Bob (Sphaerica), the best treatment of blackbody radiation I know of is in Landau and Lifshitz’ Stat Mech text. And diatomic molecules radiate in the IR only when they are excited in collision–something that happens less and less at higher altitude. People need to remember that blackbody radiation is not some completely other kind of radiation not subject to the rules of quantum mechanics. It is merely thermal equilibrium between the photon gas and its material surroundings. An atom/molecule can still only absorb/radiate between its energy states.
[Response: Ray, what do you think of the way L&L handle Kirchhoff’s law? I’m still hunting around for a good place to send people who want a deeper understanding of the microscopic origins of Kirchhoff’s law. –raypierre]
I am glad to see her becoming more blunt in dismissing folly. Not yet as clearly as Spencer does, but better. Both attract many comments by people who are having great difficulty separating the physics from the conclusions they are determined to reach.
Lines from Blake:
\If others had not been foolish, we should be so.
…
If the fool would persist in his folly he would become wise
Folly is the cloke of knavery.\
Rod Bsays
Bob (Sphaerica), just for the record and FYI, I do not fully agree on Ray Ladbury’s characterization of blackbody/planck-function radiation versus radiation related to vibrational and rotational molecular energy changes.
[Response: I’d be interested to hear your point of disagreement. Admittedly, blackbody radiation has a lot of subtleties that aren’t evident at first glance. For a true blackbody (one that is strongly interacting with photons of all wavelengths) it really is a completely straightforward exercise in equilibrium thermodynamics, once one has the Planck quantization hypothesis. The subtlety is that we can actually make some use of equilibrium thermodynamics even if the photons are interacting strongly with matter only in a limited band of wavelengths. That little gift from nature descends from the linearity of Maxwell’s equations, or in quantum terms the fact that photons interact with matter but not with each other (at least not in the energy density regime common to planetary atmospheres). –raypierre]
Rod Bsays
Hank, I’m mostly just observing and absorbing here, but I did not get the point you were making in #142. If not too cumbersome would you explain it?
Ray Ladburysays
R. Gates: ” I would maintain, that this blog, Dr. Curry’s blog, and even such blogs as WUWT can help to supply a bit of the background necessary to “read between the lines” in differences of opinion.”
You’re kind of new at this, aren’t you? First and foremost, in science the truth is not in the middle, but rather where the evidence guides us. WUWT is an evidence-free zone and hence irrelevant to any scientific debate–except for the very useful purpose it serves as an asylum for morons.
And in disputes between scientists, it is not a matter of one scientist, one vote. You have to take into account the publication records of the scientists involved, how influential their publications have been, whether they have their own agendas, and on and on. There are good reasons for all of this. Not all scientists are equally skilled, wise or straightforward. And in some cases, a scientists’ prejudices will keep him or her from acheiving greater understanding of the subject matter. This will show up as a dearth of publications or a lack of cites if the rest of the community do not find their work helpful. The communities in which a scientist works keep up with all of this because they have to if they want to remain current in the field. As such, the proportion of scientists who agree with a proposition about the field can be a guide to the current consensus, but it need not coincide with it. You can also look whether the consensus is increasing or stable or whether it is decreasing. In the case of climate science you can also look at whether those in related fields tend to support or dissent from the consensus, but this is not always a reliable guide.
In the case of climate science, the only way you can deny that it is happening or that we are causing it is self delusion. One can legitimately state that there remains uncertainty in how severe the consequences may be–but in doing so, one must acknowledge that there’s more probability on the high side of severity than on the low side. Uncertainty is NOT your friend if you favor inaction.
Lawmakers have access not just to studies by the IPCC, but also the National Academies, Professional Societies of scientists and Federally funded Research scientists. Why, pray would they turn to blogs unless they don’t like the answers they are getting from the professionals?
Ray Ladburysays
Rod B.@152, True, but then, you don’t understand it.
Sloopsays
@140 Dr. Curry,
Dr. Pierrehumbert’s critique in #87 of your knowledge of the physics radiative transfer is certainly harsh. Specifically, his following statement:
“Nonetheless, the term [back radiation] has been used for quite a while without creating any confusion, at least among people who understand the rudiments of radiative transfer. . . [U]ntil Judy Curry got involved with the term on her blog, it never occurred to me that somebody could get themselves so confused and tied into knots over such a simple unambiguous concept. The confusion over there has nothing to do with the term itself, but a lot to do with Judy’s not having any conception about how little she knows about radiative transfer subjects that were well worked out nearly a hundred years ago.”
Since he is referring to posts and commentary from your blog Climate, etc., presumably he could cite writings by you that back up his criticism. And if I were him, I’d be sure about being able to do so before so criticizing you publicly. I’ll leave it to Dr. Pierrehumbert to show that he can walk the walk as well as talk the talk. And it is understandable that you take great exception to his view of your knowledge in this area.
However, your response in #140 leaves a lot to be desired. Putting aside the dripping sarcasm of your opening paragraph, (revealing in itself, possibly inadvertently) a long list of peer-reviewed publications is hardly a compelling retort. It exemplifies a common debating error. Namely: “my position is correct in this specific issue because I have a graduate degree in a relevant field and have worked professionally in a relevant field for X years.” That may be reason to listen closely to somebody’s view, but it says nothing of relevance regarding the quality or credibly of that view. It’s “believe me because I know what I’m talking about”, which ultimately is circular, and a distressingly common phenomena in technical, science, and policy debate.
A better response to Dr. Pierrehumbert would have been something like this:
Ray: your comments in #87 regarding my discussions of radiative transfer physics are quite harsh. I take exception to them. Therefore could you please point out the specific passages or comments that I wrote which you find to be so erroneous or ignorant? That would enable me to explain myself better, or even to point out where you in fact are in error on this topic.
Among its positive attributes, Dr. Pierrehumbert would be obliged to be specific about what made him so discouraged about your knowledge of this are of science. And ensuing silence on his part would look bad.
Second, with regard to Adam R.’s quote of you in #144 as follows:
“Once the UNFCCC treaty was in place, there was pressure on the IPCC to back this up with science. Hence the “discernible” in the SAR. Ben Santer has taken huge heat for that, but look at where the pressure was coming from. The whole UNFCCC treaty wouldn’t make sense unless there was at least “discernible” evidence that this was actually happening.”
While Dr. Pierrehumbert’s criticism of you was serious, ultimately it’s a debate between you and him, with ramifications that don’t propagate much further beyond the reputations and professional credibility of two individuals, however hardworking, upstanding, and dedicated they may be.
On the other hand, if Adam R.’s quote of you is accurate, your criticism of international climate treaty negotiations and the IPCC has potentially serious ramifications for many many folks who must in the end trust their governments and the scientific communities to get it right on such issues and challenges.
Extraordinary accusations require extraordinary evidence. I beseech you to think deeply about the potential consequences of stating such views publicly in the blogosphere, before Congress, and in various mainstream media. If you have that evidence or can point to credible sources for such evidence, than speak forthrightly. I am prepared to hear it, consider it, and evaluate it on behalf of the government leaders I report to.
If you cannot provide or point to such evidence, than such accusations are simply irresponsible.
raypierresays
Update on the O2 continuum absorption:
Although the O2 continua don’t play any role in determining the greenhouse effect on any planet I’m aware of, there has been a fair amount of work on the continua because it is of intrinsic interest as a problem in molecular physics, and because the near-IR can have a detectable (though slight) effect on near-IR absorption of solar radiation by Earth’s atmosphere. To get the flavor of some of this work, look at:
and the references therein. I haven’t yet found a database for O2 collisional continua that is as convenient to use as the ones provided by Courtin for N2, or by Borysow for a variety of other gases. Perhaps some of the readers here can help out. There are a lot of O2 spectroscopy papers out there to comb through and some more eyeballs would be useful.
Sorry, I think I confused you. My comment in 148 was a reply to Ray Ladbury‘s comment in 136 (about my question to you in 131), not your inline reply to my question in 131.
From an analysis of world food price rises by Paul Krugman:
Most of the decline in world wheat production, and about half of the total decline in grain production, has taken place in the former Soviet Union — mainly Russia, Ukraine, and Kazakhstan. And we know what that’s about: an incredible, unprecedented heat wave.
Obligatory disclaimer: no one event can be definitively assigned to climate change, just as you can’t necessarily claim that any one of the fender-benders taking place right now in central New Jersey was caused by the sheet of black ice currently coating our roads. But it sure looks like climate change is a major culprit.
The corncrakes are complaining…
R.Gatessays
Re: Ray at #154:
You make many fine points, and certainly, as I hope as my post indicated, I’m not suggesting that the blogosphere could ever make up for any of the traditional routes that policymakers use to gather critical information and make decisions, but rather, they fill a increasingly important social roll of sizing up the landscape of differences between the experts. The comments between the experts are the most interesting and valuable, and even though one expert may have more credentials and expertise in a given area, and clearly recognized as the “leading” authority, dissenting opinions by other PhD’s do get traction in the political arena simply due to the fact that, at least in the U.S., that political arena is highly polarized. Reading blog exchanges between PhD’s on a given climate subject area helps to set at least give some of the background and see where the science may not be settled. For example, J. Curry’s attempt at creating a discussion on “Slaying the Dragon” was helpful in that a policymaker, or their staff could potentially discount this book, and know where the weaknesses are if any of their political opponents should be so foolish as the quote from it or reference it as a reason for doubt or inaction.
> 142
Saying I wish her luck over there, but I think she’s an optimist.
Heraclitussays
Does anyone else notice a certain asymmetry in these two sets of quotes?
“When I make a public statement about what a scientist does or does not know, I make a point of actually reading what that scientist has to say on the subject, rather than what other people say about that scientist on blogs.”
“Let me say that this is one of the most reprehensible attacks on a reputable scientist that I have seen, and the so-called tsunami of accusations made in regards to climategate are nothing in compared to the attack on Wegman.” and then “So I rose to Wegman’s defense, without being anywhere near adequately informed to get involved in a discussion on this.”
Since no one has yet mentioned it: two reports out today, one on Russians drilling down to Lake Vostok in Antarctica to extract multi-million years old living material; the other on the all-time historic low Arctic ice formation for January.
Patrick 027says
Re 146 – R.Gates The majority of those setting climate related policy will hardly be able to understand the complexities of radiative transfer,
Maybe, but the underlying principles are actually quite easy (in my mind, far easier than understanding much of the rest of climate physics):
Picture smoke. Okay, if it’s more familiar, picture fog. Think about how far you can see through it – how you see more of the fog and less of other things as it gets thicker, how you see more of the closer bits of fog and less of the farther bits of fog as it gets thicker.
The fog is scattering radiation; it’s temperature doesn’t matter directly in how it affects what you see (indirectly via effects on optical properties – freezing fog is a bit different, etc.), but in net effect it reflects (backscatters) some radiation toward where it comes from, blocking radiation from one place from getting farther, to greater extents as the fog gets thicker, etc.
Now go back to smoke. Let’s make a smoke that doesn’t scatter much light, so it mainly absorbs and emits radiation; the emission increases with higher temperature. Picture how it looks over different distances with different thicknesses of smoke with different temperature distributions. For a given thickness it emits more if it is hotter; over a given distance and for a given thickness it absorbs a fraction of incident radiation, that fraction is the absorptivity of that path length; over the same path it emits the same fraction (emissivity, equal to absorptivity) of blackbody intensity, the intensity of radiation that is in equilibrium with other matter at that temperature. Thus, over longer distances or with thicker smoke, or with smaller temperature gradients, the amount of radiation seen at a given location tends to correspond more closely with the temperature at that location (and tends to be closer to the same in all directions, with little-to-no net flux in any direction); thinner smoke reveals radiation coming from farther away in amounts corresponding to temperatures found farther away.
The fog blocks radiation coming toward you from behind and replaces it with radiation coming from behind you. The smoke blocks radiation by absorbing it and replaces it with what it emits.
The gases in the atmosphere generally act like the smoke, of varying thicknesses depending on amount, type, and wavelength. Clouds act more like the smoke than the fog at longer wavelengths where emission at the relevant temperatures is significant. Temperature generally decreases with height through the troposphere, above which, in the global average at least, to a first approximation, the vertical energy flux is accomplished by radiation alone.
Pete Dunkelbergsays
It was a clear and chilly night….
If I may return to that matter, I have seen comments on warming nights here and elsewhere but I still have questions. It is said and published I think that the average nighttime temperature anomaly is greater than the daytime anomaly. In addition, record low temperatures for a given place and day of the year (eg, your town and the date of 4 July) are much scarcer in recent decades than record high temperatures.
Can I say that in general, clear cool nights are not as cool as they used to be? Could this be due to water vapor alone, or is CO2 in the troposphere a cause? To what extent if any can “nights warming faster than days” support attribution? I don’t see that it can, but what does RC say?
@RGates #160, you wrote: “I’m not suggesting that the blogosphere could ever make up for any of the traditional routes that policymakers use to gather critical information and make decisions, but rather, they fill a increasingly important social roll of sizing up the landscape of differences between the experts.”
I’d be horrified if I learnt that policy makers thought, for example, that Curry’s blog, or CA, or WUWT reflected ‘the landscape of differences between the experts’. Those blogs are not dominated by experts, or except in the case of Curry, not run by anyone having scientific expertise. Even with Curry’s blog, her posts are more often pseudo-philosophic twaddle than science (or snide remarks and insinuations about her colleagues) and most of those commenting are deniers.
I would not rely on them to guage public opinion, either. They attract the same relatively small group of people.
Realclimate.org posts provide some good insights into the science and many of the comments are from informed people (and many aren’t, which is in keeping with the purpose of the site.) I’d not be as surprised or dismayed if science advisers were frequent visitors to this site (or climateprogress.org, to supplement their knowledge of technical developments etc)
On the whole, policy makers would be much better informed about the science if they used advisers who kept abreast of scientific and technical journals. And better informed about the concerns (and notions) of the public if they used market researchers who poll public opinion.
Michaelsays
Judith Curry has finally got around to defending Gavin from her hordes of winged monkeys.
But, as is her style, she also has to have a self-indulgent dig;
“And I agree that his [Gavin’s] style on the blog often comes across as arrogant and authoritarian”
R.Gatessays
To Sou@ #167-
You make some good points, but I’m not suggesting at all that policymakers or their staff would learn any substantial science behind climate change by coming to blogs, but rather, to learn a bit more about the real dynamics of who the players are, to size them up a bit, and learn how to “read between the lines” as it were, when comparing the differences of opinion between them. Certainly in the blogosphere, sites will have more or less value, and a different kind of value, than others in sizing up the players. It certainly it speak volumes about Trenberth that he refuses to engage at all here (I’m not saying this is a bad personal choice of his). But like it or not, this forum (i.e. the blogosphere) is here to stay and grow in it’s influence and importance in the ways I’ve outlined above. Nothing will take the place of simply picking up and reading credible journals to learn more about the science, but to learn a bit about the differences in perspective that the people behind that science have, the blogosphere is becoming an essential tool. Understanding those differences, and the basis for it(unsettled science vs. raw academic talent and knowledge) can be vital to settling in on sound climate policy and defending it against political opposition.
Not looking for the last word at all. Just exploring a challenging claim.
Suppose the rain in Spain fell only on the plain. All the calcium ions were leached away and never replenished from erosion from the mountains. Then, no matter how heat might accelerate formation of limestone, none would form. We currently have a situation where water evaporates from the Indian Ocean but very little rain falls down wind on the Sahara. I wonder if a model that is not one dimensional might turn up something that goes counter to your expectation of enhanced weathering?
Where I was going in the last comment was that sometimes very good scientists (Rees was elected President of the Royal Society) make ‘trust me’ statements. These statements don’t have value as scientific statements but do give prominence to the issue just because of the manner in which they are put.
Damiensays
A random question:
How is the earth’s crust modelled, and does it have any meaningful effect on how heat is distributed around the earth in any climate change scenarios? Could it, for example, have any effects at regional level, or (mis-?)modelling have an effect on thermal inertial on earth and the transient response to climate change?
Or is it simply too small to bother with when compared to heat distribution (and currents) throughout the oceans?
Scot Dannersays
Apologies if this is the wrong place to ask; perhaps some kind soul will point me in the right direction, even if it’s just the exit.
We all did the elementary experiment with the thermometer in the ice bath over the Bunsen burner: the temp stays at 0 until all the ice melts. I’m wondering if anyone has done a quantitative analysis of how much of a moderating effect all the polar ice melting is having on global temperatures.
I could just about calculate the total heat of crystallization involved, but then I’d have no idea whether that quantity was negligible or significant. Thanks for reading. Cheers.
MalcolmTsays
@ The Raven #159: No single extreme weather event can be blamed on climate change, as you say, but I agree: it sure does look like we can attribute a largish part of the blame for the recent rash of extreme events on AGW. Has anyone tried to quantify this?
Disclaimer: I have a vested interest in finding out more. Cyclone Yasi just went over the top of us.
aphillipssays
How are chaotic oscillations included in climate models? This came up in a discussion about “global warming has stopped.” My understanding is that, since natural internal variability is of greater magnitude than greenhouse forcing, it’s no surprise to see periods of relative cooling or no trend, and that these are predicted to continue over the 21st century. The enhanced greenhouse effect does not stop the oceans sloshing about. Someone told me that the models are all wrong because they can’t capture chaos. So I did a little reading (I’m a total layperson), and found things about the period doubling cascade and other routes to chaos. Can anyone point me in the right direction, or give a short explanation on modelling chaos and models acheiving ENSO etc. oscillations and interannual variability?
Hunt Janinsays
In my book-in-progress on sea level rise, I’d like to describe the 300-pp. U.S. Climate Change Science Program’s January 2009 study, “Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region”, as “one of the most recent and most comprehensive US Government reports on sea level rise.” Is this an accurate statement? If it is NOT, please let me know off-list at huntjanin@aol.com.
Ray Ladburysays
R. Gates, I believe you missed my point. Why should policy makers turn to blogs when they can ask (and have asked) the National Academies for advice, and that is precisely the reason why the Academies were founded? Some “science” blogs are a joke. Some are unreliable. Some (like Realclimate and Tamino) are absolutely stelar. Do politicians and policy makers have the experience and judgment to know which is which? On the other hand, the Nantional Academies have been a reliable source for synthesizing scientific consensus for policy makers for 150 years.
When faced with a strong consensus, I think it is a natural human tendency to look for dissenting opinions. That is not how science works. Often in science,when you have a strong consensus, the only voices it does not include are the cranks or the ideologically blinkered. The cranks are much easier to find in the blogosphere than in a NAS study. Do policy makers know the difference? If so, why are they looking to the blogosphere in the first place?
The best of the blogs can play a critical role in educating people about the science. The worst of the blogs serve no useful role other than as objects of ridicule. It is pretty clear to me that a lot of our elected officials cannot distinguish between the two classes.
Edward Greischsays
154 Ray Ladbury: People who “read between the lines” are jokers and provokers, not scientists. “Reading between the lines” is just a means of provoking anger by refusing to hear that which is written on the lines. You can’t read where nothing is written. Provokers are people who are afraid to express their own anger, so they go about getting other people to express anger for them. Provokers are and have a psychological problem. Just avoid them and refuse to communicate with them, for your own good.
“And in disputes between scientists, it is not a matter of one scientist, one vote.” That much is true.
“You have to take into account the publication records of the scientists involved”
False. Scientists do not have a proportional vote because no human has a vote. Only Mother Nature has a vote. There is no democracy. Nature is the absolute dictator. Science has nothing to do with popularity.
Do not do a Thomas Kuhn [The Structure of Scientific Revolutions] or a Ryghaug and Skjølsvold or a Jerry Ravetz. Physics is not about sociology. Physics is about rock-hard physical reality and nothing else. The “current consensus” is a guide only to those who have no hope of understanding it, whatever “it” is. Lawmakers ought to understand the science, and that is a moral “ought.” Without understanding, they cannot make adequate laws.
Ray Ladburysays
Edward Greisch,
I agree that nature ultimately gets the only vote that counts, but the problem is that she plays her cards very close to her bosom. Unfortunately, policy must be based on prognostication, not history, and scientific consensus is the best guide we have for prognostication. I’ve stated before why I think this is so–e.g. that those with the best understanding of their field with usually be the most prolific and influential publishers in that field.
And I do not think that lawmakers need necessarily understand “the science.” That may be too much to expect given that they must pass laws affected by all areas of science and technology. However, I think they have to uderstand science (e.g. method and why science works) well enough to identify and listen to the true experts in the field.
Adam R.says
A rare instance of a denier propagandist feeling consequences:
The suit (attached below) arises from an article that Ball penned for the right-wingy Canada Free Press website, which has since apologized to Weaver for its numerous inaccuracies and stripped from its publicly available pages pretty much everything that Ball has ever written.
SecularAnimistsays
MalcolmT wrote: “No single extreme weather event can be blamed on climate change …”
No weather event, extreme or otherwise, can be “blamed” on any single cause, including global warming.
All weather events arise from a multitude of causes and conditions.
And global warming is now a pervasive, inescapable condition that affects all weather events.
JCHsays
No, changes in temperature and water vapor have never been causes of weather, and you alarmists are not going to get away with changing that!
[Response: Oh golly, thanks for opening my eyes on that! And here I always thought heat waves had something to do with, well you know, the temperature sort of getting higher. –raypierre]
JCHsays
Unfortunately, policy must be based on prognostication, not history, and scientific consensus is the best guide we have for prognostication. – Ray Ladbury
With respect to the Brisbane flood this is why it is so important to them to claim the flood was not unusual when compared with past floods. The decision for new flood mitigation should exclude AGW considerations. Since the recent Brisbane flooding caused significant damage and took lives, past decisions on flood mitigation are under their microscope. The historic record led experts to propose additional dams. Australians rallied against them and they were not built. This is a political opening, and a means of implying the opponents of the dams are murderers, which has been done on blogs.
So in a way the strategy is to take the weather changes they know will happen because of AGW and using any catastrophe they cause as a means of defaming environmentalists, who chose lung fish over human beings.
A real possibility is the flood was likely caused by a weather event that was unique. The final analysis will tell the story. The flood-mitigation infrastructure failed to hold the flood level to the predicted level, which could be an indication something outside the historic record took place.
But to them the fix is simple: build the dams the historic record indicated were needed.
[Response: Hang on a second. I don’t know the particulars in Australia, but dams historically haven’t helped mitigate flooding; quite the opposite. It ain’t so simple.–eric]
R.Gatessays
If only politics were like science, and simple “consensus” were enough to move policy forward. If that were the case, there might not need to be letters like this one, written by scientists to members of Congress:
Like it not, the Blogosphere is the new global town hall, and both scientist and politician needs to move effectively through this new space…
MapleLeafsays
Re #168,
So Curry “defends” Gavin with an ad hominem attack of her own? How sweet. Not the way to build bridges.
How about a sincere and unequivocal defense Curry? No rhetoric, no innuendo– you know, just doing the right thing for the right reasons.
Rod Bsays
raypierre, re your response in #148. To clarify, I’m pretty sure you are saying that molecules with no dipole moment (like N2 and O2) will absorb virtually no IR radiation, but if one of those molecules collides with another molecule its physical configuration might be misshapen, causing a dipole, so that at the instant of collision it can indeed absorb IR radiation into its vibration or rotation energies. Did I get this correctly?
If so what is the prevalence or likelihood of such absorption, given that the average N2 or O2 molecule is colliding with something extremely frequently? Is there something akin to an Einstein coefficient that puts a (low??) probability or (high??) half-life on such collision coincident absorptions? Or does the nature of the physical collision play a part also?
Thanks.
[Response: Yes, that is how collision induced absorption (CIA) works. The quantification of the probability of absorption is given by the binary absorption coefficient tables I linked to in one of my earlier answers. See the papers on the Borysow site I linked to for details of how the quantum mechanical computation is done. –raypierre]
Rod Bsays
Bob (Sphaerica), I might suggest the term “Planck function radiation” which might unwrap the semantic differences with “blackbody radiation.” Blackbody literally, as you say, seldom exists and is an ideal rather than a fact. But planck function radiation is the exact same general process as blackbody without the nitpick baggage. [Though if the meaning is understood, “blackbody” is much easier to write and say…]
Marcosays
JCH #181:
I’m not sure I’m happy to have clicked your link…
I think this is another for curryquotes. After reading Trenberth’s essay thrice, I still can’t see how she could interpret that as saying “scientists should call the policy shots”.
R.Gatessays
Just a follow-up to post #182 –
Scientists can write all the letters they want, but the political reality, like it or not (and I don’t especially) is that money ultimately runs D.C.– not logic and science. See this illuminating article from today’s LA Times:
So, if you are of the mind-set that AGW is not just real, but likely to cause serious problems, then an equally serious and frustrating problem is the way politics works. In such a scenario, money trumps all, until nature does.
Septic Matthewsays
181, eric in comment: dams historically haven’t helped mitigate flooding; quite the opposite
In what area of the US did the TVA dams increase flooding? Did the dams of China (Three Gorges Dam et al.) cause increased flooding in China in 2010 compared to pre-dam eras?
The levees along the banks of the Mississippi protect towns and croplands from most floods, but increase the extent of the flooding in the 3% or so most extreme floods. But the upstream dams all over the region from the Appalachians to the Rockies have not heretofore (to my knowledge) been said to have been responsible for increased downstream flooding.
How about dams in California, in the San Gabriel Mtns and the Sierras? Have they increased the depth, extent, frequency or economic costs of flooding?
Septic Matthewsays
151, Hank Roberts: Look back at JC’s blog (or, shudder, if you follow it regularly, which I certainly don’t): she’s started one topic after another attempting to reach some common agreed facts — and each has gone the same way, badly.
FWIW, I agree.
aphillipssays
Apologies if this appears twice.
I have a question about modelling chaos. Someone told me that models are wrong, because they can not accurately represent the chaotic oscillations of ENSO events and inter-annual variability. This doesn’t seem to be right – I read of something called the period doubling cascade as a “route to chaos.” Is anyone able to sum up modelling chaotic oscillations, and how they are fed into climate models, in lay terms?
[Response: I can’t, but of course, any time you hear the phrase “models are wrong” immediate red flags should go up, because it indicates that the person making the claim doesn’t really understand what modeling is all about in the first place.–Jim]
Adam R.says
@151 Hank Roberts: Look back at JC’s blog (or, shudder, if you follow it regularly, which I certainly don’t): she’s started one topic after another attempting to reach some common agreed facts — and each has gone the same way, badly.
Inevitable. See the heroic efforts at Science of Doom for an illustration of the futility of a genuine skeptic’s attempts to bring deniers to the proximity of reality. They don’t want to know. Engaging with them is a guaranteed waste of time.
[Response: Hang on a second. I don’t know the particulars in Australia, but dams historically haven’t helped mitigate flooding; quite the opposite. It ain’t so simple.–eric]
Your logic is about to be put to the test in Australia, and I agree that it is very complicated. If you look at the 1983 flood level versus the 1974 flood level, there is an obvious difference. Some would argue part of it was the flood-mitigation provided by the Somerset Dam, which was finished in 1959. Obviously an accounting of the water has to be included.
After the 1974 flood a comparison was made, and they decided to build the Wivenhoe Dam. A later analysis indicated the Wivenhoe Dam needed upgrading. They completed a phase of that in 2005. In mid-January of 2011, the Wivenhoe failed to hold the flood level to the prediction: which I believe was 2 meters under the 1974 crest.
Many bloggers looked at that graph and concluded the 2011 flood was much less severe than either 1974 or 1893 (Curry and Pielke Jr.are examples,) and that claim has been made in the comments section here. I do not agree with them.
What they will argue is building the dams the public refused to build in past decades would have mitigated much of the 2011 flood in Brisbane.
If dams do not mitigate flooding, as you say, then they could have converted the flood-mitigation components of both the Somerset and Wivenhoe Dams to water storage. I think that is a tough sell. The 2011 flood would have likely topped 1974, and possibly 1893. With no mitigation capacity, all the rainwater flowing into the dams would have been sent straight to Brisbane.
“Summary
Large dams have provided extensive benefits during the past 60 years: for example, fueling the powerful economy in the Western United States through cheap power, irrigation and municipal water supplies. There has also been a dark side of these massive civil works projects that were not fully comprehended during the early project planning process. This is not surprising since ecosystem response and physical processes at the basin scale are immensely complex and could not have been fully anticipated with the state of science in the 1930s and 40s. The implementation and management of large dams is still a relatively new science, compared to the time frame necessary to detect and understand some negative impacts occurring at the watershed scale. This paper attempts to summarize the unforeseen or unanticipated environmental consequences of these projects, as well as potential ramifications to the overall performance of the project. One of the important management concerns is to ensure that there is a viable decommissioning strategy for the dam at the end of its design life, and including this cost in the life cycle cost-benefit analysis….”
Patrick 027says
Re 170 Chris Dudley – in climatic equilibrium, precipitation balances evaporation in a global time average. Imbalances will of course exist regionally and temporally. The present H escape to space is quite small; there is not much of a H2O sink at high altitudes – well, actually CH4 oxidation is a source, but again, small relative to surface fluxes of H2O (etc. for photosynthesis, respiration)…
I haven’t seen the fig 5 you wrote of, but I’m guessing, that maybe the higher RH (relative humidity) shown at 25 km is in the stratosphere and not expected to be a significant source region of precipitation reaching near the surface. Precipitation generally falls from clouds, which are generally local maxima in RH in an otherwise generally unsaturated troposphere (in fact the precipitation helps produce dry air by removing H2O – consider what happens when the air in a cloud sinks/warms, without the same total amount of H2O that was present when it formed).
Of course if in some odd scenario rain did not reach the surface but hail did, then the hail fall would be what balances evaporation (setting aside frost/dew/etc.).
dhogazasays
How about dams in California, in the San Gabriel Mtns and the Sierras? Have they increased the depth, extent, frequency or economic costs of flooding?
It will be interesting to see what Eric says, but keep in mind that not all dams are built with flood mitigation in mind. For instance, the dams along the Columbia are all (to my knowledge) traditional hydro (Bonneville, Grand Coulee, and others) or run-of-the-river dams (such as the John Day) built both for hydro and to raise the level of the river behind the dam to reduce irrigation costs for nearby farms (they don’t have to pump it as far).
So a more specific question is how well do dams built primarily for flood mitigation work? In the case of the Wivenhoe Dam we’re probably going to learn a lot over the next few years, I’m sure it’s going to be intensely studied for some time.
Edward Greischsays
178 Ray Ladbury: The scientists should write the laws. Which scientists? Mike Mann, Jim Hansen, and RealClimate. Jim Hansen should run for the US senate. The laws will not be correct until the scientists have political power. That is why we humans are in danger of going extinct. Scientists may be given power as soon as it is too late to do any good.
I know that scientists don’t want political power. It just isn’t in our job description. Nor does it fit our personality type. We don’t have the numbers of scientists required to form a voting block. etcetera.
Politicians “have to understand science (e.g. method and why science works) well enough to identify and listen to the true experts in the field.” But they don’t. They understand getting money to get re-elected. So evolution, alias gigadeath, is going to happen. If we are lucky, the average math IQ will go up a few points.
the scientists should write a proposed law and proposed implementing regulations and explain what the law and regulations would do if implemented. The economic and social differences from BAU should be included. The scientists should act as a shadow government, as some out-of-power political parties do.
dhogazasays
I should say “not with flood mitigation as a primary purpose…”
Obviously when floods threaten, river managers will do what they can with the tools they have…
Bob (Sphaerica), the best treatment of blackbody radiation I know of is in Landau and Lifshitz’ Stat Mech text. And diatomic molecules radiate in the IR only when they are excited in collision–something that happens less and less at higher altitude. People need to remember that blackbody radiation is not some completely other kind of radiation not subject to the rules of quantum mechanics. It is merely thermal equilibrium between the photon gas and its material surroundings. An atom/molecule can still only absorb/radiate between its energy states.
[Response: Ray, what do you think of the way L&L handle Kirchhoff’s law? I’m still hunting around for a good place to send people who want a deeper understanding of the microscopic origins of Kirchhoff’s law. –raypierre]
Look back at JC’s blog (or, shudder, if you follow it regularly, which I certainly don’t): she’s started one topic after another attempting to reach some common agreed facts — and each has gone the same way, badly. E.g. http://judithcurry.com/2010/11/30/physics-of-the-atmospheric-greenhouse-effect/
I am glad to see her becoming more blunt in dismissing folly. Not yet as clearly as Spencer does, but better. Both attract many comments by people who are having great difficulty separating the physics from the conclusions they are determined to reach.
Lines from Blake:
\If others had not been foolish, we should be so.
…
If the fool would persist in his folly he would become wise
Folly is the cloke of knavery.\
Bob (Sphaerica), just for the record and FYI, I do not fully agree on Ray Ladbury’s characterization of blackbody/planck-function radiation versus radiation related to vibrational and rotational molecular energy changes.
[Response: I’d be interested to hear your point of disagreement. Admittedly, blackbody radiation has a lot of subtleties that aren’t evident at first glance. For a true blackbody (one that is strongly interacting with photons of all wavelengths) it really is a completely straightforward exercise in equilibrium thermodynamics, once one has the Planck quantization hypothesis. The subtlety is that we can actually make some use of equilibrium thermodynamics even if the photons are interacting strongly with matter only in a limited band of wavelengths. That little gift from nature descends from the linearity of Maxwell’s equations, or in quantum terms the fact that photons interact with matter but not with each other (at least not in the energy density regime common to planetary atmospheres). –raypierre]
Hank, I’m mostly just observing and absorbing here, but I did not get the point you were making in #142. If not too cumbersome would you explain it?
R. Gates: ” I would maintain, that this blog, Dr. Curry’s blog, and even such blogs as WUWT can help to supply a bit of the background necessary to “read between the lines” in differences of opinion.”
You’re kind of new at this, aren’t you? First and foremost, in science the truth is not in the middle, but rather where the evidence guides us. WUWT is an evidence-free zone and hence irrelevant to any scientific debate–except for the very useful purpose it serves as an asylum for morons.
And in disputes between scientists, it is not a matter of one scientist, one vote. You have to take into account the publication records of the scientists involved, how influential their publications have been, whether they have their own agendas, and on and on. There are good reasons for all of this. Not all scientists are equally skilled, wise or straightforward. And in some cases, a scientists’ prejudices will keep him or her from acheiving greater understanding of the subject matter. This will show up as a dearth of publications or a lack of cites if the rest of the community do not find their work helpful. The communities in which a scientist works keep up with all of this because they have to if they want to remain current in the field. As such, the proportion of scientists who agree with a proposition about the field can be a guide to the current consensus, but it need not coincide with it. You can also look whether the consensus is increasing or stable or whether it is decreasing. In the case of climate science you can also look at whether those in related fields tend to support or dissent from the consensus, but this is not always a reliable guide.
In the case of climate science, the only way you can deny that it is happening or that we are causing it is self delusion. One can legitimately state that there remains uncertainty in how severe the consequences may be–but in doing so, one must acknowledge that there’s more probability on the high side of severity than on the low side. Uncertainty is NOT your friend if you favor inaction.
Lawmakers have access not just to studies by the IPCC, but also the National Academies, Professional Societies of scientists and Federally funded Research scientists. Why, pray would they turn to blogs unless they don’t like the answers they are getting from the professionals?
Rod B.@152, True, but then, you don’t understand it.
@140 Dr. Curry,
Dr. Pierrehumbert’s critique in #87 of your knowledge of the physics radiative transfer is certainly harsh. Specifically, his following statement:
“Nonetheless, the term [back radiation] has been used for quite a while without creating any confusion, at least among people who understand the rudiments of radiative transfer. . . [U]ntil Judy Curry got involved with the term on her blog, it never occurred to me that somebody could get themselves so confused and tied into knots over such a simple unambiguous concept. The confusion over there has nothing to do with the term itself, but a lot to do with Judy’s not having any conception about how little she knows about radiative transfer subjects that were well worked out nearly a hundred years ago.”
Since he is referring to posts and commentary from your blog Climate, etc., presumably he could cite writings by you that back up his criticism. And if I were him, I’d be sure about being able to do so before so criticizing you publicly. I’ll leave it to Dr. Pierrehumbert to show that he can walk the walk as well as talk the talk. And it is understandable that you take great exception to his view of your knowledge in this area.
However, your response in #140 leaves a lot to be desired. Putting aside the dripping sarcasm of your opening paragraph, (revealing in itself, possibly inadvertently) a long list of peer-reviewed publications is hardly a compelling retort. It exemplifies a common debating error. Namely: “my position is correct in this specific issue because I have a graduate degree in a relevant field and have worked professionally in a relevant field for X years.” That may be reason to listen closely to somebody’s view, but it says nothing of relevance regarding the quality or credibly of that view. It’s “believe me because I know what I’m talking about”, which ultimately is circular, and a distressingly common phenomena in technical, science, and policy debate.
A better response to Dr. Pierrehumbert would have been something like this:
Ray: your comments in #87 regarding my discussions of radiative transfer physics are quite harsh. I take exception to them. Therefore could you please point out the specific passages or comments that I wrote which you find to be so erroneous or ignorant? That would enable me to explain myself better, or even to point out where you in fact are in error on this topic.
Among its positive attributes, Dr. Pierrehumbert would be obliged to be specific about what made him so discouraged about your knowledge of this are of science. And ensuing silence on his part would look bad.
Second, with regard to Adam R.’s quote of you in #144 as follows:
“Once the UNFCCC treaty was in place, there was pressure on the IPCC to back this up with science. Hence the “discernible” in the SAR. Ben Santer has taken huge heat for that, but look at where the pressure was coming from. The whole UNFCCC treaty wouldn’t make sense unless there was at least “discernible” evidence that this was actually happening.”
While Dr. Pierrehumbert’s criticism of you was serious, ultimately it’s a debate between you and him, with ramifications that don’t propagate much further beyond the reputations and professional credibility of two individuals, however hardworking, upstanding, and dedicated they may be.
On the other hand, if Adam R.’s quote of you is accurate, your criticism of international climate treaty negotiations and the IPCC has potentially serious ramifications for many many folks who must in the end trust their governments and the scientific communities to get it right on such issues and challenges.
Extraordinary accusations require extraordinary evidence. I beseech you to think deeply about the potential consequences of stating such views publicly in the blogosphere, before Congress, and in various mainstream media. If you have that evidence or can point to credible sources for such evidence, than speak forthrightly. I am prepared to hear it, consider it, and evaluate it on behalf of the government leaders I report to.
If you cannot provide or point to such evidence, than such accusations are simply irresponsible.
Update on the O2 continuum absorption:
Although the O2 continua don’t play any role in determining the greenhouse effect on any planet I’m aware of, there has been a fair amount of work on the continua because it is of intrinsic interest as a problem in molecular physics, and because the near-IR can have a detectable (though slight) effect on near-IR absorption of solar radiation by Earth’s atmosphere. To get the flavor of some of this work, look at:
http://www.agu.org/pubs/crossref/1998/97JD03285.shtml
and the references therein. I haven’t yet found a database for O2 collisional continua that is as convenient to use as the ones provided by Courtin for N2, or by Borysow for a variety of other gases. Perhaps some of the readers here can help out. There are a lot of O2 spectroscopy papers out there to comb through and some more eyeballs would be useful.
Raypierre, re 148,
Sorry, I think I confused you. My comment in 148 was a reply to Ray Ladbury‘s comment in 136 (about my question to you in 131), not your inline reply to my question in 131.
It’s a case of ambiguous Rays.
From an analysis of world food price rises by Paul Krugman:
The corncrakes are complaining…
Re: Ray at #154:
You make many fine points, and certainly, as I hope as my post indicated, I’m not suggesting that the blogosphere could ever make up for any of the traditional routes that policymakers use to gather critical information and make decisions, but rather, they fill a increasingly important social roll of sizing up the landscape of differences between the experts. The comments between the experts are the most interesting and valuable, and even though one expert may have more credentials and expertise in a given area, and clearly recognized as the “leading” authority, dissenting opinions by other PhD’s do get traction in the political arena simply due to the fact that, at least in the U.S., that political arena is highly polarized. Reading blog exchanges between PhD’s on a given climate subject area helps to set at least give some of the background and see where the science may not be settled. For example, J. Curry’s attempt at creating a discussion on “Slaying the Dragon” was helpful in that a policymaker, or their staff could potentially discount this book, and know where the weaknesses are if any of their political opponents should be so foolish as the quote from it or reference it as a reason for doubt or inaction.
> 142
Saying I wish her luck over there, but I think she’s an optimist.
Does anyone else notice a certain asymmetry in these two sets of quotes?
“When I make a public statement about what a scientist does or does not know, I make a point of actually reading what that scientist has to say on the subject, rather than what other people say about that scientist on blogs.”
“Let me say that this is one of the most reprehensible attacks on a reputable scientist that I have seen, and the so-called tsunami of accusations made in regards to climategate are nothing in compared to the attack on Wegman.” and then “So I rose to Wegman’s defense, without being anywhere near adequately informed to get involved in a discussion on this.”
Are they unrelated? I think we should be told.
@ Heraclitus
Indeed they are not unrelated. You may find ythe context here:
http://curryquotes.wordpress.com/
Since no one has yet mentioned it: two reports out today, one on Russians drilling down to Lake Vostok in Antarctica to extract multi-million years old living material; the other on the all-time historic low Arctic ice formation for January.
Re 146 – R.Gates The majority of those setting climate related policy will hardly be able to understand the complexities of radiative transfer,
Maybe, but the underlying principles are actually quite easy (in my mind, far easier than understanding much of the rest of climate physics):
Picture smoke. Okay, if it’s more familiar, picture fog. Think about how far you can see through it – how you see more of the fog and less of other things as it gets thicker, how you see more of the closer bits of fog and less of the farther bits of fog as it gets thicker.
The fog is scattering radiation; it’s temperature doesn’t matter directly in how it affects what you see (indirectly via effects on optical properties – freezing fog is a bit different, etc.), but in net effect it reflects (backscatters) some radiation toward where it comes from, blocking radiation from one place from getting farther, to greater extents as the fog gets thicker, etc.
Now go back to smoke. Let’s make a smoke that doesn’t scatter much light, so it mainly absorbs and emits radiation; the emission increases with higher temperature. Picture how it looks over different distances with different thicknesses of smoke with different temperature distributions. For a given thickness it emits more if it is hotter; over a given distance and for a given thickness it absorbs a fraction of incident radiation, that fraction is the absorptivity of that path length; over the same path it emits the same fraction (emissivity, equal to absorptivity) of blackbody intensity, the intensity of radiation that is in equilibrium with other matter at that temperature. Thus, over longer distances or with thicker smoke, or with smaller temperature gradients, the amount of radiation seen at a given location tends to correspond more closely with the temperature at that location (and tends to be closer to the same in all directions, with little-to-no net flux in any direction); thinner smoke reveals radiation coming from farther away in amounts corresponding to temperatures found farther away.
The fog blocks radiation coming toward you from behind and replaces it with radiation coming from behind you. The smoke blocks radiation by absorbing it and replaces it with what it emits.
The gases in the atmosphere generally act like the smoke, of varying thicknesses depending on amount, type, and wavelength. Clouds act more like the smoke than the fog at longer wavelengths where emission at the relevant temperatures is significant. Temperature generally decreases with height through the troposphere, above which, in the global average at least, to a first approximation, the vertical energy flux is accomplished by radiation alone.
It was a clear and chilly night….
If I may return to that matter, I have seen comments on warming nights here and elsewhere but I still have questions. It is said and published I think that the average nighttime temperature anomaly is greater than the daytime anomaly. In addition, record low temperatures for a given place and day of the year (eg, your town and the date of 4 July) are much scarcer in recent decades than record high temperatures.
Can I say that in general, clear cool nights are not as cool as they used to be? Could this be due to water vapor alone, or is CO2 in the troposphere a cause? To what extent if any can “nights warming faster than days” support attribution? I don’t see that it can, but what does RC say?
@RGates #160, you wrote: “I’m not suggesting that the blogosphere could ever make up for any of the traditional routes that policymakers use to gather critical information and make decisions, but rather, they fill a increasingly important social roll of sizing up the landscape of differences between the experts.”
I’d be horrified if I learnt that policy makers thought, for example, that Curry’s blog, or CA, or WUWT reflected ‘the landscape of differences between the experts’. Those blogs are not dominated by experts, or except in the case of Curry, not run by anyone having scientific expertise. Even with Curry’s blog, her posts are more often pseudo-philosophic twaddle than science (or snide remarks and insinuations about her colleagues) and most of those commenting are deniers.
I would not rely on them to guage public opinion, either. They attract the same relatively small group of people.
Realclimate.org posts provide some good insights into the science and many of the comments are from informed people (and many aren’t, which is in keeping with the purpose of the site.) I’d not be as surprised or dismayed if science advisers were frequent visitors to this site (or climateprogress.org, to supplement their knowledge of technical developments etc)
On the whole, policy makers would be much better informed about the science if they used advisers who kept abreast of scientific and technical journals. And better informed about the concerns (and notions) of the public if they used market researchers who poll public opinion.
Judith Curry has finally got around to defending Gavin from her hordes of winged monkeys.
But, as is her style, she also has to have a self-indulgent dig;
“And I agree that his [Gavin’s] style on the blog often comes across as arrogant and authoritarian”
To Sou@ #167-
You make some good points, but I’m not suggesting at all that policymakers or their staff would learn any substantial science behind climate change by coming to blogs, but rather, to learn a bit more about the real dynamics of who the players are, to size them up a bit, and learn how to “read between the lines” as it were, when comparing the differences of opinion between them. Certainly in the blogosphere, sites will have more or less value, and a different kind of value, than others in sizing up the players. It certainly it speak volumes about Trenberth that he refuses to engage at all here (I’m not saying this is a bad personal choice of his). But like it or not, this forum (i.e. the blogosphere) is here to stay and grow in it’s influence and importance in the ways I’ve outlined above. Nothing will take the place of simply picking up and reading credible journals to learn more about the science, but to learn a bit about the differences in perspective that the people behind that science have, the blogosphere is becoming an essential tool. Understanding those differences, and the basis for it(unsettled science vs. raw academic talent and knowledge) can be vital to settling in on sound climate policy and defending it against political opposition.
Raypierre (#134),
Not looking for the last word at all. Just exploring a challenging claim.
Suppose the rain in Spain fell only on the plain. All the calcium ions were leached away and never replenished from erosion from the mountains. Then, no matter how heat might accelerate formation of limestone, none would form. We currently have a situation where water evaporates from the Indian Ocean but very little rain falls down wind on the Sahara. I wonder if a model that is not one dimensional might turn up something that goes counter to your expectation of enhanced weathering?
Where I was going in the last comment was that sometimes very good scientists (Rees was elected President of the Royal Society) make ‘trust me’ statements. These statements don’t have value as scientific statements but do give prominence to the issue just because of the manner in which they are put.
A random question:
How is the earth’s crust modelled, and does it have any meaningful effect on how heat is distributed around the earth in any climate change scenarios? Could it, for example, have any effects at regional level, or (mis-?)modelling have an effect on thermal inertial on earth and the transient response to climate change?
Or is it simply too small to bother with when compared to heat distribution (and currents) throughout the oceans?
Apologies if this is the wrong place to ask; perhaps some kind soul will point me in the right direction, even if it’s just the exit.
We all did the elementary experiment with the thermometer in the ice bath over the Bunsen burner: the temp stays at 0 until all the ice melts. I’m wondering if anyone has done a quantitative analysis of how much of a moderating effect all the polar ice melting is having on global temperatures.
I could just about calculate the total heat of crystallization involved, but then I’d have no idea whether that quantity was negligible or significant. Thanks for reading. Cheers.
@ The Raven #159: No single extreme weather event can be blamed on climate change, as you say, but I agree: it sure does look like we can attribute a largish part of the blame for the recent rash of extreme events on AGW. Has anyone tried to quantify this?
Disclaimer: I have a vested interest in finding out more. Cyclone Yasi just went over the top of us.
How are chaotic oscillations included in climate models? This came up in a discussion about “global warming has stopped.” My understanding is that, since natural internal variability is of greater magnitude than greenhouse forcing, it’s no surprise to see periods of relative cooling or no trend, and that these are predicted to continue over the 21st century. The enhanced greenhouse effect does not stop the oceans sloshing about. Someone told me that the models are all wrong because they can’t capture chaos. So I did a little reading (I’m a total layperson), and found things about the period doubling cascade and other routes to chaos. Can anyone point me in the right direction, or give a short explanation on modelling chaos and models acheiving ENSO etc. oscillations and interannual variability?
In my book-in-progress on sea level rise, I’d like to describe the 300-pp. U.S. Climate Change Science Program’s January 2009 study, “Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region”, as “one of the most recent and most comprehensive US Government reports on sea level rise.” Is this an accurate statement? If it is NOT, please let me know off-list at huntjanin@aol.com.
R. Gates, I believe you missed my point. Why should policy makers turn to blogs when they can ask (and have asked) the National Academies for advice, and that is precisely the reason why the Academies were founded? Some “science” blogs are a joke. Some are unreliable. Some (like Realclimate and Tamino) are absolutely stelar. Do politicians and policy makers have the experience and judgment to know which is which? On the other hand, the Nantional Academies have been a reliable source for synthesizing scientific consensus for policy makers for 150 years.
When faced with a strong consensus, I think it is a natural human tendency to look for dissenting opinions. That is not how science works. Often in science,when you have a strong consensus, the only voices it does not include are the cranks or the ideologically blinkered. The cranks are much easier to find in the blogosphere than in a NAS study. Do policy makers know the difference? If so, why are they looking to the blogosphere in the first place?
The best of the blogs can play a critical role in educating people about the science. The worst of the blogs serve no useful role other than as objects of ridicule. It is pretty clear to me that a lot of our elected officials cannot distinguish between the two classes.
154 Ray Ladbury: People who “read between the lines” are jokers and provokers, not scientists. “Reading between the lines” is just a means of provoking anger by refusing to hear that which is written on the lines. You can’t read where nothing is written. Provokers are people who are afraid to express their own anger, so they go about getting other people to express anger for them. Provokers are and have a psychological problem. Just avoid them and refuse to communicate with them, for your own good.
“And in disputes between scientists, it is not a matter of one scientist, one vote.” That much is true.
“You have to take into account the publication records of the scientists involved”
False. Scientists do not have a proportional vote because no human has a vote. Only Mother Nature has a vote. There is no democracy. Nature is the absolute dictator. Science has nothing to do with popularity.
Do not do a Thomas Kuhn [The Structure of Scientific Revolutions] or a Ryghaug and Skjølsvold or a Jerry Ravetz. Physics is not about sociology. Physics is about rock-hard physical reality and nothing else. The “current consensus” is a guide only to those who have no hope of understanding it, whatever “it” is. Lawmakers ought to understand the science, and that is a moral “ought.” Without understanding, they cannot make adequate laws.
Edward Greisch,
I agree that nature ultimately gets the only vote that counts, but the problem is that she plays her cards very close to her bosom. Unfortunately, policy must be based on prognostication, not history, and scientific consensus is the best guide we have for prognostication. I’ve stated before why I think this is so–e.g. that those with the best understanding of their field with usually be the most prolific and influential publishers in that field.
And I do not think that lawmakers need necessarily understand “the science.” That may be too much to expect given that they must pass laws affected by all areas of science and technology. However, I think they have to uderstand science (e.g. method and why science works) well enough to identify and listen to the true experts in the field.
A rare instance of a denier propagandist feeling consequences:
http://www.desmogblog.com/weaver-sues-tim-ball-libel
Particularly gratifying is this bit:
MalcolmT wrote: “No single extreme weather event can be blamed on climate change …”
No weather event, extreme or otherwise, can be “blamed” on any single cause, including global warming.
All weather events arise from a multitude of causes and conditions.
And global warming is now a pervasive, inescapable condition that affects all weather events.
No, changes in temperature and water vapor have never been causes of weather, and you alarmists are not going to get away with changing that!
[Response: Oh golly, thanks for opening my eyes on that! And here I always thought heat waves had something to do with, well you know, the temperature sort of getting higher. –raypierre]
Unfortunately, policy must be based on prognostication, not history, and scientific consensus is the best guide we have for prognostication. – Ray Ladbury
Her latest.
With respect to the Brisbane flood this is why it is so important to them to claim the flood was not unusual when compared with past floods. The decision for new flood mitigation should exclude AGW considerations. Since the recent Brisbane flooding caused significant damage and took lives, past decisions on flood mitigation are under their microscope. The historic record led experts to propose additional dams. Australians rallied against them and they were not built. This is a political opening, and a means of implying the opponents of the dams are murderers, which has been done on blogs.
So in a way the strategy is to take the weather changes they know will happen because of AGW and using any catastrophe they cause as a means of defaming environmentalists, who chose lung fish over human beings.
A real possibility is the flood was likely caused by a weather event that was unique. The final analysis will tell the story. The flood-mitigation infrastructure failed to hold the flood level to the predicted level, which could be an indication something outside the historic record took place.
But to them the fix is simple: build the dams the historic record indicated were needed.
[Response: Hang on a second. I don’t know the particulars in Australia, but dams historically haven’t helped mitigate flooding; quite the opposite. It ain’t so simple.–eric]
If only politics were like science, and simple “consensus” were enough to move policy forward. If that were the case, there might not need to be letters like this one, written by scientists to members of Congress:
http://thehill.com/blogs/e2-wire/677-e2-wire/141453-scientists-put-aside-politics-and-focus-on-climate-science
Like it not, the Blogosphere is the new global town hall, and both scientist and politician needs to move effectively through this new space…
Re #168,
So Curry “defends” Gavin with an ad hominem attack of her own? How sweet. Not the way to build bridges.
How about a sincere and unequivocal defense Curry? No rhetoric, no innuendo– you know, just doing the right thing for the right reasons.
raypierre, re your response in #148. To clarify, I’m pretty sure you are saying that molecules with no dipole moment (like N2 and O2) will absorb virtually no IR radiation, but if one of those molecules collides with another molecule its physical configuration might be misshapen, causing a dipole, so that at the instant of collision it can indeed absorb IR radiation into its vibration or rotation energies. Did I get this correctly?
If so what is the prevalence or likelihood of such absorption, given that the average N2 or O2 molecule is colliding with something extremely frequently? Is there something akin to an Einstein coefficient that puts a (low??) probability or (high??) half-life on such collision coincident absorptions? Or does the nature of the physical collision play a part also?
Thanks.
[Response: Yes, that is how collision induced absorption (CIA) works. The quantification of the probability of absorption is given by the binary absorption coefficient tables I linked to in one of my earlier answers. See the papers on the Borysow site I linked to for details of how the quantum mechanical computation is done. –raypierre]
Bob (Sphaerica), I might suggest the term “Planck function radiation” which might unwrap the semantic differences with “blackbody radiation.” Blackbody literally, as you say, seldom exists and is an ideal rather than a fact. But planck function radiation is the exact same general process as blackbody without the nitpick baggage. [Though if the meaning is understood, “blackbody” is much easier to write and say…]
JCH #181:
I’m not sure I’m happy to have clicked your link…
I think this is another for curryquotes. After reading Trenberth’s essay thrice, I still can’t see how she could interpret that as saying “scientists should call the policy shots”.
Just a follow-up to post #182 –
Scientists can write all the letters they want, but the political reality, like it or not (and I don’t especially) is that money ultimately runs D.C.– not logic and science. See this illuminating article from today’s LA Times:
http://tiny.cc/jvhpg
So, if you are of the mind-set that AGW is not just real, but likely to cause serious problems, then an equally serious and frustrating problem is the way politics works. In such a scenario, money trumps all, until nature does.
181, eric in comment: dams historically haven’t helped mitigate flooding; quite the opposite
In what area of the US did the TVA dams increase flooding? Did the dams of China (Three Gorges Dam et al.) cause increased flooding in China in 2010 compared to pre-dam eras?
The levees along the banks of the Mississippi protect towns and croplands from most floods, but increase the extent of the flooding in the 3% or so most extreme floods. But the upstream dams all over the region from the Appalachians to the Rockies have not heretofore (to my knowledge) been said to have been responsible for increased downstream flooding.
How about dams in California, in the San Gabriel Mtns and the Sierras? Have they increased the depth, extent, frequency or economic costs of flooding?
151, Hank Roberts: Look back at JC’s blog (or, shudder, if you follow it regularly, which I certainly don’t): she’s started one topic after another attempting to reach some common agreed facts — and each has gone the same way, badly.
FWIW, I agree.
Apologies if this appears twice.
I have a question about modelling chaos. Someone told me that models are wrong, because they can not accurately represent the chaotic oscillations of ENSO events and inter-annual variability. This doesn’t seem to be right – I read of something called the period doubling cascade as a “route to chaos.” Is anyone able to sum up modelling chaotic oscillations, and how they are fed into climate models, in lay terms?
[Response: I can’t, but of course, any time you hear the phrase “models are wrong” immediate red flags should go up, because it indicates that the person making the claim doesn’t really understand what modeling is all about in the first place.–Jim]
Inevitable. See the heroic efforts at Science of Doom for an illustration of the futility of a genuine skeptic’s attempts to bring deniers to the proximity of reality. They don’t want to know. Engaging with them is a guaranteed waste of time.
> have they increased
Or decreased, or led to development later damaged in the floodplains ….
Yes.
The area has been extensively researched. This keeps coming up as though nobody had talked about it. Curious, eh?
http://scholar.google.com/scholar?q=dam+floodplain+consequences+costs
[Response: Hang on a second. I don’t know the particulars in Australia, but dams historically haven’t helped mitigate flooding; quite the opposite. It ain’t so simple.–eric]
Your logic is about to be put to the test in Australia, and I agree that it is very complicated. If you look at the 1983 flood level versus the 1974 flood level, there is an obvious difference. Some would argue part of it was the flood-mitigation provided by the Somerset Dam, which was finished in 1959. Obviously an accounting of the water has to be included.
After the 1974 flood a comparison was made, and they decided to build the Wivenhoe Dam. A later analysis indicated the Wivenhoe Dam needed upgrading. They completed a phase of that in 2005. In mid-January of 2011, the Wivenhoe failed to hold the flood level to the prediction: which I believe was 2 meters under the 1974 crest.
Many bloggers looked at that graph and concluded the 2011 flood was much less severe than either 1974 or 1893 (Curry and Pielke Jr.are examples,) and that claim has been made in the comments section here. I do not agree with them.
What they will argue is building the dams the public refused to build in past decades would have mitigated much of the 2011 flood in Brisbane.
If dams do not mitigate flooding, as you say, then they could have converted the flood-mitigation components of both the Somerset and Wivenhoe Dams to water storage. I think that is a tough sell. The 2011 flood would have likely topped 1974, and possibly 1893. With no mitigation capacity, all the rainwater flowing into the dams would have been sent straight to Brisbane.
An example, from a site with extensive research documented:
http://www.dams.org/docs/kbase/contrib/opt175.pdf
“Summary
Large dams have provided extensive benefits during the past 60 years: for example, fueling the powerful economy in the Western United States through cheap power, irrigation and municipal water supplies. There has also been a dark side of these massive civil works projects that were not fully comprehended during the early project planning process. This is not surprising since ecosystem response and physical processes at the basin scale are immensely complex and could not have been fully anticipated with the state of science in the 1930s and 40s. The implementation and management of large dams is still a relatively new science, compared to the time frame necessary to detect and understand some negative impacts occurring at the watershed scale. This paper attempts to summarize the unforeseen or unanticipated environmental consequences of these projects, as well as potential ramifications to the overall performance of the project. One of the important management concerns is to ensure that there is a viable decommissioning strategy for the dam at the end of its design life, and including this cost in the life cycle cost-benefit analysis….”
Re 170 Chris Dudley – in climatic equilibrium, precipitation balances evaporation in a global time average. Imbalances will of course exist regionally and temporally. The present H escape to space is quite small; there is not much of a H2O sink at high altitudes – well, actually CH4 oxidation is a source, but again, small relative to surface fluxes of H2O (etc. for photosynthesis, respiration)…
I haven’t seen the fig 5 you wrote of, but I’m guessing, that maybe the higher RH (relative humidity) shown at 25 km is in the stratosphere and not expected to be a significant source region of precipitation reaching near the surface. Precipitation generally falls from clouds, which are generally local maxima in RH in an otherwise generally unsaturated troposphere (in fact the precipitation helps produce dry air by removing H2O – consider what happens when the air in a cloud sinks/warms, without the same total amount of H2O that was present when it formed).
Of course if in some odd scenario rain did not reach the surface but hail did, then the hail fall would be what balances evaporation (setting aside frost/dew/etc.).
It will be interesting to see what Eric says, but keep in mind that not all dams are built with flood mitigation in mind. For instance, the dams along the Columbia are all (to my knowledge) traditional hydro (Bonneville, Grand Coulee, and others) or run-of-the-river dams (such as the John Day) built both for hydro and to raise the level of the river behind the dam to reduce irrigation costs for nearby farms (they don’t have to pump it as far).
So a more specific question is how well do dams built primarily for flood mitigation work? In the case of the Wivenhoe Dam we’re probably going to learn a lot over the next few years, I’m sure it’s going to be intensely studied for some time.
178 Ray Ladbury: The scientists should write the laws. Which scientists? Mike Mann, Jim Hansen, and RealClimate. Jim Hansen should run for the US senate. The laws will not be correct until the scientists have political power. That is why we humans are in danger of going extinct. Scientists may be given power as soon as it is too late to do any good.
I know that scientists don’t want political power. It just isn’t in our job description. Nor does it fit our personality type. We don’t have the numbers of scientists required to form a voting block. etcetera.
Politicians “have to understand science (e.g. method and why science works) well enough to identify and listen to the true experts in the field.” But they don’t. They understand getting money to get re-elected. So evolution, alias gigadeath, is going to happen. If we are lucky, the average math IQ will go up a few points.
Instead of writing letters to congress, as in
[http://thehill.com/blogs/e2-wire/677-e2-wire/141453-scientists-put-aside-politics-and-focus-on-climate-science]
the scientists should write a proposed law and proposed implementing regulations and explain what the law and regulations would do if implemented. The economic and social differences from BAU should be included. The scientists should act as a shadow government, as some out-of-power political parties do.
I should say “not with flood mitigation as a primary purpose…”
Obviously when floods threaten, river managers will do what they can with the tools they have…