I wonder if Alan could clarify a bit his point no. 2: "The TTAPS model had no heat capacity at the surface, so it was a model of the response in a continental interior. I think what you plotted was our global average response. The globe is 70% ocean. So the global average response would be more than 10 times smaller than the middle of a continent." I do recognise the issue of the shading impact of nuclear explosion dust clouds having huge impact on the continental interiors, but not globally. However, what is the effect on the overall oceanic albedo as the oceans do have plenty of supersaturated air masses that are highly aerosol deficient. Could supply of nuclei for condensation create new clouds and cloud whitening effects to the extent Stephen Salter's ideas. Was the cloud whitening and cloud formation over oceans included in your simulations? Or was it just the dust shade?
How about wind drift, surely nuclear war does not stop the winds and these will scatter nuclear dust much like volcanic dust? I agree that local effects of pulverising mountains for dust clouds are severe, and one of the problems is that most tall mountains reside on the western edges of continents, leading to dust fall and biggest effects to highly populated areas. Professor Teller was always an advocate of thermonuclear explosives for weather or climate modification. Would you consider it a possibility to ameliorate the worst heat waves or supersaturated ocean air by nuclear devises when heat trapping water vapour builds up dangerously high in the air as climate gets ever warmer? Note that biological systems are sensitive to weather extremes, not very much to the rising average temperatures? (1.) Can we manage 2 - 4 - 6- 8- 10 degree warmer climate by occasional explosions when system is most overheated to allow the biological systems to recuperate. Not continuously suppressing the temperature, but when the weather is too hot for organisms and ecosystems. (2.) Can we remove supersaturated water vapour from the atmosphere, say above the Pacific Ocean, by explosions providing seeding nucleation centres to (i) flush water out and hence reduce its greenhouse gas impact, and (ii) to generate sunlight reflecting clouds or cloud brightening above oceans whenever air is supersaturated. I became intrigued to Alan's response as I could not see these issues addressed in his reply. I do recognise the accumulation of radiochemicals in each explosion, which is a major issue but if there is an immediate threat to ecosystems and evidence of them dying in heat, or lack of rain, would these measures be agreeable by rise in cesium and iodine. Regards, Albert Date: Thu, 27 Sep 2012 15:13:55 -0400 Subject: Re: [geo] Re: nuclear winter, from the archives From: [email protected] To: [email protected] Re: [geo] Re: nuclear winter, from the archives Here’s my take on the exchange: It seems to me the core of the difference in the use and interpretation of a metaphor to describe scientific results—and arguing over this can unfortunately obscure the significance of the scientific work. Russell is doing what scientists often do, namely taking words literally. So, TTAPS did project freezing of the whole world—I don’t recall them saying that it was just the center of continents, etc.--with temperature predicted to go way below zero (and the accompanying article on the ecological response did take the TTAPS results directly). That is what Russell is saying is meant by the phrase “nuclear winter.” When the 3-D models were run, etc., the results were variously called a “nuclear autumn,” “nuclear drought,” etc., so the literal result of TTAPS description was indeed modified in the SCOPE assessment. But the SCOPE assessment, in addition to describing the very sizeable climatic disruptions, also reiterated that the direct effects of such an exchange would be horrific (this was generally previously understood) and also spent time on a point not well developed at the time, namely that the likely disruption of the emerging global economy (in medicines, grains, fertilizer, energy, financial markets, and more) would also lead to horrific consequences, and this was whether there was a climatic effect or not. Together, the various dire outcomes could be characterized, at least in metaphorical terms, as a “nuclear winter” and so the term from TTAPS persisted, though was not generally used in the scientific assessments describing all the impacts. Basically, what was made clear was that large-scale nuclear war would be a real disaster for combatants and also, importantly, for non-combatants, and the consequences would be significantly worse than the scenarios being used in some of the civil defense planning that envisioned getting into shelters for a week or so and for planning for how to restart postal operations. As Alan states in his note back to Russell, the quantitative results of his recent work are, of course, different than for the global nuclear exchange. Thus, interpreting the words “nuclear winter” literally, this means the term is no longer applicable (indeed, as it was not really literally applicable after the SCOPE assessment). However, from the perspective of the types of consequences that would result from a nuclear exchange, the consequences from Alan’s smaller exchanges, so the mix of the direct and indirect effects (indirect effects include those arising from lower light levels, modified weather, and over time, departures from normal conditions—and then subsequent impacts) would be of similar significance, at least for some, possibly large, areas. From this perspective, then, continuing to portray the significance of the changes (in particular that there were environmental consequences over and above the direct destruction and fallout, even if the quantitative aspects were different) as “nuclear winter” is at least metaphorically justified, for the term indicates that the resulting conditions would be very hard and difficult to deal with (whether caused by a cooling few degrees or a few tens of degrees, the loss of a crop is the loss of a crop). My personal opinion is that scientific results are best described, at least to other scientists, using words literally, and I generally think using metaphors should be avoided in scientific discussions. Metaphors can, however, be useful to convey the significance of results to policymakers—and Alan’s papers are aimed at speaking to policymakers as well as scientists. In the cases described in Alan’s papers, which involve nuclear exchanges between mainly low-latitude nuclear-capable nations, I actually wonder, however, whether “winter” is the most appropriate metaphor because “winter” is experienced so differently at low as compared to in mid-latitudes--”drought” might be a better metaphor (caused by the stabilization of the atmosphere resulting from smoke-induced heating aloft). In any case, this distracting arguing about the label really obscures what the scientific results show, which is that, in addition to the horrific direct effects, nuclear war can lead to significant indirect effects, impacting not only those who are struck by the bombs, but those well beyond (and this is especially important because of the limited food reserves now available around the world—basically the world’s nations don’t seem to store, for example, a full growing season’s worth of grain). Together with all of the other consequences of nuclear war, the studies thus indicate that all nations, whether combatants or not, should have a strong self-interest in ensuring that even a relatively small nuclear exchange does not take place and the leaders of nations holding nuclear weapons should be made aware of this. Mike MacCracken On 9/27/12 8:49 AM, "Fred Zimmerman" <[email protected]> wrote: Does anyone care anymore what Carl Sagan wrote 30 years ago? Half the population is too young to even know who he was. I question whether anyone who was under 30 in 1986 even remembers anything about the early debates. Surely what is more important now is our current understanding of the climate effects of a nuclear exchange, and even that is, frankly, not all that important, since the proposition that "a nuclear exchange would be bad" is amply supported by a thousand other variables. On Wed, Sep 26, 2012 at 9:59 PM, Russell Seitz <[email protected]> wrote: Dear Alan; You are trying to deny the elephant sized apple in the room-- your effort to redefine 'nuclear winter ' downward amonts to raw semantic aggresion in the light of how Carl Sagan made its quantitative meaning perfectly clear by telling a national television audience it was "precisely" like the K-T impact. That astronomical megahype leaves you, as the neologism's defender, to explain to us why you and a few true believers are still enamored of the phrase when both parameter studies and more sophisticated models have so thoroughly defrosted it? The numbers talk, even if you don't like the look of them side by side - TTAPS publicists( Porter Novelli) were retained before the paper was published to create a cold war factoid by applying the tern to a fruit salad of over twenty ( not three) scenarios. Some were based on non-existant arsenals and others injected no smoke or carbon black into the atmosphere, let alone the 5 Tg Alan has modeled. The failure of Sagan to incorporate ocean thermal mass from the one dimensional model TTAPS was one of many reasons Steve Schneider took him to task in Foreign Affairs. Another was Sagan's insistance in its pages that just the sort of low-yield regional exchange Alan has modeled " a pure tactical exchange, in Europe say" fought with sub-Hiroshima yield neutron bombs would still precipiate a global deep freeze. History is full of prophets of doom who fail to deliver, but I appreciate that you have wisely refrained from emulating TTAPS most unrealistic parameterizations in your work. So would I, because the early models larger-than-life fuel loadings and arsenals have long since been discredited . perhaps you should recall the sober title of the Ambio article in which Paul Crutzen first broached the subject ; Twilight at Noon, That phrase pretty well nails what you've modeled, and may indeed explain why first broad-ranging study to review the TTPS results, the 1985 NAS /NRC reportThe Effects on the Atmosphere of a Major Nuclear Exchange does not even contain the expression 'nuclear winter , and succesive generations of more advanced models all failed to reproduce the " apocalyptic predictions" publicized at the Cold War's height. Having known Sin at Hiroshima, science was bound to run into advertising sooner or later - anybody can tell a systems programmer to paint a model sky pitch black but justifying such an action on retrospect is an altogether different matter.. On Wednesday, September 26, 2012 7:49:34 PM UTC-4, Alan Robock wrote: Dear Russell, You are comparing apples and oranges, or apples and something that is not even fruit. Are you doing this on purpose to fool readers or did you not even read the papers and understand what was done? Here are the differences: 1. TTAPS looked at three scenarios of global nuclear war, and our scenario was only 100 Hiroshima size weapons, with a total explosive power of 1.5 MT (which could produce 5 Tg of smoke). So the scenarios differ by factors of 67 to 6,667 in terms of explosive power and about 100 in terms of smoke generated for the TTAPS baseline case. Why would you expect the response to be the same? 2. The TTAPS model had no heat capacity at the surface, so it was a model of the response in a continental interior. I think what you plotted was our global average response. The globe is 70% ocean. So the global average response would be more than10 times smaller than the middle of a continent. Do you think anyone will be fooled by your figure? Wouldn't you be surprised if the response did not differ by factors of 100 to 1000? Alan Alan Robock, Professor II (Distinguished Professor) Editor, Reviews of Geophysics Director, Meteorology Undergraduate Program Associate Director, Center for Environmental Prediction Department of Environmental Sciences Phone: +1-848-932-5751 <tel:%2B1-848-932-5751> Rutgers University Fax: +1-732-932-8644 <tel:%2B1-732-932-8644> 14 College Farm Road E-mail: [email protected] New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock <http://envsci.rutgers.edu/~robock> On 9/26/2012 6:32 PM, Russell Seitz wrote: Here are the time-temperature curves of the 1983 'nuclear winter ' model, and those of Robock et al. 2007 , superimposed on the same scale: http://s1098.photobucket.com/albums/g370/RussellSeitz/?action=view¤t=TTAPSROBOCK.jpg <http://s1098.photobucket.com/albums/g370/RussellSeitz/?action=view¤t=TTAPSROBOCK.jpg> -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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