walls, and scatter again until they eventually reach the top or bottom. Consider a photon which travels 1km vertically from our light source, scatters once at 45 degrees, and bounces back and forth at 45 degrees between the perfectly reflecting walls until reaching the detector at the top of the cuvette; the path length is now 99*sqrt2+ 1 km, or about 40 percent longer. Things get very complicated as we change the water vapor, temperature, cloud level/amb- ient lapse rate, and CO2 concentration, especially because the GHGs not only absorb but radiate. The Beer–Lambert law assumes that the absorbed photon energy does not change any of the properties or get re-emitted by the absorbing substance, and (usually) assumes a fixed, uniform path length. See http://ase.tufts.edu/biomedical/research/fantini/publications/nirs_theory/3_phys_med_biol_49_n255_2004.pdf
I wonder which grows faster with thin low clouds, albedo or effective GHG absorber path length? Does Lindzen’s purported negative cloud iris have a negative path length feedback which (double negative) cancels its effect? Gavin?
Re myself Re 503 CFU (PS It would be funny if you switched your name from Completely Fed Up to Completely Fed L__(?), then you’d be CFL. Actually, it would be even better if you were LED, but anyway…)
…”BUT 2. the fraction of the weight of the atmosphere that is within the troposphere is not a fixed value,”
And for that matter, the temperature near the tropopause is not a fixed value independent of optical properties. Etc. (Though I’m a bit uncertain, I think the lapse rate on Venus, passing the tropopause, continues to be significantly greater than zero into the lower stratosphere. And the tropopause is relatively deeper into the atmosphere (greater mass of air above it) then on Earth. So the Venusian stratosphere’s greenhouse effect could tend to keep the tropopause level warmer than it would otherwise be. On Earth, the tropopause is colder than the equilibrium surface temperature for a zero greenhouse effect case, but this needn’t always be the case; in particular, if most of the LW radiation leaving a planet is emitted from above the tropopause, then the tropopause can be warmer than the effective emitting temperature…)
“So the Venusian stratosphere’s greenhouse effect could tend to keep the tropopause level warmer than it would otherwise be.”… I meant relative to an Earthlike atmosphere with the same solar heating.
Re John E. Pearson
first, some examples of adiabatic lapse rates in liquid and solid:
“The Dynamic Structure of the Deep Earth” by Shun-ichiro Karato
p.31
the adiabatic lapse rates of:
Earth’s outer core: 0.6 to 0.8 K/km
Earth’s mantle: 0.3 to 0.4 K/km
(correcting an earlier statement from memory about the mantle’s adiabatic lapse rate; apparently I was remembering the outer core’s value.)
The lapse rate will become superadiabatic (larger than adiabatic) where convection is impeded and a large enough upward heat flow still occurs. Convection on smaller scales is slowed more easily by viscosity. Because the mantle and core are not actually mixing together, a superadiabatic lapse rate could be expected in the base of the mantle. The crust also has a superadiabatic lapse rate. A relatively thin layer of air next to the surface can sometimes have a superadiabatic lapse rate (strong solar heating of a land surface, cold air blowing over warm water) because conduction has to transfer sensible heat from the surface to the air before the air can move it around, and also, motions near the surface are somewhat impeded by the surface, but this involve a rather small portion of the atmosphere.
471
John E. Pearson says:
11 May 2010 at 11:58 AM
“Do the blogoscientists argue that the temperature a kilometer deep in Earth’s oceans (where the pressure is 90 bar) is 476 C? Or do they invoke some other new physics to explain why not? Just wondering.”
John. That is a silly argument. Oceans do not act like atmospheres as they have an incompressible medium (saline water) as opposed to atmospheres which have compressible gasses that can produce work and therefore heat when compresssed and uncompressed.
It is interesting to note that the oceans have a heat carrying capacity over 1000 times that of the atmosphere. So. Perhaps in part, we do have a venusian atmosphere because of the heat carrying capacity of the oceans.
Correction: should read “we do NOT have a venusian atmosphere”.
Martin A. Nuclear testing has had a massive effect on C isotope techniques and is heavily studied. For some applications its a disaster, rendering post-50s data unusable. For others, it creates a massive, accurate known marker for carbon studies. There is a huge literature – just check google scholar.
Anyone at RC interested in looking more closely at the recent article in The Economist? Or maybe an open thread about it? http://www.economist.com/world/international/displayStory.cfm?story_id=16099521
And thanks to those of you who lent suggestions and links (#404, 381, 367) about CO2 output from point sources. While I knew mixing is fast, I didn’t know if the constant output from individual point sources like coal fired power plants might create some regional variances. And yes, I’ll start using my full name ;) I may actually end up publishing something or other in the next couple of years (paleoclimate or volcanoes? time will tell), so I guess I should get into that habit online. I never used my full name years ago over general privacy concerns, but I realize I’m getting more into things where I need to stand by my word. So here you have my semi-cumbersome Lithuanian last name.
Now wish me luck on my petrology final tomorrow ;)
> Is there any scientist here who will (politely) refute him?
John, you don’t need a scientist to help you with those. Each of them is a standard talking point. Just copy each sentence, paste it into Google, then into Google Scholar. Subtract the nonsense, look at what remains.
For extra fun also click on Google Image Search using the same query string (most of those results will be from denial sites, they’re really good putting up pictures although they get the facts wrong).
It’s a simple exercise people here do all the time. You can do it.
For the specific “Antarctic sea ice is growing” claim, congratulate your friend on his insight: http://moregrumbinescience.blogspot.com/2010/03/wuwt-trumpets-result-supporting-climate.html
522 John E. Pearson
“Too bad we can’t post figures on RC. They’re worth a thousand words.”
some nice diagrams/graphs here:
1.
http://chriscolose.wordpress.com/2010/02/18/greenhouse-effect-revisited/#comment-2236
2.
http://chriscolose.wordpress.com/2010/03/02/global-warming-mapsgraphs-2/
3.
http://chriscolose.files.wordpress.com/2010/05/absorption_co.jpg (from http://chriscolose.wordpress.com/2010/05/12/goddards-world/#comment-2277,
“From R.T. Pierrehumbert, Principles of Planetary Climate, in publishing progress”)
4.
http://www.atm.ox.ac.uk/group/mipas/atlas/index.html
(The last two show the absorption spectrum of CO2 for wavelengths longer than 4 um. There are some rather strong bands between 4 and 5 um; these aren’t as important as the 15 micron band because of the amount of radiative flux found at those wavelengths for typical surface and atmospheric temperatures – for the Earth at least. The third website has an inset showing an example of the finer-scale texture of the absorption spectrum.)
——-
“And is the motivation for all this to explain to me how a pure CO2 atmosphere would vary with the amount of CO2?”
Not directly, but it would be part of the foundation for that. I’ve decided to try to summarize all the important things (I have a tendency to want to do that); you can use what you want. I’ll probably summarize the summary at some point so you could wait for that and trace back to these longer comments for more info if you want to try that (but go ahead and look at what others who cut to the chase are saying, of course).
PS
see also http://chriscolose.wordpress.com/2010/05/12/goddards-world/ for Venus topic.
—-
“IF Opt = optical thickness” …
“you’ve got log(Opt) ~ log(X) so I would say that Opt ~ X , no?”
YES, following the changes in Opt at any one frequency.
“Then the trick is to explain how to get an optical thickness that rolls over into log(X) because of the properties of the absorption spectrum of CO2? ”
Not really; it is the radiative forcing for the whole spectrum that is proportional to log(X). See below…
———
“I’ve read a little bit of this random band model that rolls over into sqrt(X) for larger X. But I don’t know how all this ties together.”
I don’t know about that – haven’t gotten that far.
“I’m also unclear as to how to go to optical thickness that you see in elementary expositions: T_{surface}^4 = (1+Opt) T_{e}^4 ,”
That’s an interesting equation; I’ve never seen that before; it might apply to some cases but I’m not sure if it’s a good equation to use or not.
…” which contains no information on frequency. I guess the idea is that the optical thickness in that equation is the optical thickness for the relevant wavelengths and you more or less ignore wavelengths that aren’t getting absorbed?”
It is possible to define an effective optical thickness such that, for some range of frequencies and directions, transmission = exp(-effective optical thickness). Such an “Opteff”, as I’ll call it, doesn’t generally add linearly like the actual optical thickness at one frequency and along one direction.
cont. from 499
https://www.realclimate.org/index.php/archives/2010/05/solar/comment-page-10/#comment-174438
and also 445
https://www.realclimate.org/index.php/archives/2010/05/solar/comment-page-9/#comment-174358
note clarification at 495
https://www.realclimate.org/index.php/archives/2010/05/solar/comment-page-10/#comment-174432
——-
PART III.
Considering some examples of what happens when atmospheric optical thickness at a particular LW frequency is increased from zero: (case 1 is most like the Earth and planetary atmospheres in general, so far as I know of)
1. blackbody surface (or underlying lower layer of air), atmospheric LW optical thickness from absorption:
1a. Of the flux that reaches space:
at first, it is all from the surface and has the brightness temperature equal to the surface temperature. Adding a little optical thickness lifts some of the emission weighting function off of the surface and into the atmosphere; if the optical thickness is small, then any part of the atmosphere doesn’t absorb much of what the other part emits, so the emission weighting function that is in the atmosphere is distributed as optical thickness is distributed. If the atmosphere’s average temperature (weighted by optical thickness) is colder than surface temperature, then the total flux to space decreases.
As more optical thickness is added, then, as more of the emission weighting function is lifted off the surface and into the atmosphere, the portion that is in the atmosphere becomes concentrated at higher levels (measuring the vertical distance through the atmosphere by optical thickness, as opposed to pressure or actual geometric height), and the flux that reaches space is more dependent on the temperature at higher levels in the air than at lower levels. Even if the emission weighting function is entirely lifted off the surface, the redistribution within the atmosphere can continue to change the flux that reaches space. If the temperature declines with height, then the flux continues to drop. If there is a layer of the upper atmosphere where temperature increases with height, then as the emission weighting function becomes more concentrated towards and then into that layer, the flux may level out and then start to increase.
1b. Of the net flux at some point within the atmosphere:
The upward flux is affected in the same way as the flux to space is affected, but without the effect of the optical thickness of the overlying layer. The emission weighting function is lifted off the surface, intially evenly distributed (over optical thickness) within the atmosphere, and then starts to become concentrated closer and closer to level at which the flux is evaluated, so that the upward flux eventually approaches the blackbody value for the temperature at that level.
For the downward flux, the emission weighting function is initially in space (which can be, for these purposes, treated as a blackbody near 0 K, thus the downward flux is nearly zero). Increasing the optical thickness pulls some of that weighting function into the air above the level considered, at first evenly distributed over optical thickness, and then becoming more and more concentrated near the level considered. Assuming the temperature is above zero K in the upper layer, the flux initially increases from zero. If the temperature is isothermal or decreasing with height above that point, the downward flux increases until it approaches the blackbody value for the temperature at that level. If the temperature increases with height, then the flux may overshoot that final value and then come back down; however, if the warmer parts of the layer are too thin, they might not achieve that effect – as the portion of the emission weighting function that is within the atmosphere is redistributed into lower, colder parts, if the portion of the emission weighting function that is still in space and being pulled into the atmosphere is still large enough, that effect can match or overpower the effect of the conncentration of the weighting function into colder parts, so that the downward flux holds steady or continues to increase.
Eventually, the weighting functions for both upward and downward fluxes become concentrated toward the same place, and so the two fluxes approach being equal (approaching the blackbody value for the temperature at that location) and the net flux goes toward zero. At that point, the effect at that level could be said to be saturated, as there isn’t any further change to the net flux from increasing optical thickness.
[you can skip over the rest of this if you want to save time]
1c. Doward radiation to the surface: Similar pattern of behavior as the downward radiation at any point within the atmosphere, except that the lower portion of that atmosphere contributes the effects of it’s optical thickness and temperature distribution (and will eventually hold most of the weighting function, blocking the effects of the upper layer). As the emission weighting function becomes concentrated near the surface, the net flux goes toward zero. If there is a low-level inversion (as happens at times and places in some planets’ tropospheres), the downward flux could actually increase to become larger than the upward flux from the surface before shrinking back to being nearly the same as the upward flux from the surface. Eventually, both upward and downward fluxes approach blackbody values for the temperature at the surface.
[you can skip over the rest of this if you want to save time]
2. same as 1, but with a portion of atmospheric optical thickness coming from scattering.
2a. upward radiation to space: similar to 1a, except that a fraction of the emission weighting function that is removed from the surface is transfered to space, farther reducing the flux to space; as optical thickness increases, this continues to be the case if scattering is significant up through the top of the atmosphere.
2b. net radiation at some level within the atmosphere: similar to 1b, except, as in 2a, that portions of the weighting functions are actually distibuted to the other side of the level, so that a flux in one direction partly depends on temperature in the direction the flux is going. As optical thickness increases, this continues to be the case if the scattering occurs in the region of the level. Also, at optical thickness increases, the fluxes in both directions approach the blackbody value for the temperature at that location, even though the emissivity in any direction never reaches one (if the scattering occurs at that location), because the scattering reduces the absorption of photons so that the photons build up until they are at an equilibrium density for that temperature.
2c. surface: similar to 1c, except that a portion of the downward radiation to the surface is actually emitted from the surface; as optical thickness increases, this continues to be the case if scattering occurs near the surface. Both upward and downward fluxes approach blackbody values (see end of 2b).
3. surface has some nonzero LW albedo; atmospheric optical thickness as in 1 or 2.
3a. radiation to space: If the surface LW albedo is large enough and the atmosphere is warm enough relative to the surface, and absorption has a strong enough role in atmospheric optical thickness, the flux to space will initially increase as optical thickness increases from zero (initially, some portion of the weighting function is reflected from the surface into space; some of that gets pulled into the atmopshere – both by emission upward from the atmosphere and by reflection from the surface of downward radiation from the atmosphere, a large portion of which initially is able to reach space). However, as optical thickness continues to increase, eventually the flux to space starts to decrease, if the temperature decreases with height up through enough of the weighting function, or if the scattering is concentrated toward the top of the atmosphere.
3b. net radiation at some level within the atmosphere: upward radiation Similar to 3a. Net radiation still tends toward zero as optical thickness gets large enough. Eventually, upward and downward fluxes approach blackbody values (see 2b).
3c. radiation at the surface: similar to 2c, except that the upward flux at the surface increases as the downward radiation increases, because of some reflection of the downward radiation. Eventually, as optical thickness is increased, the net flux goes toward zero. Upward and downward fluxes still approach blackbody values (see 2c, 2b).
4. atmospheric optical thickness is entirely from scattering
4a. radiation to space: The flux decreases from it’s initial value, eventually approaching zero. So long as the type of scattering is not changed (forward-dominated scattering has less of an effect than Raleigh scattering, for the same optical thickness), the flux decreases over the whole range of optical thickness values. Even if the surface has some LW-albedo, the flux still decreases, even initially. The temperature of the atmosphere has no direct effect. The weighting function, or some portion thereof, is at the surface; the rest is in space; the weightin function is lifted off the surface and transfered to space.
4b. at some level within the atmosphere: net radiation decreases toward zero.
(?) Eventually, all fluxes go toward zero (? or do they?). The temperature at that location has no direct effect.
4c. at the surface: downward radiation increases from zero, approaching the upward radiation from the surface; if the surface has some nonzero LW-albedo, the upward flux also increases due to reflection of downward radiation. The net radiation decreases and approaches zero. Upward and downward fluxes approach blackbody values (see 3c, 2c, 2b).
———
John (Burgy) Burgeson says:
12 May 2010 at 4:25 PM
My good friend who will not post here because he gets such rough treatment has sent me these comments:
“Arctic ice in April was above the long term norm…
Is there any scientist here who will (politely) refute him?
Sure: http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
But, I’m not a scientist. The cure for your poor friend is to stop listening to BS and start learning a little science. Given everything he said in the quote you gave takes little brain power to refute, we must conclude your friend has no interest in science or reality, so…
…the temperature isn’t going up much even with all the numerical manipulations to increase the apparent heating which climatologists engage in…
tell him that he can’t have it both ways: he can’t call climate scientists liars, as above, but reserve polite treatment for himself. This not only makes him either gullible, blinded by ideology (Oreskes, et al.) or scientifically illiterate, it also makes him a hypocrite.
Cheers
“we do NOT have a venusian atmosphere”.
We know.
“So. Perhaps in part, we do -not’ have a venusian atmosphere because of the heat carrying capacity of the oceans.”
Weaselling again.
In a microscopic part, perhaps.
But perhaps in NO WAY AT ALL.
And most likely of all, IN NO SIGNIFICANT WAY.
Funny how you only put forward one of three matters (and the least likely one at that) as a position, and the one that was picked leads to “CO2 doesn’t cause AGW”.
Keeping “on message”, kid? Don’t want to confuse people by giving ANY SORT of hint that maybe AGW is a problem.
Maybe the big reason why we don’t have a venusian atmosphere is because we don’t have so much CO2.
Oh, look:
Earth: 400ppm
Venus: 955000ppm
Yup. That’s proof all right: we don’t have so much CO2 therefore we don’t have a venusian atmosphere.
“But Motl is not completely incorrect about every fact, and in particular, the partial pressure of CO2 at the surface on Venus is much more than 2^6 times that on Earth. It is actually about 2^18”
Please, Patrick, don’t correct me on things I never said.
Or, if I did say them, please point to where I said that Motl was incorrect in the relative proportions of CO2 pressure.
Never did I say that.
So, with that out the way, explain this:
Why are the other gasses not producing any surface pressure?
What? They *are*???
Then, why are you and Motl taking out only the pressure from CO2 and relating that to the temperature of the surface?
“529
Anonymous Coward says:
12 May 2010 at 3:50 PM
re: the MWP
It sounds like Ray Ladbury and others are denying that there had been variations in global tempartures coinciding with the so-called MWP and LIA”
[edit]
There have been variations in global temperatures.
They weren’t higher than the recent warming.
But go ahead and make up whatever makes you happy.
“Do we have good pre-12th century CO2 proxies with a fairly high resolution by the way?”
If we don’t, how can you say that the MWP was warmer than it is today, given we have now a high resolution measurement of CO2 not via proxy but direct measurement?
But if all you want is denial of a problem, I guess there’s no need for logical consistency.
Shirley J Pulawski @ 541:
That article makes a common error, when it comes to “political causes”, in that it claims the “pro-warming” side is exaggerating claims in order to advance the cause.
A better, and more accurate, statement is that the more extreme scenarios are focused on because of risk-management. Assume that probabilities can be assigned to each outcome, and that each of those outcomes has some cost. Adding up all of the products of “probability times cost of outcome” gives a statistical cost. THAT is the issue — some super catastrophic outcome may have a low probability, but an extremely high cost associated with the outcome.
What people who are opposed to that approach miss is that by acting earlier, performing the needed changes is typically easier for the less extreme outcomes, and less likely to fail for the more extreme ones.
#532 John (Burgy) Burgeson
You have been around RC long enough that you should be able to answer these questions, however:
“Arctic ice in April was above the long term norm.”
Nope
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
In fact, who knows? But it might go below the 2007 minimum this year???
“Antarctica is not melting.”
http://www.ossfoundation.us/projects/environment/global-warming/myths/images/glacier-retreat/486913185_a721a8c3bf_o.jpg/view
This needs more context though. There are signs of some melting and increased calving rates, but according to models, ice extent was supposed to increase as the planet warmed, and that is indeed the case. But then ice extent and calving rates are two different things, which is also different from the warming signal detected in Antarctica, as well as the accumulation rates in different regions of Antarctica. Don’t forget, it’s still pretty cold down there. Think of it this way, The ice in my freezer is not melting, but the ice I put in my refrigerator is. Antarctica is not the planet, it is however the larges chunk of ice on the planet and is not going to disappear anytime soon. Think of Antarctica as the freezer and the Arctic as the refrigerator.
“Kilimanjaro’s glaciers are not melting due to warming because it is, as in the past, below freezing up there. Those glaciers are melting due to a drought and sublimation, not warming. ”
http://www.ossfoundation.us/projects/environment/global-warming/myths/images/glacier-retreat/kilimanjaro_etm_93_00.jpg/view
I’d bet there are multiple factors involved but I don’t think you can rule out warming as one of the factors. Sublimation, warming, drought??? I wonder what is causing the drought? Maybe latitudinal shift due to global warming?
“Polar bear numbers are increasing.”
Thanks to preservation efforts to prevent the wholesale slaughter of the polar bears.
“CO2 is going up but the temperature isn’t going up much even with all the numerical manipulations to increase the apparent heating which climatologists engage in.”
This sentence is simply riddled with unfounded assumptions. Context is Key: the warming since pre-industrial in around 0.8C. All you have to do is think about how much actual energy it takes to heat say your house 0.8C, then extrapolate how much energy it takes to heat the surface of an entire planet, such as earth 0.8C (Lots of energy!!!).
The paragraph just seems to be a collection of myths that someone sadly has chosen to repeat.
—
A Climate Minute The Greenhouse Effect – History of Climate Science – Arctic Ice Melt
‘Fee & Dividend’ Our best chance for a better future – climatelobby.com
Learn the Issue & Sign the Petition
Hank Roberts: Many thanks – spot on for what I was wanting on the dynamics of atmospheric CO2 concentration. It seems to be more of an open ongoing research topic than I had imagined.
Phil Scadden: Many thanks. Yes – truly a massive marker. I noticed that Sakharov’s figures on the biological effects of radioactive carbon resulting from nuclear tests lead to an estimate that the 1961 Soviet 60Mton test will ultimately have injured or killed about half a million people.