========================================================================= Date: 2 January 1994, 10:35:07 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Indonesia goes nuclear John McCarthy posts (concerning Indonesia's plans to build a nuclear power plant): >If they can do a 600 megawatt plant for $3 billion, it will be an >economic win. ... Do you have some substantiation for this statement? I would like to see the calculation which shows this is economically superior to building natural gas fueled power plants, particularly in light of Indonesia's abundant supply of natural gas. I suspect this decision can not be justified on purely economic grounds. James B. Shearer ========================================================================= Date: 12 January 1994, 17:09:06 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Re: Extinction Events Leonard Evens posts: >It seems the me that the thought that the biosphere is going through >one of the few major extinctions in the history of the earth should >give anyone pause to think. ... How certain is it that this is in fact occurring? What is the definition of a major extinction? How many have there been? What is the definition of a minor extinction? How many minor extinctions have there been? What is the normal extinction rate? What is the current extinction rate? What is the extinction rate as the earth goes into and out of ice ages? James B. Shearer ========================================================================= Date: 16 January 1994, 22:37:39 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Re: Extinction Events Leonard Evens posted: >It seems the me that the thought that the biosphere is going through >one of the few major extinctions in the history of the earth should >give anyone pause to think. ... I asked: > How certain is it that this is in fact occurring? ... Leonard Evens replied: >I strongly recommend Edward Wilson's `The Diversity of Life' to anyone >who is interested in answers to some of these questions. ... > >A major extinction is something like what happened 65 million years >ago when the dinosaurs (along with many other species) disappeared. >I believe that there having been seven (including the current one) >major extinctions during the history of our planet. > >Wilson presents a very convincing argument that we are presently in >another such extinction. As best I can tell, this view is shared >by almost all biologists working in this or related areas. ... Andrew Taylor replied: >Look at "Extinction" by David Raup, Norton(1991). Raup is a well-known >paleontologist specialising in statistical questions. This book covers many >of your questions. Its well written and available in paperback. >E.O. Wilson's "Diversity of Life" would be another good starting point >also I notice in paperback now. Wilson argues that we are in the process of losing 10-25+% of the earth's species due to human activity (p. 342). Although he repeatedly states this is a sixth great extinction he presents little material on past extinctions to justify this. Raup on the other hand looks at past extinctions and does not attempt to estimate current extinction rates. He does estimate extinctions killing 10% of species will occur every 2 million years, extinctions killing 25% of species will occur every 10 million years (figure p. 85, the figure is for marine organisms however Raup appears to assume the curve for all species would be similar). Raup suggests an arbitrary cutoff of 65% species kill as the definition of a mass extinction (p. 84). Hence the books taken together do not support the assertion that we are currently going through a mass extinction. Both books count 5 (not 6) prior mass extinctions in the Phanerozoic or last 600 million years (not the history of the earth). I found the Raup book more readable (and less political) than the Wilson book. However the Raup book does contain two blatantly false assertions which cause me to have some doubts about its reliability. On page 48 Raup asserts that "Theoretically, casinos could make a profit by offering an even-odds game as long as they put limits on how much players bet." and on page 50 "Most scientists and philosophers now agree that nothing is truly random in the natural world." James B. Shearer ========================================================================= Date: 18 January 1994, 16:32:30 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction events Leonard Evens posted: >Wilson presents a very convincing argument that we are presently in >another such extinction. As best I can tell, this view is shared >by almost all biologists working in this or related areas. ... When I questioned this he posted: >I feel uncomfortable, as a non-biologist, debating another non-biologist >about these matters. As I have noted elsewhere, it is very easy to >misunderstand important issues in a field one does not work in because, >lacking the required depth, one doesn't get the context right. Perhaps then you should be a bit cautious about declaring a view is held by "almost all biologists ..." (with the implication that anyone who disagrees is some kind of nut). Leonard Evens also posted: >I was also inaccurate in using the term `history of the earth', >and should have restricted this to the 550-600 million years of >the phanerozoic eon. This lapse is perhaps understandable since >very little is known of life on earth before the Cambrian Period, >and in terms of diversity of life, I think it is correct to say >that almost everything interesting has happened since then. It is >not called the `Cambrian explosion' for no reason. The "explosion" was in the fossil record. I see no reason to believe all interesting events are recorded in the fossil record. Leonard Evens also posted: >I think I will stick with my contention that Wilson considers what >is happening now a `major extinction spasm', one of 6. ... > ... I don't believe I misunderstood Wilson on this point. I agree that Wilson says this (as I posted before). I don't agree that he makes a convincing case. Leonard Evens also posted: >When I get time, I will read Raup and see if he disagrees in any >significant way with Wilson. Raup's book is quite different in tone. Consider the following quotes from Raups discussion of rain forests (p. 134-137). "We are accustomed to thinking of tropical rain forests as the stable product of slow evolution over hundreds of million years. They are not! The geological record indicates that rain forests have occurred only spottily in space and time, because they require an unusual set of circumstances, which have existed for only relatively short periods." ... "An interesting sidelight on the rain forest phenomenon is its bearing on biodiversity. Today, a majority of plant and animal species live in the wet tropics. If today's rain forests were lost, global biodiversity would drop. Because of fluctuations in the rain forest presence in the geologic past, global biodiversity must also have fluctuated; it was probably both higher and lower than it is today." Raup goes on to discuss "controversial" evidence that rain forest area was much less (84%) on occasion in the recent past (50000 years). The general impression I got was that the ecosystem can get along fine without rain forests. Nothing like this appears in Wilson's book which discusses rain forests at length. James B. Shearer ========================================================================= Date: 18 January 1994, 23:18:04 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction Events I posted: > ... However the Raup book does contain two blatantly false assertions >which cause me to have some doubts about its reliability. On page 48 >Raup asserts that "Theoretically, casinos could make a profit by >offering an even-odds game as long as they put limits on how much >players bet." ... Len Evens asked: >Just what was the context in which Raup asserted incorrectly that the >house would win on the average in a game with even odds? >Was this just a random comment or was it essential to his argument. It was in the middle of a chapter entitled "Gambler's Ruin and Other Problems" which contains some elementary expository material on random walks. Raup makes some additional errors after the assertion I quoted. Nothing in particular depends on it, it just made me wonder how much I should trust Raup in other areas. Len Evens added: >It is not uncommon for people to go astray when they stray beyond their >expertise, as postings in this newsgroup often illustrate. Well according to the book jacket, Raup is a "statistical paleontologist" at the University of Chicago. Considering the number of subtle errors it is possible to make while applying statistical methods to imperfect data sets it would be reassuring if Raup appeared to have a solid grasp of elementary probabilty. James B. Shearer ========================================================================= Date: 19 January 1994, 18:19:34 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.enivronment X-Post-Me: Yes Subject: Extinction Events I posted: > Raup goes on to discuss "controversial" evidence that rain >forest area was much less (84%) on occasion in the recent past (50000 >years). The general impression I got was that the ecosystem can get >along fine without rain forests. Nothing like this appears in Wilson's >book which discusses rain forests at length. Andrew Taylor commented: >I'm not sure why you think Wilson needed to discuss this. I would >have thought the distribution and extent of most habitat types has >differed greatly over geological time spans The estimates Wilson gives for the number of species currently being lost due to human activity are indirect, being derived from estimates of the amount of habitat destruction. For rain forests he estimates that half of the prehistoric rain forest area has already been destroyed (as of 1989) and half of the remainder is likely to be destroyed by 2022. He calculates that this will lead to the extinction of 10-25% of rain forest species (p. 274-278). This represents a large fraction of his estimates for the overall loss of species. Wilson claims this level of species destruction is unprecedented in the last 60 million years. Obviously the force of this argument is lessened if it should turn out (as Raup suggests) that 84% of rain forest area has been lost due to natural causes several times in the last 50000 years. Andrew Taylor also commented: >I take it by "the ecosystem" you mean the biosphere - all the life on >earth. ... You are correct, I should have said biosphere. Andrew Taylor also commented: >I'm not sure what you mean by get along fine. If you mean that some life >will remain on earth thats certainly true. If you mean that the majority of >species outside the rainforest will survive, that might be true. >Neither are comforting or useful observations. My impression was due in part to the following quote from Raup (p. 134-135). "Fred Ziegler, a paleogeographer and climatologist at the University of Chicago, has estimated that, during the 350 million years since diverse land floras first evolved, tropical rain forests have flourished for only about a quarter of the time." I interpreted this as meaning extensive rain forests are not required for a healthy biosphere. Btw what would be a comforting or useful observation? James B. Shearer ========================================================================= Date: 19 January 1994, 19:35:49 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Re: Extinction Events Len Evens posted: >It seems the me that the thought that the biosphere is going through >one of the few major extinctions in the history of the earth should >give anyone pause to think. ... I queried this. Eric Carruthers posted: > ... The fact that you are asking such questions probably means >you are already ignoring what seems to me to be obvious... ... Is it obvious to you that the human impact on the biosphere is causing more extinctions than going into an ice age would (as is required for it to rank with the "big five" great extinctions)? It is not obvious to me. It seems reasonable to believe that humanity is currently causing an extinction event. To assert it is a great extinction seems at best highly premature. James B. Shearer ========================================================================= Date: 19 January 1994, 19:48:11 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: biodiversity A number of people have posted comments to this group along the general lines of "biodiversity is good". Is this really what you believe or would a more accurate statement of your beliefs be "the natural level of biodiversity is optimum and should not be disturbed"? In other words would it be good or bad for humanity to raise biodiversity above natural levels? James B. Shearer ========================================================================= Date: 20 January 1994, 16:02:55 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction Events I posted: > Wilson argues that we are in the process of losing 10-25+% of >the earth's species due to human activity (p. 342). ... Alan McGowen commented: >A key point which Shearer did not mention is that these are estimates for >the loss *within the next few decades*, not a projection of total losses >that will occur over the (unknown) duration of the extinction episode. They >are also estimates based on rates of habitat destruction and alteration >and omit other causes of extinction, such as pollution or effects of >introduced species, which are at present minor by comparison. ... > >No one knows how deep this mass extinction could go over its entire duration; >it depends on how large anthropogenic stresses become and how long they last. >It also depends on many ecological unknowns. Wilson's estimate should be taken >as an estimate of the losses we can expect to see in the *near* future. He >makes this clear in the context. It is not an estimate of the worst that could >possibly happen, nor of the total loss that will probably happen. ... Wilson states (The Diversity of Life, p. 342 (end of chapter 14)). "Finally, the question of central interest is how much of the world's biodiversity we can expect to carry with us out of the bottle- neck fifty or a hundred years hence. Let me venture a guess. If the biodiversity crisis remains largely ignored and natural habitats con- tinue to decline, we will lose at least one quarter of the earth's species. If we respond with the knowledge and technology already possessed, we may hold the loss to 10 percent. ..." I read this as an estimate of the total loss. Alan McGowen also posted: >The 10-25% loss within a few decades should be read as a vital sign, a >prognostic, not as the phenomenon itself. ... Actually Wilson estimates rain forest habitat losses over the next few decades. The species losses which he derives from this will lag the habitat losses (perhaps considerably) as a new equilibrium is reached (Wilson is vague about how long this will take, perhaps because he feels it is not accurately known). If the habitat losses were temporary the full species losses would not occur. For example in the letter by Ehrlich which you posted: >While some dispute the connection between extinction rate and >habitat loss by citing the fact that "only" three forest birds >went extinct during the destruction of the Eastern United States, >it must be pointed out that that deforestation was only >transitory. > >Clearing peaked around 1900, and regrowth had occurred by the >middle of this century. If the maximum clearing had been >permanent, half or more of the bird species would have gone >extinct. (Btw does anyone know how many forest bird species there were originally?) This appears to indicate a considerable lag. (I am aware that tropical rain forest is not thought to be as resilent.) I also believe the assumptions Wilson uses to derive species losses from habitat losses are debatable. However even accepting Wilson's figures the total loss does not amount to a great extinction as he claims (p. 343). Alan McGowen also posted: >BTW, the term "mass extinction" is used also to refer to localized extinctions or extinctions confined to a limited group of taxa: anytime a group of lineages >come to an end in one (geological) episode you have a mass extinction. It is >not really a synonym for the largest few such extinction events in the fossil >record. So the arguments over whether there were "really" 5, 6 or some other >number are a bit off the mark: you have to specify the magnitude first. Think >of a frequency-magnitude distribution, like one for earthquakes. It should >come as no surprise that the big ones are rarer than the little ones. Well according to Raup (Extinction Bad Genes or Bad Luck, p65): "When a paleontologist is asked how many mass extinctions there have been, the invariable answer is five, ... -events known as the BIG FIVE." According to Wilson (p. 29) "The five mass extinctions occurred in this order ... . There have been a great many second- and third-order dips and rises, but these five are at the far end of the curve of violence, and they stand out" I agree that, regardless of terminology, there are also lesser extinction events and they are more common than the great extinctions. This is one reason I am inclined to doubt that humanity is currently causing a great extinction as opposed to some lesser extinction. Certainly humanity could cause a mass extinction (even perhaps end all life on earth). However the potential is not the act. I believe a claim that humanity is currently causing a mass extinction must be based on acts to date (and perhaps on reasonable near term projections) not on hypothetical acts in the far future. James B. Shearer ========================================================================= Date: 21 January 1994, 17:17:27 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction Events Len Evens posted: >It seems the me that the thought that the biosphere is going through >one of the few major extinctions in the history of the earth should >give anyone pause to think. ... I queried this. Len Evens adjusts his position to: >Let me modify my assertion. The thought that the biosphere is >going through an extinction which is _at_least_ as extensive as extinctions >which have occurred something like 60 times in the last 600,000,000 years >should give anyone pause to think. (I use the figures Mr. Shearer >used in one of his postings.) Actually you are misusing the figures I posted by converting an upper bound to a lower bound. I had observed that Wilson estimates a species kill of 10-25+% and that according to Raup 10% kills are expected every 2 million years, 25% kills every 10 million years. Also plugging Wilson's figures in Raup's curve underestimates the expected frequency of comparable events (probably by a significant amount) for the following reason. Raup's curve is derived from the fossil record, hence only applies to species widespread enough in time and space to appear in the fossil record. Wilson's estimates are for all species. Since common species are less vulnerable to extinction Wilson's figures should be adjusted downward before being plugged into Raup's curve. In this regard does anyone have estimates for the fraction of all species which appear in the fossil record? How about the higher taxa? Len Evens added: >Again, let me say what should be obvious to all. It is a quibble to >argue about whether we will have a 25% reduction is number of species >or a 60% reduction in the next 50 years. ... Somehow I suspect that if I had posted a 25% figure and you had corrected it to 60% you would feel the difference was significant. James B. Shearer ========================================================================= Date: 21 January 1994, 18:02:48 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Elementary Probability (was Extinction Events) I posted: >I found the Raup book more readable (and less political) than the Wilson >book. However the Raup book does contain two blatantly false assertions >which cause me to have some doubts about its reliability. On page 48 >Raup asserts that "Theoretically, casinos could make a profit by >offering an even-odds game as long as they put limits on how much >players bet." ... I added (in response to Len Evens): > It was in the middle of a chapter entitled "Gambler's Ruin >and Other Problems" which contains some elementary expository material >on random walks. ... A number of posters have defended Raup. Robert Grumbine: > Raup is being conservative here. In fact, as long as the house >starts with more money than the player, the house will break the player >_even at_ even-odds. This is the gambler's ruin problem, and is discussed >in most introductory probability classes. Carl Lydick: >Would've been nice if you'd mentioned that in the first place. When you're >dealing with an iterated fair game with 50/50 odds and a bankrupty constraint, >the player who starts with the bigger bank has a higher expected value. Raup was, based on the evidence so far in this thread, correct: A casino can expect >to make a profit on a game in which the odds don't favor the house, given that >the house has a larger bank than do the players. Mark O. Wilson: >I believe the theorey is that in the real world, gamblers who are winning >keep on gambling, those who loose it all, leave. > >Given this predisposition among gamblers, the house can come out ahead >even offering even money. You are all wrong. Briefly a (finite) series of fair bets yields a fair bet. In the particular case of a two player game where the players make a series of fair bets until one player or the other is wiped out a player's chance of prevailing is proportional to his initial stake. (Incidentally this has nothing to do with bet size as long as a player is not allowed to bet more than he has.) So if a player starts with 1 unit and the casino starts with 1 million units the casino is 1 million times as likely to win the iterated game as the player. However the game remains fair since when the player wins, he wins 1 million times as much as the casino does. Note also if all bets are unit size, from the point of view of the casino there is no difference between facing one player with a million units and a million players with one unit. The casino is playing against all the players combined and in the real world all the players combined have more capital than the casino. Finally in the same paragraph (Raup, Extinction Bad Luck or Bad Genes, p 48) makes the following statements: "Consider however, a high roller who enters our even-odds casino with assets equal to precisely half those of the house. If this gambler plays long enough or is allowed large enough bets, there is a fifty-fifty chance of his breaking the house." Are you all going to defend this statement as well? James B. Shearer ========================================================================= Date: 26 January 1994, 14:01:52 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction Events I posted: > I also believe the assumptions Wilson uses to derive species >losses from habitat losses are debatable. Andrew Taylor responded: >The theory used is about 16 years old (Wilson was one of the co-authors) >and well-tested. The assumptions seemed very conservative to me. The theory in question is that the equilibrium number of species a habitat can support is related to its area by an equation of the form N=c*A**z (where N is the number of species, A is the habitat area and z is an empirically derived constant. Often the rule of thumb that increasing area by a factor of 10 doubles the number of species is used. This corresponds to a value of z of about .3). According to Wilson (The Diversity of Life, p372) the rule of thumb is due to Darlington (1957, Wilson's paper was published in 1963). Wilson uses this relation to derive eventual species loss from habitat losses (ie for example losing 90% of the habitat will lead to the eventual loss of 50% of the species). Two debatable assumptions in doing this are: 1. The argument assumes the starting condition is in equilibrium. If it isn't the whole argument breaks down. If as Raup suggests rain forest area has fluctuated wildly in the last 50000 years this equilibrium assumption appears dubious. 2. The argument assumes that habitat destruction is not accompanied by fragmentation. Note by the nonlinear form of the area- species relation, many small islands can support more different species than a single big island of the same area. Again this assumption appears somewhat doubtful. James B. Shearer ========================================================================= Date: 26 January 1994, 14:06:00 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction Events Len Evens posted: >I think we both agree that Wilson asserts that if nothing is >done, the number of species becoming extinct will be greater than >or equal to 25% If not, why do you have the `+' after the `25'? >The exact quote from Wilson, which you yourself put in a previous posting is > >`Let me venture a guess. If the biodiversity crisis remains largely ignored >and natural habitats continue to decline, we will lose at least one >quarter of the earth's species.' > >I think that makes 25% a lower bound in Wilson's view. You are again misrepresenting my post. The actual "exact quote" from Wilson which I posted was "Finally, the question of central interest is how much of the world's biodiversity we can expect to carry with us out of the bottle- neck fifty or a hundred years hence. Let me venture a guess. If the biodiversity crisis remains largely ignored and natural habitats con- tinue to decline, we will lose at least one quarter of the earth's species. If we respond with the knowledge and technology already possessed, we may hold the loss to 10 percent. ..." I will let the reader judge which of us is more accurately presenting Wilson's views. I also posted: > Also plugging Wilson's figures in Raup's curve underestimates >the expected frequency of comparable events (probably by a significant >amount) for the following reason. Raup's curve is derived from the >fossil record, hence only applies to species widespread enough in >time and space to appear in the fossil record. Wilson's estimates >are for all species. Since common species are less vulnerable to >extinction Wilson's figures should be adjusted downward before being >plugged into Raup's curve. In this regard does anyone have estimates >for the fraction of all species which appear in the fossil record? Len Evens responded: >I'm not enough of a biologist to judge the validity of this argument. >Are you? Can someone better informed than either of us judge? The only biology used in this argument is that short lived species are under represented in the fossil record. Do you doubt this? Both Raup and Wilson make similar points: Raup, Extinction Bad Genes or Bad Luck, p. 108. "The estimate of ten species extinctions per year is based on life spans in the fossil record and thus applies to those species sufficiently abundant to be preserved and discovered. This generally means species that achieved a fairly wide geographical distribution, large populations, and a reasonably long duration. Missing are the many species which never got fully established. If these species could be added to the calculations, we would no doubt judge extinctions more common-but still rare from the viewpoint of the practicing field biologist." Wilson, The Diversity of Life, p. 218. "The orchids are not alone. They merely instruct us that, in addition to the species whose fossils suggest a longevity of 1 to 10 million years, there is a large hidden group of species that appear and disappear at a far higher rate. New species occupy small ranges on the average and are often started by small numbers of pioneers that land on island shores or distant mountain ridges. If extinction of such young vulnerable populations were high, the equivalent of infant mortality among organisms struggling in a harsh environment, a large percentage of species would die young with no record of their existence. The birth and death of most species may therefore lie behind a veil of artifact. Only the more widespread populations in or near bodies of water are fossilized with consistency for direct measurement. Behind the veil lie vast numbers of species that once lived in restricted habitats and are forever beyond direct access." James B. Shearer ========================================================================= Date: 27 January 1994, 18:03:10 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Impact Risks Robert Parson posted: >By coincidence, a recent issue of _Nature_ had an article about the risks >associated with asteroid collisions (one of those challenging cases, very >low probability but very high cost if it happens.) It includes the following >table: [_Nature_ _367_, p. 39, 6 Jan 1994)] > >Chances of dying from selected causes (USA) > > Cause of Death Chances > > Motor Vehicle Accident 1 in 100 > Murder 1 in 300 > Fire 1 in 800 > Asteroid/comet impact (lower limit) 1 in 3000 > Electrocution 1 in 5000 > Asteroid/comet impact 1 in 20,000 > Passenger air crash 1 in 20,000 > Flood 1 in 30,000 > Tornado 1 in 60,000 > Venomous bite or sting 1 in 100,000 > Asteroid/comet impact (upper limit) 1 in 250,000 > Fireworks accident 1 in 1 million > Botulism poisoning 1 in 3 million > Drinking water with EPA limit of TCE 1 in 10 million > >Of course many of these risks are not distributed homogeneously through >the population (Boulder vs. Detroit for murder, vichysoisse lovers for >Botulism, etc.) It should be noted that this paper ("Impacts on the Earth by asteroids and comets: assessing the hazard", Clark R. Chapman and David Morrison, Nature, vol 367, 6 Jan 1994, p33-40) contains a serious error. The authors compute a risk for an average person in the world and then use it without justification as the risk for an average person in the USA. Since the dominant contribution to the risk is starvation from a one year crop failure and since people in the USA are much less vulnerable to this risk than the world average this is ridiculous. Note also this paper is coming from NASA which is notorious for producing dishonest numbers. James B. Shearer ========================================================================= Date: 30 January 1994, 18:48:22 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: extinction events I posted: > 1. The argument assumes the starting condition is in >equilibrium. If it isn't the whole argument breaks down. If as Raup >suggests rain forest area has fluctuated wildly in the last 50000 years >this equilibrium assumption appears dubious. Don Baccus >Not necessarily. It depends upon the frequency of the fluctuation in >area, and the time needed to re-establish equilibrium. If, for >instance, there has been ten large-scale fluctuations in size which >happen over say, a few hundred years during that 50,000 year period, >you are left with potentially stable periods of thousands of years. This >might well be long enough to re-establish equilibrium. Equilibrium >may well be a more common state in such a system than change. Sure you can concoct scenarios where the system (absent humans) is in equilibrium. I can just as easily concoct scenarios where biodiversity is increasing or decreasing. To justify Wilson's calculation you must explain why your scenarios are consistent with the empirical data and mine are not. Don Baccus added: >It might well be impossible to determine if equilibrium exists today, >as separation of human-caused and "normal" extinctions seems like >a difficult problem. Yet, the rule-of-thumb quoted does seem to >fit island systems reasonably well. The rule-thumb-only only fits island systems which have been isolated long enough for equilibrium to be reached. Science is full of examples where empirical laws break down badly when attempts are made to apply them outside the realm of data on which they were derived. I also posted: > 2. The argument assumes that habitat destruction is not >accompanied by fragmentation. Note by the nonlinear form of the area- >species relation, many small islands can support more different species >than a single big island of the same area. Again this assumption >appears somewhat doubtful. Don Baccus replied >Why? Any data to support this doubt? After all, islands are known >for their relatively large number of endemic species. Since isolation >is thought to be the cause, and conversely in larger land areas free >communication is thought to minimize such reproductive isolation, the >assumption seems reasonable to me. Your assumption that organisms can freely move across land is wrong. If a patch of rain forest is left in the midst of cleared agricultural land many (most?) of the organisms in that patch will be reproductively isolated from the remaining rain forest. In fact studies have been done on how fast such patches lose species. James B. Shearer ========================================================================= Date: 30 January 1994, 19:27:43 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction Events I posted: > Is it obvious to you that the human impact on the biosphere is >causing more extinctions than going into an ice age would (as is >required for it to rank with the "big five" great extinctions)? It >is not obvious to me. Alan McGowen responded: >Incidently the # of extinctions associated with ice ages (+ humans) in the >Pleistocene is small compared to the "big five", and the extinction rate was >small compared to ongoing extinction rates. See Meyer's _The Sinking Ark_ and >see the article on Pleistocene extinctions in M. Nitecki, ed. _Extinctions_. >Rates of anthropogenic destruction of plant communities, the root of the >current extinction crisis, greatly exceed rates of vegetation change during >glacial advances, and the processes are quite different in impact on diversity: >glacial advances and the concomitant climate changes and biome shifts are >slow enough to permit new communities to form through natural dispersal >mechanisms and through the operation of natural selection on geographical >diversity within species. There is time for diversity to do its work and >for adjustment to occur. Anthropogenic habitat destruction, by contrast, >is typically a (locally) catastrophic event for most native species. You are assuming here that glacial advances and retreats are gradual. I was under the impression that the timescales involved are not accurately known and that some climatologists believe the transitions were quite rapid. Perhaps Michael Tobis could comment on this. In any case many species with small ranges will be trapped without escape paths as the climate changes (ie their habitat shrinks to nothing instead of moving). Also the total area of some habitat types will diminish causing losses due to area species effects. It is the case that most of these extinctions will not appear in the fossil record (because the species involved were too rare) however this is true of current extinctions as well. I remain unconvinced that the current loss of species is exceptional. I also said > It seems reasonable to believe that humanity is currently >causing an extinction event. To assert it is a great extinction seems >at best highly premature. Alan McGowen replied: >The rate of extinctions today greatly exceeds the average rate during most >geological extinctions, so the assertion has a plausible basis. What is the basis for this statement? According to Raup the fossil record is consistent with most past extinctions being almost instantaneous (see Raup, "Extinction Bad Genes or Bad Luck, p 79). He proposes that they could be due to meteorite impacts (chapter 10) which would imply very high extinction rates. Alan McGowen also said: >In short, this extinction crisis is more dangerous because human intelligence >is behind it. This would be true if humans were trying to do as much damage as possible to the biosphere. It seems more likely that humans will use their intelligence to attempt to mitigate the damage which would make this crisis less dangerous. James B. Shearer ========================================================================= Date: 30 January 1994, 20:25:23 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction Events Alan McGowen posted: >E.g. focusing on tropical forests, it seems quite possible that these >habitats could shrink to 10% of their original extent, and remain so long >enough (a century or more) for equilibrium to be approached (near enough) >in most taxa, resulting in a loss of around 50% in those habitats, which >would probably be at least 25% of the Earth's diversity. ... You suggest here that a century is long enough to lose most of the excess species. However according to Norman Myers (The Sinking Ark, p.224) "An island of size 7500 km**2 has typically lost 51% of its excess species during the past 10000 years ..." (referring to islands isolated from the mainland 10000 years ago). This implies a period much longer than a century may be needed. (Myers also indicates that the larger the island the slower the approach to equilibrium. Islands of size less than 250 km**2 have reached equilibrium in 10000 years.) Alan McGowen also posted: >In short, there is no good reason to expect the losses to be capped at >25% if nothing is done. The optimistic estimate that no more than 10% >might be lost should be taken as Wilson's guess of the best minimum we >could hope for if current trends were averted to the greatest extent >he thinks possible, and 25% as the the *minimum* loss which can be *expected* >as a result of current trends, should these continue for a few more decades >-- which they seem rather likely to do. Shearer's idea that 25% is some >sort of worst-case maximum has no foundation either in biology or in Wilson's >text, if read with understanding. I have never stated that I believe 25% is a worst-case maxiumum nor quoted Wilson to that effect (I was careful to say 25+ not 25). My dispute with Evens was whether Wilson's best case was 10% loss (as I contended) or 25+% loss (as Evens contended). Obviously the worst case is 100% (or close to it). James B. Shearer ========================================================================= Date: 8 February 1994, 22:36:56 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: extinction events I said: > Sure you can concoct scenarios where the system (absent >humans) is in equilibrium. I can just as easily concoct scenarios >where biodiversity is increasing or decreasing. To justify Wilson's >calculation you must explain why your scenarios are consistent with >the empirical data and mine are not. Don Baccus replied: >You were the one who claimed the scenario outlined by Wilson was doubtful. >I simply proposed an example which would fit the scenario. Why should >I have to explain why my scenario is consistent with Wilson's when you >claim his conclusions are "doubtful" without any discussion of the >empirical data whatsoever? You are attempting to shoot down his >argument by use of the (non-technical) term "doubtful" without any >justification. I have to justify my objection to your unjustified >statement? ****pucky. My point was that your claim was made without >justification. I appreciate your strengthening of my claim. Wilson's calculation depends on the system absent humans being in equilibrium. He presents no evidence for this being the case and neither do you. Absent such evidence his argument is incomplete, hence subject to doubt or uncertain, hence doubtful. Doubtful does not mean the same thing as false. I said: > The rule-thumb-only only fits island systems which have >been isolated long enough for equilibrium to be reached. > Science is full of examples where empirical laws break down >badly when attempts are made to apply them outside the realm of data >on which they were derived. Don Baccus responded >And, of course, I was pointing out that you're "doubtful" statement >was made without any justification of your presumption that equilibrium >has NOT been reached. Wilson is the one making the calculation which depends on equilibrium having been reached so it is up to him to justify it. Don Baccus posted: >Why? Any data to support this doubt? After all, islands are known >for their relatively large number of endemic species. Since isolation >is thought to be the cause, and conversely in larger land areas free >communication is thought to minimize such reproductive isolation, the >assumption seems reasonable to me. I replied: > Your assumption that organisms can freely move across land is >wrong. If a patch of rain forest is left in the midst of cleared >agricultural land many (most?) of the organisms in that patch will be >reproductively isolated from the remaining rain forest. In fact >studies have been done on how fast such patches lose species. Don Baccus replied: >Yes, such isolated areas act very mucn like islands. The mountain >ranges of the Great Basin are an excellent example of this. > >You originally were discussing the fragmentation of habitat caused >by destruction. You now say that my assumption that organisms can >move freely is incorrect. However, the assumption underlying your >original statement was that the habitat was not yet fragmented, >so my statement was fine in the context of your original statement. >Your rebuttal above gives an example where such fragmentation has happened. >In the context of this different example my statement admittedly does >not make sense. It is not the same scenario as that painted in your >original statement, however. My original statement which you apparently did not read carefully was: > 2. The argument assumes that habitat destruction is not >accompanied by fragmentation. Note by the nonlinear form of the area- >species relation, many small islands can support more different species >than a single big island of the same area. Again this assumption >appears somewhat doubtful. For example if in the process of destroying 90% of a single unified habitat it is also fragmented into 10 separate habitats each containing 1% of the area of the single habitat, application of the area species relation predicts an eventual gain in biodiversity rather than a 50% loss. James B. Shearer ========================================================================= Date: 9 February 1994, 00:26:32 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Elementary probability Alan McGowen posts: >If people would read the chapter in the Raup book it would become apparant >how to settle this increasingly frivolous argument. Raup, in a popular >book (i.e. assume minimal math of the reader) is trying to show that every >species can be expected to become extinct sooner or later, a true statement. >He wants to show this with minimal ecological assumptions as well as minimal >mathematics. This is a pedagogic problem, not a controversial scientific one. To review, the statement to which I objected was "Theoretically, casinos could make a profit by offering an even-odds game as long as they put limits on how much players bet." (Raup, "Extinction Bad Genes or Bad Luck", p.48). Anyone who understands elementary probability should see that this statement is flagrantly false. Unfortunately it is now apparent that a large number of posters to this group do not understand elementary probability. I understand that popular books may sketch arguments and omit details. I do not believe this justifys false statements like Raup's. He is either being extremely careless or displaying a fundamental misunderstanding of elementary probability. Alan McGowen also posted: >It would be especially nice to have a way of showing, again using only >high-school math, not just that extinction is inevitable given infinite >time, but that it is inevitable in geological time -- which the fossil >record demonstrates clearly enough to be true. If heads were put to that >problem some public educational benefit might actually result :-). I assume by extinction you don't mean "leaves no living descendants" but instead mean "leaves no living descendants with which it could interbreed". This second statement appears more or less equivalent to the claim that reproductively isolated populations will eventually become separate species. I believe it would be easy enough to concoct models which would predict this due to the accumulation of many small changes over time. James B. Shearer ========================================================================= Date: 9 February 1994, 21:04:43 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction events I posted: > Wilson uses this relation [a power law for the species-area >relation] to derive eventual species loss from >habitat losses (ie for example losing 90% of the habitat will lead to >the eventual loss of 50% of the species). Two debatable assumptions in >doing this are: > 1. The argument assumes the starting condition is in >equilibrium. If it isn't the whole argument breaks down. If as Raup >suggests rain forest area has fluctuated wildly in the last 50000 years >this equilibrium assumption appears dubious. Alan McGowen replied: >The general applicability of power law relations to diversity-area is the >result of literally hundreds of field studies of many different kinds. It >is not hanging by one theoretical thread as Shearer seems to think. It can >be regarded as an observed fact. ... I am not questioning the diversity-area relation. I am questioning whether it makes sense to use it to predict species loss from habitat loss if the starting condition is not in equilibrium. Alan McGowen posted: >Larger fragments will decay more slowly, but deforestation leaves mostly >smaller fragments. To calibrate expections, consider Barrow Colorado, an >island of 15 km^2 formed by the Panama Canal. According to Diamond, 1984 >of ~108 breeding species of bird formerly recorded, ~45 had disappreared >at the time of the article. But Diamond cites a study which suggests that >losses may have been greater, since detailed studies of avifauna did not >begin until well after the island formed. There is abundant evidence to >suggest that if tropical primary forest were reduced to a likely highly >fragmented 10% of its current extent, losses would be substantial within >the first century or few among those species that had not disappeared >already from loss of their total habitat; it is thought that at least >half the species destroyed would be gone immediately for that reason. Numbers for Barro Colorado seem to vary. Wilson says 13 out of 108 in 50 years ("The Diversity of Life", p279). Paul and Anne Ehrlich 48 out of 208 ("Extinction", p223). In any case many of the extinctions were not due to the diversity area effect but instead due to habitat changes as forest was allowed to regrow in cleared areas. I agree however that species such as birds will be lost fairly quickly from small fragments. (I would suspect that what small means would vary with the amount of area required to support an individual of a species. In other words beatles would be lost slower than birds. Is this correct?) However if small fragments dominate the end condition then the assumption in Wilson's calculation that fragmentation is not occurring is incorrect. Btw Wilson refers to loss of 90% of the original rain forest habitat. Since 50% of it is already gone (some of it long ago) this would be 80% of the current habitat. Alan McGowen also posted: >Shearer's worry about extinctions which do not show up in the fossil record >but do in the current extinction is easily compensated for. Simply confine >comparison to extinction rates in groups that are well represented in the >fossil record and form the tip of the biodiversity iceberg. When that is done, >current extinction rates in many groups will still be found to exceed average >rates during the Pleistocene extinction and many earlier extinctions. E.g. >Nowhere near 50% of all tropical mammal and bird species became extinct during >tens of millennia in the Pleistocene extinction, but that is a very real >possibility just within the next century or few of the ongoing anthropogenic >extinction. So we don't need to know anything about the extinctions of >Pleistocene mites to see that the current extinction event threatens to be >much bigger than the Pleistocene extinction. I agree that one can attempt to compensate for this effect. I doubt it is all that easy. I do not believe that it will suffice to just consider birds since there will still be a bias unless you are asserting all bird species will appear in the fossil record (and be recognized as distinct species). In this regard how many bird species are recognized as living 5, 10, 20 and 50 million years ago as opposed to today? Alan McGowen >The high current rate of extinction compared to average rates in most >geological mass extinctions does present a risk that this extinction >could become a "great" one, if it continues. Shearer may think >it "highly premature" to judge until all the damage has been done, but I >suspect that most people will have a little less difficulty grasping the >meaning of the conditional, and seeing that it would be wise to try to >avert it. There was no conditional in the original claim by Evens that we are currently undergoing a great extinction (Wilson's book makes the same claim) which I queried starting this thread. If you wish to say this could be a great extinction I have no objection. There are many possible futures. I do object to your saying the current extinction rate is higher than in most past mass extinctions since I do not believe the rates in most past mass extinctions are known. Alan McGowen also posted (regarding a speculation of Raup that most past mass extinctions were caused by meteorite impacts): >For contrasting views, see Stephan K. Donovan, ed. _Mass Extinctions: Processes >and Evidence_, 1989 Columbia University Press, New York. One paper "Changing >paleontological views on mass extinction phenomena" by Antoni Hoffmann >summarizes the state of evidence as follows: "Suffice it to note here that >no evidence has thus far been presented that would firmly link the >pre-Cretaceous-Tertiary extinctions with bolide impacts; and the impact >causation of the Cretaceous-Tertiary and Eocene-Oligocene extinctions is >also highly contentious. The question of extinction periodicity, moreover, >is no less controversial." Other authors in the book rain about equally >hard on the Nemesis parade. High extinction rates confined to brief periods >of time (as opposed to a more gradually building and declining extinction) >are explicitly dismissed as inconsistent with the evidence in the paper on >the end-Permian mass extinction. > >Thus, most paleontologists are apparantly not convinced that mass extinctions >normally occur as short, sharp shocks with enormously high rates of extinction >for very brief periods. The present extinction is not known to be typical in >that regard, contrary to what Shearer implied. My claim is that it is not known that current extinction rates are higher than in past mass extinctions because it is not known what extinction rates in past mass extinctions were. Regarding the K-T extinction is it not the case that 20 years ago many paleontologists would have claimed the evidence showed this was a gradual event hence could not have been caused by a meteorite impact? James B. Shearer ========================================================================= Date: 27 February 1994, 10:30:44 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Global warming UN-FAQ Robert Grumbine posted: >Deterministic -- Subsequent states are _determined_ by present conditions. > The climate system is deterministic. This does not conflict with it being > chaotic. See also chaotic. Quantum mechanics says real systems are not deterministic. Robert Grumbine also posted: >Chaotic -- A system in which: 1) Small changes in initial conditions can > lead to large changes in state in the future (the seagull effect) 2) > Is nonetheless governed by deterministic laws (i.e., is not random) > 3) In spite of 1, has bounded behavior (i.e., chaotic does not mean > 'anything can happen') See also nonlinear, deterministic, seagull effect. This definition needs work. The system dy/dx=y has property 1) however few people would say it is chaotic. James B. Shearer ========================================================================= Date: 3 March 1994, 12:10:07 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Re: James Bay Michael Tobis asks for comments on the proposed James Bay hydro project from an environmental perspective. I would like to see comments from an economic perspective. I have the vague impression that James Bay may be a grandiose boondoggle (which governments too often undertake). Regarding environmental effects, I see no particular justification for just comparing to coal. Why not compare to nuclear plants of the same capacity as well. James B. Shearer ========================================================================= Date: 3 March 1994, 16:03:13 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Club of Rome Regarding the Club of Rome world model and its predictions, I have seen it claimed that the Club of Rome did not manage to solve their stated model correctly and that a mathematically correct solution shows wealth going to infinity (instead of rising then crashing). Does anyone know if this is true? James B. Shearer ========================================================================= Date: 3 March 1994, 16:11:44 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Cost of new nuclear capacity (was IFR will solve...) Andy Holland posted: >New US capacity is high fuel cost, lower O&M, lower capital compared >to nuclear. It might cost $0.04 /kw-hr, but you can recover it >alot simpler, with much less risk, than a $0.015 /Kw-Hr nuke. You appear to be claiming that new nuclear plants could be built to deliver power at $.015 /Kwh. This implies a capital cost of $2000/Kw or less. I find it difficult to believe that this is realistic. Do you have some substantiation for this claim? I am under the impression that new nuclear plants are currently not economically competitive with new coal or natural gas plants (in the US) under any reasonable accounting system (which is why they are not being built). Do you have figures which show otherwise? James B. Shearer ========================================================================= Date: 13 March 1994, 19:13:08 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Re: Quebec hydro Michael Tobis posted > ... What is >interesting is that the usual defenders of anything anti-environmental, >the sort of folks who will show up to say "dioxin is not only harmless, >it is GOOD FOR YOU, I drink a cup every morning etc etc." at the least >provocation are going to be silent on this one because of their ideological >commitment to having any government instigated project fail. ... This may not be addressed to me (since I don't actually believe dioxin is good for you) but I will reply to it anyway. You asked for comments on Quebec hydro projects from an environmental perspective. Since I largely reject the environmentalist's worldview (in favor of the economist's worldview) it makes no sense for me to defend Quebec hydro on environmental grounds. In my worldview if new Quebec hydro power will cost .08 $/kwh while new coal power will cost .05 $/kwh new Quebec hydro plants are a waste of money and should not be built. I am suspicious of government and am unwilling to accept on faith that Quebec hydro "knows what they're doing". The TVA thought it knew what it was doing. This does not mean I have an ideological commitment to seeing all government projects fail. I am quite happy with the interstate highway system for example (as are I imagine most anti-environmentalists). I am reluctant to analyse Quebec hydro from an environmental perspective even as an intellectual exercise for several reasons. 1. By so doing I might lend credibility to the environmen- talist worldview (many environmentalists are unwilling to debate cost benefit analyses for similar reasons). 2. I am not confident I understand the environmentalist worldview well enough to do so. In this regard there is the additional complication that your idea of an environmental perspective appears to differ from that of most environmentalists. Most environmentalists appear to believe all largescale modification of the natural environment is wrong and should be opposed which doesn't leave much of a case for new Quebec hydro projects. Your worldview appears to be some strange mishmash of the economist's and environmentalist's worldview of which as far as I can tell you are the only proponent. Why do you expect everyone else to analyse Quebec hydro on your terms? 3. Evaluating Quebec hydro requires information which is not readily available to laymen (perhaps you should be asking your questions in a different newsgroup). In this regard it is a bit amazing to me that you can vigorously support new Quebec hydro projects while knowing practically nothing about them. Why do you expect other people to do the research required to sensibly defend your pet projects? James B. Shearer ========================================================================= Date: 13 March 1994, 20:30:12 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Re: bandwidth pollution (was diesel emissions) Len Evens asks: >I am fairly certain that it is illegal to use the internet for >commercial purposes, but I don't know to whom one can complain. >Does anyone have a suggestion about what to do about this particular >advertisement. The only thing that occurs to me is that if the >claims made in the ad are not correct, the poster might be >subject to prosecution for mail fraud, particularly if the mails >were used to further the project. However, there ought to be >a more convincing and direct way to stop this sort of thing. Well if you feel strongly you could call him up on the 800 number he was thoughtful enough to provide and give him a lecture. James B. Shearer ========================================================================= Date: 16 March 1994, 17:32:18 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Re: Quebec hydro Dianne Murray posted: >ANSWERS to James Bay QUESTIONS > >Part 1: How many projects, How much land flooded, How much energy generated > >Proposed* and Existing Hydro Projects in the Hudson Bay Bioregion > >Project Land flooded (km2) Energy generated (MW) >----------------------------------------------------------------------------- > >PROPOSED > >Great Whale 956 3,063 > >NBR 3,818 8,400 > >New Moose River 30 1,890 >Basin projects >_____________________________________________________________________________ > >EXISTING: >La Grande 10,746 15,530 > >Churchill-Nelson 600 3,300 > >Moose River Basin unknown 1,033 > >----------------------------------------------------------------------------- >*Does not include the 26 dams planned for the Severn River region, >the Mattagami River Complex, nor the proposed projects in northern Manitoba The power figures given appear to be capacity or peak rate figures. It is also necessary to know the average rate over a year. How much will this vary year to year and seasonally? I would also be interested in knowing capital costs, operating costs, transmission costs and expected sales prices and markets for new Quebec hydro power. James B. Shearer ========================================================================= Date: 17 March 1994, 17:59:04 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Quebec hydro Dianne Murray responds to my reply to Michael Tobis: I said: >Since I largely reject the environmentalist's worldview (in favor of the >economist's worldview) it makes no sense for me to defend Quebec hydro >on environmental grounds. Dianne Murray responded: >Well, the conomy is based, ultimately on inputs from the environment, >so this strikes me as a false dichotomy. Are you asserting that the worldviews of economists and environmentalists are in fact compatible? The general attitude of economists and enviromentalists toward: 1. Largescale alteration of the natural environment. 2. Value of other species. 3. Private property rights. 4. Cost benefit analysis. 5. Discounting the future. 6. Free markets. etc. is quite different. I said: > In my worldview if new Quebec hydro power >will cost .08 $/kwh while new coal power will cost .05 $/kwh new Quebec >hydro plants are a waste of money and should not be built. Dianne Murray replied: >Even iuf you do a straight cash calculation, long-range costs must be >factored in. These would include increased taxes form taking Cree >off subsistance and putting them on welfare. There are virtually no >jobs up there. Further, there will be increased medical costs of >changing these people's diets (see earlier post to Michael Tobis re: >Cost/benefits). Costs must be factored in only if they are significant. (Climate models need not include the warming effects of starlight.) Also I believe the costs to the Cree are a red herring in that if the Cree did not exist the opponents of Quebec hydro would just come up with other reasons for opposing the projects. (In fairness I suspect this is true of Tobis and global warming as well. I.E. if global warming was shown to be a false alarm, Tobis would still support Quebec hydro projects.) I said: > 3. Evaluating Quebec hydro requires information which is not >readily available to laymen (perhaps you should be asking your questions >in a different newsgroup). Dianne Murray replied: >This is *sci.environment*. It may not be perfect but I can't think of >a better place on the Net to discuss it. What would you suggest? I am not familiar with every part of the Net. Science.energy or sci.econ might be better places to find Quebec hydro supporters. I said: > In this regard it is a bit amazing to me >that you can vigorously support new Quebec hydro projects while knowing >practically nothing about them. Why do you expect other people to do >the research required to sensibly defend your pet projects? Dianne Murray replied: >Well, I think that Michael asked a question that is very important. >With regard to greenhouse gases. But I also think that some of the >assumptions he makes (that there have to be real economic benefits >or they wouldn't build it) are politically naive. > >He had said initially that he had not made up his mind about the >issue, and wanted to know more about the comparison between coal-fired >generators, and these particular projects. I'm not sure it's a pet >project for him so much as a real curiosity. What he said (as quoted by Dianne Murray) was: >I have *not made up my mind* on the question. I have only said that I am >inclined to support it *pending a rational argument* that I should not. >Surely, if the project is as awful as the respondents have been claiming, >such a rational argument must exist! It is apparent to anyone who follows this group that Tobis has a bee in his bonnet on the subject of Quebec hydro. Despite the fact that he is unable to produce a rational argument in favor of Quebec hydro he demands opponents convince him it is a bad idea. James B. Shearer ========================================================================= Date: 18 March 1994, 17:21:23 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Quebec hydro Bo Curry posts (in response to my claim that environmentalists and economists see the world in incompatible ways): >To the extent to which the "worldviews" of economists and environmentalists >are incompatible, we need new economists or new environmentalists. I would opt for new environmentalists myself. Bo Curry added: >In my experience, the views of economists generally quite diverse, >and not so easy to characterize. Or are you only counting economists >of one particular school? I am referring to mainstream economists of the type who win the Nobel prize in economics. For further support of my position I will quote Lester Thurow (Head to Head, 1992, p.220) who is somewhat out of the economics mainstream: "In principle, environmentalism is a place where the professional economist and the professional environmetalists should be working together, yet over the past twenty-five years no two fighting cocks have ever disliked each other more. Even when they start out sympathetic to each other's aims they can barely sit in the same room. ..." I said: : In my worldview if new Quebec hydro power :will cost .08 $/kwh while new coal power will cost .05 $/kwh new Quebec :hydro plants are a waste of money and should not be built. Bo Curry replied: >Ah. So when you write "economist", we should read "monetarist"? >That clarifies your postings considerably. Is this intended to be a joke or do you really not know what a "monetarist" is? I said: : Costs must be factored in only if they are significant. :(Climate models need not include the warming effects of starlight.) :Also I believe the costs to the Cree are a red herring in that if the :Cree did not exist the opponents of Quebec hydro would just come up :with other reasons for opposing the projects. Bo Curry responds: >This might be the way *you* approach conflicting evidence, but it >is grossly unfair of you to attribute such an idiotic way of >making choices to everybody else. In particular ... I also said: :(In fairness I suspect :this is true of Tobis and global warming as well. I.E. if global :warming was shown to be a false alarm, Tobis would still support Quebec :hydro projects.) and Bo Curry replies: >I think this is simply nonsense. Well if Dianne Murray posts that she would support Quebec hydro were it not for its effects on the Cree or if Michael Tobis posts that he would oppose Quebec hydro were it not for its effects on global warming I will reconsider my position. Failing that I will continue to believe both are employing what Tobis himself has called "lawyer's logic". James B. Shearer ========================================================================= Date: 18 March 1994, 18:23:29 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Quebec hydro I said (in reply to Michael Tobis): |>You asked for |>comments on Quebec hydro projects from an environmental perspective. |>Since I largely reject the environmentalist's worldview (in favor of the |>economist's worldview) it makes no sense for me to defend Quebec hydro |>on environmental grounds. In my worldview if new Quebec hydro power |>will cost .08 $/kwh while new coal power will cost .05 $/kwh new Quebec |>hydro plants are a waste of money and should not be built. Michael Tobis responded: >This is fair enough if external costs are figured in. On the assumption that >the technologies are currently competitive, (based on the fact that Quebec >currently exports hydroelectricity to the northeast US) and that the external >costs are NOT figured in, I conclude that a comparison of the external costs >will indicate whether the plan is sensible. Michael Tobis also stated: >I simplify the cost-benefit analysis by noting that electricity is fungible >and hence the benefits of this project are comparable to similar coal >generation, and since the technologies are currently competitive, the >difference in costs will be dominated by externalities, i.e., environmental >costs. > >I propose that a one-for-one comparison with the most environmentally >damaging technology in current use is a sensible question to ask in deciding >whether such a project should be implemeted. > >You seem to agree with many of my activist respondents that it is not a >sensible question, but neither you nor they has explained why. Michael Tobis also stated: >I consider it demonstrated that the external costs to power generation >dominate the cost-benefit picture. > >Since the benefits of hydro and coal are about the same, this ought to >permit participation in this discussion by both those who regard external >costs as relatively small and those who regard them as dominant to discuss >the technical question of which method has the larger external costs! I would suggest you obtain and read some elementary economics textbooks. Then maybe you could discuss this sensibly. You are ignoring the following considerations. 1. The fact that both coal and hydro are currently used to generate power does not mean every coal and hydro plant current or proposed has the same cost. The cost of hydro depends on the site. Most of the best sites have already been used. The remaining sites may be too expensive to compete. 2. Power generation is very capital intensive. New plants are rarely built to replace existing plants because for this to be sensible requires that the capital cost and operating cost of the new plant be less than the operating cost of the old plant. This means a new hydro plant is likely to displace some other new plant not the most environ- mentally damaging plant in current use. It should also be noted that coal plants are comparatively rare in the American northeast. 3. I don't know exactly what you mean by "electricity is fungible" however it is certainly not the case that electricity in the middle of nowhere in northern Quebec is interchangeable with electricity in New York City. The cost of transmission is not negligible especially given the current opposition to any new high voltage lines. 4. I don't see what the fact that Quebec exports hydro electricity to the northeast proves. Because of point 2) once a plant has been built it generally makes sense to operate it and sell the power for what you can get. This does not mean it makes sense to build more plants. US utilities are still running their nuclear plants. By the way I would like some numbers on the amount and price of Quebec electricity sales to the northeast. Michael Tobis also posted (regarding my refusal to concede that Quebec hydro knows what it is doing): >In any case, if they don't know what they are doing, wouldn't your world >view tend to let the Darwinian forces of the marketplace take care of >their mistakes? I thought the point at issue was whether these projects were a good idea not whether Quebec hydro should be allowed to build them. I don't really care if Quebec hydro squanders billions, it's not my money (at least as long as they don't talk Con Ed into helping). In any case these projects may make economic sense, I just won't assume this on faith. Michael Tobis also said: >Persons who oppose this sort of project on environmental grounds therefore >have to demonstrate not that the impact is large, but that it is larger than >the impact of the major (currently plausible) alternative, which is to >say, spewing of enormous quantities of carbon into the air. Let us look at some data. The following table gives the net electricity generation at US electric utilities by energy source in 1975 and 1990 in billions of kilowatt hours: year coal oil gas nuclear hydro other total 1975 853 289 300 173 300 3 1918 1990 1557 117 263 577 280 11 2805 Looking at these numbers I don't see how anyone can believe hydro is a plausible alternative to coal. James B. Shearer ========================================================================= Date: 21 March 1994, 17:17:58 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Quebec hydro Michael Tobis said (about economists vrs environmentalists): >The first order analyses are indeed different on all these questions, as >to first order the environmentalist neglects the economy and the economist >neglects the environment. In the real word we have to reconcile these >analyses. To the extent that they differ in any particular circumstance, >the first order analysis fails, and a combined ecolonomic analysis is >required. (Interestingly, etymologically "ecology" and "economy" are the >same word!) > >That is, to the extent that both approaches are rational (and that the >world yields to rational analysis), incompatible conclusions imply that >some of the factors that have been neglected by at least one of the analyses >are significant. Which is to agree with Bo Curry, that better analyses >at least, if not better practitioners, are needed. This is simply not true. Incompatible conclusions may indicate incompatible values, goals or objectives. If we are in New Orleans and you wish to go to Denver and I wish to go to New York a better analysis will not help us decide on a route. James B. Shearer ========================================================================= Date: 27 March 1994, 21:25:09 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction rates Alan McGowen posted: >Since this thread is in both talk.environment and sci.environment, it would >be more useful to "show the work". The extinction rate E = N/L, where N >is the number of species and L is average lifespan. N is almost certainly >> 10 million, probably 100 million is the best current estimate. L (from >the fossil record) is 2-3 million years for vertebrates and ~10 million for marine inverts. Taking ~50 million species and ~5 million years for a "typical" species, E = 50 million/5 million yr = 10/year -- that's the order of magnitude >we are talking about. Since the number of species has been slowly increasing >through the Phanerozoic, the (geological) average speciation rate must be >slightly greater than that. These normal extinctions and speciations would >most often happen among small, obscure organisms with tiny ranges and short >generation times -- the little guys who run most of the planet's life >processes. They would be very hard to observe. And the events may not be >uniformly spread out through time; their distribution may well be clumpier, >and correlated to the natural spectrum of ecological changes. The fossil record is an extremely biased record of species. Long lived species are clearly more likely to appear in the fossil record. For this reason it is absurd to apply a average lifetime for species appearing in the fossil record to all current species as you are doing. I would bet an appropriate average lifetime is less by a factor of at least 100. Suppose for example current species can be divided into five classes (with 10 million species each) with lifetimes of 10 million, 1 million, 100 thousand, 10 thousand and 1 thousand years. The appropriate overall average lifetime is then 4500 years (based on the harmonic mean since we are interested in the average extinction rate and extinction rates are the inverse of lifetimes) and the expected number of species extinctions per year is 11111. James B. Shearer ========================================================================= Date: 28 March 1994, 13:43:59 EST From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: extinction rates Andrew Taylor posted: >I don't know what you mean by instaneous extinction rate as extinctions >are discrete. The fossil record certainly has sufficent resolution for >example to allow estimates to be made of the duration of the Permian >extinction and hence the average rate at which it occurred. See the >review article on the Permian extinction by Erwin in Nature Jan. '94. This is misleading. Such estimates are upper bounds on the duration. Mass extinctions appear to be instantaneous and the estimates are based on the fact that events lasting x million years would not appear to be instantaneous with people arguing about what x is. The actual words of the Nature article you mention are: "... There is however little support for claims that the mass extinction occurred over eight million years(8), but it is unclear whether the extinction lasted two million years, 1 million years or even less." It should also be noted that there is extreme bias among many paleontologists against catastrophic explanations of events in the fossil record. This showed up for instance in the initial reaction to the impact hypothesis for the KT extinction where totally unjustifed claims were made that the fossil record showed the KT extinction was a prolonged event. James B. Shearer ========================================================================= Date: 3 April 1994, 18:57:04 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Quebec hydro I posted: |> Let us look at some data. The following table gives the net |> electricity generation at US electric utilities by energy source in |> 1975 and 1990 in billions of kilowatt hours: |> year coal oil gas nuclear hydro other total |> 1975 853 289 300 173 300 3 1918 |> 1990 1557 117 263 577 280 11 2805 |> Looking at these numbers I don't see how anyone can believe |> hydro is a plausible alternative to coal. Michael Tobis responded. >You didn't include the figures for Canada, or the import numbers. I don't have figures for Canada. Net imports were negligible in these years 6 billion kwh in 1975, 2 billion kwh in 1990 (converted from btu assuming 10000 btu per kwh). Net imports were larger in other years as much as 40 billion kwh in 1985. Michael Tobis added: >My point to you is that Canadian hydro could provide a good chunk of that >energy and your figures say nothing about this. How about some numbers? How many billion kwh do you believe Canadian hydro could provide to the US per year (and at what price)? Michael Tobis also posted: >I note also that your figures flatly contradict the assertions of >environmentalists that energy demand has not grown significantly in the last >two decades. 1. The figures are for electricity not energy. 2. The figures are for production not demand. 3. Environmentalists lie a lot. (However they are not the only ones.) James B. Shearer ========================================================================= Date: 3 April 1994, 19:29:48 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Extinction rates Leonard Evens posted: >From casual reading, I thought that no one seriously thought the >Permian extinction was instantaneous in the sense of a >asteroid collision. Paleontologists might be biased, but they >might also be right in that instance. What evidence do you >have for an instantaneous explanation of the Permian extinction? >What do you consider instantaneous anyway? Instantaneous=without duration. Obviously I do not believe the Permian extinction was actually instantaneous, I am just claiming whatever duration it had is indistinguishable from 0 in the fossil record (as presently understood). I do not know the cause of the Permian extinction. However given that the KT extinction is now plausibly believed to be a catastrophic event I see no reason to exclude catastrophic explanations for the other mass extinctions. James B. Shearer ========================================================================= Date: 4 April 1994, 11:06:37 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: human effect on NPP Alan McGowen posts: >Rather, what we dark greens want is something more like "equal opportunity" >-- a fair chance for all species. > >That is not the case today. The current human population coopts some 40% of >terrestrial NPP -- the "power supply" for millions of other species and for >the ecosystem functions they bring about. That number is bound to rise >even further as human numbers increase and as economic growth increases >consumption of natural resources. You are omitting what would appear to be a relevant figure, the human impact on total terrestrial NPP. Is this known? James B. Shearer ========================================================================= Date: 10 April 1994, 19:19:38 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: extinction rates I posted (in reply to a calculation of extinction rates by Alan McGowen based on an average species lifetime of 5 million years). > The fossil record is an extremely biased record of species. >Long lived species are clearly more likely to appear in the fossil >record. For this reason it is absurd to apply a average lifetime >for species appearing in the fossil record to all current species as >you are doing. I would bet an appropriate average lifetime is less by a >factor of at least 100. > Suppose for example current species can be divided into five >classes (with 10 million species each) with lifetimes of 10 million, >1 million, 100 thousand, 10 thousand and 1 thousand years. The >appropriate overall average lifetime is then 4500 years (based on the >harmonic mean since we are interested in the average extinction rate >and extinction rates are the inverse of lifetimes) and the expected >number of species extinctions per year is 11111. Alan McGowen responded: >Certainly if one postulates a large number of species with very short >lifespans the consequence would be a high rate of normal extinctions. >[Of course, it would be nice to have a little evidence for such a >postulate. It needn't be fossil evidence; molecular evidence for >widespread extreme youth would be fine. :-) ] You on the other hand are postulating that there are not a large number of species with short lifespans. Since you are the one who purported to calculate a normal extinction rate I would say the burden of proof is on you. As to whose postulate is more plausible let me quote Wilson again (Diversity of Life, p 219). "The orchids are not alone. They merely instruct us that, in addition to the species whose fossils suggest a longevity of 1 to 10 million years, there is a large hidden group of species that appear and disappear at a far higher rate. New species occupy small ranges on the average and are often started by small numbers of pioneers that land on island shores or distant mountain ridges. If extinction of such young vulnerable populations were high, the equivalent of infant mortality among organisms struggling in a harsh environment, a large percentage of species would die young with no record of their existence. The birth and death of most species may therefore lie behind a veil of artifact. Only the more widespread populations in or near bodies of water are fossilized with consistency for direct measurement. Behind the veil lie vast numbers of species that once lived in restricted habitats and are forever beyond direct access." James B. Shearer ========================================================================= Date: 2 May 1994, 19:27:09 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Re: Economics (was Feeding 15 billion people) Michael Tobis posted: >The efficiencies of the free market are based on a situation in which labor >is in short supply. ... This is nonsense. The efficiency of the free market does not depend on the supply of labor or any other resource. If a resource is scarce its free market price is high discouraging use, if a resource is abundant its free market price is low encouraging use. Michael Tobis also posted: >As for the more advanced economies, artificial scarcity prevails. Thus, while >for example, we could in principle get power from nuclear plants to >externally powered vehicles, this would require an enormous up-front >expenditure and some level of mutual trust among the citizens and between >the citizenry and its government. (Can you say "read my lips... new taxes"?) > >But under the current circumstance of media-propagated suspicion and >hostility people would much rather stay with the devil they know: some will >oppose the nuclear power and others will oppose the electric cars, and >almost all will oppose the collective action required. The result is that >while we could easily have sustainable (non carbon-spewing, non energy >wasting, reasonable momentum) mechanical transportation technically, it is >socially unachievable. The same can be said for a civic architecture which >doesn't demand as much travel. Why should society spend a large amount of money in order to obtain an inferior transportation system? People do tend to be suspicious and hostile when presented with proposals to make them worse off. This is a good thing. Btw you appear to be using "demand" as an euphemism for "allow". James B. Shearer ========================================================================= Date: 3 May 1994, 11:12:32 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Re: Population (Was Feeding 15 billion ...) Steinn Sigurdsson posted: > ... A too rapid decline >will invert the population profile. Under current >social and technological systems this would be >disasterous, there would be a crash as the aging bulge >could not be supported, ... I find this difficult to believe for plausible rates of population decline. The larger number of unproductive old people would be balanced by a smaller number of unproductive young people. In any case I don't see how increased death rates for old people could cause a crash for the population as a whole. How about some evidence for this assertion? James B. Shearer ========================================================================= Date: 4 May 1994, 20:03:21 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Demographics Kevin Brown posted: >Have you done the calculations on this plan? If each generation is 25 >years, you'll have 8 generations in order to make this happen. The >average person lives about 3 generations (75 years). Thus, 1/3 of your >population dies each generation. According to my calculations, you'll >need a 25% reduction in population per generation to achieve, in 8 >generations, a population of 10% of the existing one. My calculations >based on this say that, for each generation, only 8 percent of the >population may reproduce. Or, rather, 16 percent of the couples may >have one child in each generation. Your calculation is incorrect. Population will be reduced by 25% each generation if each couple has 1.5 children on average (as should be obvious). Your calculation contains two serious errors. You assume the oldest generation (which is dying) is the same size as the youngest generation (which is reproducing). However in a decreasing population the oldest generation will be larger. Further- more since it is only the youngest generation which is reproducing your 8% children represents .48 children per couple. James B. Shearer ========================================================================= Date: 9 May 1994, 23:12:58 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Economics Michael Tobis posted: >That's my reading of why per capita income is stagnant while per capita >hours worked have skyrocketed. ... Disposable per capita personal income in the US (in constant 1987 dollars) was $12005 in 1980, $14068 in 1990 (source Statistical Abstract of the US, 1993 edition, table 696, p. 445). This is not what I would call stagnant. Michael Tobis also posted: >When the trend was originally spotted, the predictions were that we would end >up with a "leisure society", that we would have more time on our hands than >we know what to do with. Feeling like you have too much time on your hands, >lately? Anyone who posts to netnews obviously has time on his hands. Michael Tobis again: >I think that the trend went the opposite way is due to a failure to think >through the social implications of the economic implications of a decreased >demand for labor. What evidence do you have for your apparent belief that we are currently observing a decreased demand for labor? Over what time period? John McCarthy posted: >My opinion is that the reduced middle class standard of living of >recent years was caused by waste. Here are some kinds of waste. What "reduced middle class standard" are you referring to? James B. Shearer ========================================================================= Date: 9 May 1994, 23:46:03 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: population Steinn Sigurdsson posted: > ... A too rapid decline >will invert the population profile. Under current >social and technological systems this would be >disasterous, there would be a crash as the aging bulge >could not be supported, ... I responded: > I find this difficult to believe for plausible rates of >population decline. The larger number of unproductive old people >would be balanced by a smaller number of unproductive young people. >... > How about some evidence for this assertion? Kevin Brown responded: >Do the calculations. See what results *you* get. I'm going to write a >quick and dirty simulation to see what results I get. First to clarify by "young people" I meant children. Here are the results of a "quick and dirty simulation" Assume number of births changes by a constant factor each. Assume the chance to live to age t is: 1.00 for t<30 exp(.005*(1-exp(.1*(t-30)))) for 30120 (Life expectancy with this model is 77 years somewhat in excess of current US value). I computed the age distribution for growth rates of -2%,...,4%. The results I got were: age distribution population 200 year multiplier 0-20 20-65 65+ /births multiplier 0.98 0.13 0.55 0.32 189.82 0.0176 0.99 0.19 0.57 0.24 117.20 0.1340 1.00 0.26 0.57 0.17 77.00 1.0000 1.01 0.34 0.54 0.12 53.70 7.3160 1.02 0.42 0.50 0.08 39.55 52.4849 1.03 0.50 0.45 0.05 30.54 369.3558 1.04 0.58 0.39 0.03 24.55 2550.7498 These results do not support the original assertion by Sigurdsson. James B. Shearer ========================================================================= Date: 12 May 1994, 15:50:12 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: population also demographics Steinn Sigurdsson posted: > ... A too rapid decline >will invert the population profile. Under current >social and technological systems this would be >disasterous, there would be a crash as the aging bulge >could not be supported, ... I replied > I find this difficult to believe for plausible rates of >population decline. The larger number of unproductive old people >would be balanced by a smaller number of unproductive young people. >In any case I don't see how increased death rates for old people >could cause a crash for the population as a whole. > How about some evidence for this assertion? Steinn Sigurdsson responded: >If you want hard evidence it is hard to come by, as no population >to my knowledge has ever had an inverted demographic profile. >Europe and Japan are just about to get to the point where >the retired cohorts are larger than the prepubescent cohorts. > >However, it is easiest to see in economic terms. The old population >needs care or they die. The care "costs" money, think something like >the US social security system. In practical terms, care for the >elderly is manpower intensive and by being "retired" they do not >contribute much to production of food and other essentials. >So, if the population profile is too top heavy, how do you >provide this care? If you don't, the people die. Then you still get >the population reduction proposed, but by drastically lowering >life expectancy, not primarily by lowering birthrate. > >This would appear to me to be unstable, either the demand for manpower >forces up the birthrates or there is social and economic crash >with a sharp reduction in life expectancy. You provide the care with all the money you no longer have to spend on children. Furthermore supporting unproductive old people is a luxury, if the burden on society becomes too great this support will be reduced or eliminated. This would not cause a drastic decrease in life expectancy and would have little effect on population size in the long run. Steinn Sigurdsson also posted: >See the toy model I posted yesterday, in particular look at the >time frame 2050-2075 in the model. For that initial population >distribution, no change in death rate and US level life expectancy, >the ratio of workers:retirees gets as low as 1:3 (assuming current >retirement policies). This is considered a problem in most >economies. Ok let's look at your model. I have computed the fraction of the population of productive age (20-64 assuming 20-32 is 75% of 16-32) in 1994 and 2058. It increases from 40.17% in 1994 to 58.69% in 2058 (fewer children outweighs more elderly, btw I don't believe 50% of the world's population is currently under 16). Hence by your own model productive workers would represent a greater fraction of the population in 2058. Where is the problem? In any case your model is a strawman, since it represents a population decreasing in size by over 4% a year far in in excess of the rate proposed by McGowen (90% in 200 years is a bit over 1% a year). James B. Shearer ========================================================================= Date: 19 May 1994, 17:43:13 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: population and demographics I posted (in response to a model posted by Steinn Sigurdsson which he claimed showed a declining population would produce an age distribution with an unsupportable number of old people) > Ok let's look at your model. I have computed the fraction of >the population of productive age (20-64 assuming 20-32 is 75% of >16-32) in 1994 and 2058. It increases from 40.17% in 1994 to 58.69% >in 2058 (fewer children outweighs more elderly, btw I don't believe >50% of the world's population is currently under 16). Hence by your >own model productive workers would represent a greater fraction of the >population in 2058. Where is the problem? Steinn Sigurdsson responded: >I have no idea where people get the idea that children >are resource intensive. They're not. Children are cheap >compared with older people. Ok, let us assume old people are twice as expensive as children. Again using the figures in your model the ratio of old people equivalents ((64+)+.5*(0-20)) to people of working age (20-64) decreases from .79 at present to .65 in 2058. Still no problem. Are you perhaps assuming third world standards for children, first world standards for the elderly? Steinn Sigurdsson also posted: >I am somewhat at a loss here. Your assumptions about the relative >economic burden of children, workers and retirees appear to be >completely different from anything any economists I know figure. Ok, let me quote an economist (Lester C. Thurow, "Head to Head", 1992, p205-207) "... It is simply impossible for any country to become rich in the context of a rapidly rising population. The reasons are simple. To make new human beings into modern productive workers takes a lot of investment. ..." "A few American numbers illustrate the problem. ... Basic- ally, each new American will require an investment of $240,000 before he or she is capable of fitting into the American economy as a self- sufficient, average citizen-worker-consumer." Steinn Sigurdsson also posted: >Let's see. Imagine you plan to fund the cost of the "retirees" >by investing a proportion of their current earnings. >By the time the cohort reaches retirement the workforce has >decreased, you either have to invoke magic technology >whereby capital can be converted to production without >a labour supply (a heavily robotic economy might work) >or you face inflationary pressures from the labour scarcity. >This wipes out the investment and you either have to >tax the working cohorts or let the retirees go bankrupt >(and die?). You can translate that into any economic support >system you care, you either face a shortfall of resources >or you need magic technology to meet the demand. It is easy to substitute capital for labor. For example mechanizing agriculture in the third world would free an enormous amount of labor. This does not require "magic technology". Steinn Sigurdsson also posted: >If you look at it in US or European terms, "retirees" expect >much higher per capita disposable income than children do. >Of course, as John noted, if you lower your retirement >expectations far enough, this is not a problem. In other words your original claims of disaster were wrong. I posted: > In any case your model is a strawman, since it represents a >population decreasing in size by over 4% a year far in in excess of the >rate proposed by McGowen (90% in 200 years is a bit over 1% a year). Carl Lydick responded: >McGowan started out demanding 90% reduction in 50 years. Then for quite some >time, he was demanding a 90% reduction in 100 years (which is what Steinn's >model did). It's only been in the past month (when he was once again >challenged to support his claims) that McGowan has backed off to a 90% >reduction in 200 years. Arguing against a withdrawn proposal instead of the current proposal seems like a typical strawman tactic to me. James B. Shearer ================================================================================ Date: 22 May 1994, 11:39:16 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Re: Population and demographics I asked Stein Sigurdsson (regarding his claims that a declining population could not support its elderly): > Are you perhaps assuming third world standards for children, >first world standards for the elderly? Steinn Sigurdsson replied: >No, I'm assuming a consistent standard for both. First world. >Specifically that the elderly will receive the current first >world level of health care to maintain life expectance and >a retirement income to maintain a comparable living standard. So your criticism of McGowen's proposal for a declining world population is that it will not provide a first world standard of living for the all the world's elderly. Perhaps you will explain why you think all the world's elderly will enjoy a first world standard of living if we proceed along our present course. Otherwise your criticism seems a bit disingenous to say the least. James B. Shearer ========================================================================= Date: 22 May 1994, 11:58:52 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Science and Policy Robert Parson posted: >I think Rich is trying to tell us that such positions *appear* arrogant >and insensitive. This is a very important point for those of us who are >trying to communicate scientific information with the public. When the >public sees scientific advisors either as beholden to one or another interest >group, or as constituting an interest group in its own right, then we've >lost, no matter how false the perception may be. This extremely simple >point is finally beginning to sink on over on my end... Scientists are an interest group. As a group they receive a large fraction of their income from the government and they employ lobbyists to promote their interests. Pretending otherwise is silly. James B. Shearer ========================================================================= Date: 22 May 1994, 22:31:45 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Subject: recent history (was Science and Policy) Michael Tobis posted: >The history of democracy shows that democracy is not infallible. The >Falklands incident showed that democracy (both the UK and Argentina were >democracies at that time) is not a surefire cure of even the most stupid >pointless wars. Democracy is vulnerable to demagoguery, and the price of it, >eternal vigilance, can never be paid in full. Argentina was not a democracy during the Falklands war. It was led by a military junta. The dominant figure was General Leopoldo Galtiera, president and army commander. James B. Shearer ========================================================================= Date: 23 May 1994, 16:48:47 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Risk John McCarthy posted: >The $7.5 million is the conclusion of a peer reviewed article. When I >did the correlation myself in 1983 between personal income by states >and death rate by states I got $2.5 million but didn't try to publish. Rich Puchalsky replied: >I'd be interested in the reference to the article, if you still have it. I too am interested in the exact reference (or a summary of the methodology). Did you personally find the paper persuasive? Regarding your $2.5 million figure, if all you did is compute the correlation between two lists of 50 numbers, the number of alternative explanations is mind boggling. Rich Puchalsky also posted: >Now, if this were a peer reviewed paper, that would be a different story. >But that's my whole point! This kind of thing should stay in academia, >where the methods used are more trustworthy. As soon as it is done >as part of government, I lose any trust in the numbers. Try figuring >out the real U.S. budget deficit sometime if you don't understand what >I mean. I trust our system of government to work out competing interests >politically; I don't trust it to calculate numbers accurately. I think you are displaying an unjustified faith in the peer review process. I suspect the average government report of this type is at least as accurate as the average peer reviewed paper. Academic work can also be ideologically biased. I also believe you will find that most academic work in the social sciences relys heavily on govern- ment numbers. Do you believe the interplay of competing political interests has produced a rational risk regulation system in the US? You earlier indicated that you believe that coal mining should be made safer. However there is no easy way to do this without encouraging a shift in production from dangerous eastern underground mines to safe western surface mines. As a result eastern politicians block change. Do you believe the system is working well in this instance? James B. Shearer ========================================================================= Date: 2 June 1994, 18:10:37 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: risk John McCarthy has suggested that the USA should not spend more than 7.5 million dollars to prevent a typical death. This is based on a claim that a paper has shown that taking 7.5 million out of the general economy will cause a death (on average). I will give a different argument that the USA should not spend more than about 3 million dollars to prevent a typical death. The argument is simple. There are about 2 million deaths per year in the USA and total GDP is about 6 trillion dollars. Clearly the USA would not spend more than total GDP to prevent all deaths. 6 trillion dollars to prevent 2 million deaths is 3 million dollars per death. Since I see no reason to value the first death prevented substantially more than the 2 millionth I would argue that the USA should be unwilling to spend more than about 3 million dollars to prevent a single typical death. Some additional points: 1. Actually the USA would be unwilling to spend the entire GDP to prevent all deaths which would reduce the above estimate. 2. On the other hand most regulations to prevent deaths will have additional benefits which should also be considered. 3. The above argument applies to typical deaths. If the deaths prevented by a regulation are atypical (for example deaths of young healthy people) this could justify spending more per death prevented. James B. Shearer ========================================================================= Date: 2 June 1994, 19:02:24 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: risk Rich Puchalsky posted: >It is obvious that I could have posted a list of imaginary ways to make >the risk appear 3 orders of magnitude greater. I challenge you to >find a single real-life example of risk assessment being misused by >an environmentalist in such a manner. In fact your example about >microwaves has nothing to do with a misuse of risk assessment. Lack of such examples may have more to do with the fact that most environmentalists refuse on principle to perform cost- benefit analysis than with any greater scruples on their part. I would suggest one possible example, the reactor safety numbers produced by the Union of Concerned Scientists (UCS). There are other ways of misleading people not mentioned in your original post which environmentalists (among many others) do do in real life. I will list a few. 1. Abuse of statistics, in particular exaggerating the odds against something occuring by chance. If we flip one coin 10 times and observe 10 heads then we can correctly say that such a surplus of heads would only occur about 1 time in 1000 by chance with a fair coin. If we flip 1000 coins 10 times each and observe 10 heads for coin 722 it is incorrect and grossly misleading to make the same statment for coin 722. Yet results of epidemiological studies are often reported in this way. If we do a study of workers in a plant and consider enough diseases (various cancers, strokes, heart attacks etc) and enough subgroups of the workers (men, women, white, black, old, young etc) we are bound to find groups with a "statistically significant" increase in the incidence of some disease considered in isolation. (Statisticians by convention consider a result significant if there is less than a 5% chance it occurred by chance. 5% is an arbitrary level, more generally statisticians say a result is significant at the x% level.) However since we didn't perform this test in isolation it is wrong to report the results as if we had. A sign that this has happened is skeptics pointing out that by the same criteria other groups of workers would show a "statistically significant" decrease in the incidence of some other disease. A related abuse would be to flip the same coin 1000 times, observe 10 heads starting at flip 347 and report that the chance getting all heads with a fair coin between flips 347 and 356 was less than 1 in 1000. Yet reports of disease clusters often report misleading odds in this way. If one is looking at miscarriages among women in a certain building for example one has numerous ways of drawing lines to define the group of pregnancies being considered. A judicious choice will inflate the calculated odds against such a rate of miscarriages having occurred by chance. For example, should we consider the entire building or just certain floors, what time period should we look at, should we look at all women or some sub- group, should we look at miscarriages or "adverse pregnancy outcomes" instead etc. 2. Jumping to cause and effect conclusions from observed correlations. If group X has a more of trait A and a higher inci- dence of disease B than group Y, there are many possible explanations other than A causes B. Yet jumping to such conclusions is common, for example that differences in disease incidence between countries are caused by differences in diet. 3. Abuse of anecdotal evidence. For example: i: Jane Doe died of brain cancer. ii: Jane Doe used a cellular telephone a lot. iii: Therefore cellular telephones cause brain cancer and should be banned. Rich Puchalsky also posted: >When Mr. McCarthy gets around to actually reading my post, he might >want to address the issue of why these kind of safety issues appear >to be listed with a better cost/benefit ratio than health issues. >I thought the skewed distribution in the table was quite striking >and not likely to be due to chance (I've explained my hypothesis >for the distribution in the post). My explanation would be that cancer has a greater "dread factor". People fear hidden dangers (cancer from radiation) more than obvious dangers (auto accidents). Perhaps this is because if you can perceive a danger it is easier to believe you can avoid it. James B. Shearer ========================================================================= Date: 12 June 1994, 12:25:41 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Risks John McCarthy posted: >French nuclear plants produce electricity at 4.5 cents per kwh and >generate 80 percent of France's electricity with considerable left >over for export. The U.S. could do as well, and indeed some >U.S. plants do. Don't US coal burning generating plants do considerably better? James B. Shearer ========================================================================= Date: 12 June 1994, 12:32:11 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: Risks Barry Smith posted: >Care to describe the catastrophic failure modes of any conceivable >solar energy system that result in hundreds or thousands of prompt >fatalities? You appear to be forgetting the orbital proposals. Barry Smith also posted: >Yes, and many people avoid flying due to fear of just that happening, >and insurance companies make lots of money off that "unreasonable" >fear. Airplanes also don't present a significant risk to those who >choose not to use them, and don't cause significant collateral damage >when they crash. Numerous people have been killed by airplanes falling on them. What is your definition of significant? James B. Shearer ========================================================================= Date: 19 June 1994, 22:15:25 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: climate Michael Tobis posted: >So Carl is right that it's not demonstrably impossible that the *ultimate* >result will be cooling. However, it is demonstrably impossible that a >*small, gradual and insignificant* cooling will occur in response to >increasing greenhouse gases. Small perturbation geophysical feedbacks don't >reverse the sign of an output: if an increase in temperature provokes a >cooling feedback (say, more reflective clouds) then once there were enough >such clouds to decrease the temperature, the phenomenon would go away. This is wrong, feedback can reverse the sign of an output. Consider the following system: y'=B*y with y= y1 B= -4 3 y2 -2 1 The eigenvalues of B are -1 and -2 so y1=0, y2=0 is a stable equlibrium solution of this system. Now introduce positive forcing on y1 ie y'=B*y+a with y= y1 B= -4 3 and a= 1 y2 -2 1 0 The new stable equilibrium solution is easily seen to be y1=-.5, y2=-1. The exact solution with initial conditions y1=0, y2=0 at time t=0 is y1= 2.*exp(-t) -1.5*exp(-2.*t) - .5 y2= 2.*exp(-t) -1.0*exp(-2.*t) -1.0 Hence although the initial impact of the forcing is to increase y1, the interaction with y2 causes the eventual impact of the forcing on y1 to be negative. James B. Shearer ========================================================================= Date: 19 June 1994, 23:28:56 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: ice ages Michael Tobis posted: >This sudden-onset-of-ice-age theory was prominent in the 1970s, but isn't >given much credence nowadays. (Before anyone brings up the Younger Dryas >event again, note that that event was due to a sudden advance of existing >glaciers, not a sudden asppearance of glaciers.) On the time scale on which >an ice age could start due to a cooling of N degrees, the Greenland and >Antarctic ice caps could easily melt significantly due to a warming of N >degrees. A rise in some tens of meters of sea level is not generally >considered a benign result. On what basis have rapid onsets of ice ages been ruled out? How about some references? What is "the time scale on which an ice could start"? James B. Shearer ========================================================================= Date: 19 June 1994, 23:38:38 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: CO2 Michael Tobis posted: >Since the CO2 has very long residence times while the aerosol has short >residence times, while both are tied to fossil fuels, note that the CO2 >will accumulate while the aerosol will not. Thus, the warming effect tends to >dominate on longer time scales. What do you mean by "very long residence times"? Michael Tobis also posted: >If current theory is anywhere near correct, we have to assume that >eventually emissions rates will stop increasing exponentially - otherwise >the results will be cataclysmic. Then the final CO2 concentrations depend >very sensitively on the year in which emissions stop increasing. If we >stop in 1990, as we have promised ourselves to do, we will have to deal with >CO2 doubling, more or less, while if we stop in 2030, our descendants will >have to deal with quadrupling. Of course, if in 2030, we manage to suddenly >drop emissions to 1990 levels, we will not have lost much. Hasn't this come up before? Didn't we conclude that holding emissions to current levels would not lead to CO2 doubling? James B. Shearer ========================================================================= Date: 21 June 1994, 11:12:55 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: CO2 Michael Tobis posted >Since the CO2 has very long residence times while the aerosol has short >residence times, while both are tied to fossil fuels, note that the CO2 >will accumulate while the aerosol will not. Thus, the warming effect tends to >dominate on longer time scales. I asked: > What do you mean by "very long residence times"? Michael Tobis responded: >The atmospheric residence half-life of aerosol is about a year, and that of >CO2 is about a century. I hope we are talking about the same thing, namely the half life of excess (above natural or equilibrium levels) CO2. If so, and if the half life is 100 years, why is only about 50% of anthropogenic CO2 still in the atmosphere. This suggests to me a half life more like 25 years. I also posted (in response to a claim that holding CO2 emissions to current levels would lead to CO2 doubling): > Hasn't this come up before? Didn't we conclude that holding >emissions to current levels would not lead to CO2 doubling? Michael Tobis responded: >I may have missed it if it came up before. I refer you to figure 4 section 1 >of IPCC 1990. The projection shows that holding emissions to 1990 levels >delays doubling until after 2100. There are, of course, a lot of uncertainties >in such a projection, but daring to project it past 2100 it looks like >the equilibrium level in the distant future will be shy of triple background, >at least until the carbon runs out. (This is CO2 alone and leaves out other >greenhouse gases.) Last November you posted a claim that an 80% reduction in current CO2 emissions would be required to stabilize the CO2 level in the atmosphere. I queried this and suggested a 50% reduction would suffice. As I recall you accepted this. It would seem to follow then that holding CO2 emissions to current levels would lead to an eventual doubling of the current excess. Since it is my understanding that the current excess is about 25% of background this would be a final level 1.5 (not 2) times background. I have no access to IPCC 1990. How is their projection derived? James B. Shearer ========================================================================= Date: 21 June 1994, 21:00:36 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: ice ages Michael Tobis posted: > This sudden-onset-of-ice-age theory was prominent in the 1970s, > but isn't given much credence nowadays. [ ... ] I asked: > On what basis have rapid onsets of ice ages been ruled out? > How about some references? What is "the time scale on which an ice > could start"? Jan Schloerer commented: >Look, Michael Tobis did not say that sudden onset of glaciations >has been "ruled out" but that it "isn't given much credence". >Given my admittedly gappy English, I tend to translate that as >"it is not considered very likely". I consider this a quibble. However I will modify my question. Why was this theory credible 20 years ago, but not now? Jan Schloerer also posted: >One simple reason is that a large ice sheet takes time to grow. >It won't get really large just in a few years. That is rather >a matter of thousands of years. Presumedly this was considered 20 years ago. There is a definitional question here. Suppose the earth's average temperature abruptly drops 5 degrees C. I would consider this a rapid onset even if the resulting ice sheets formed more slowly. Are abrupt changes in the earth's average temperature also considered unlikely? If so is this based on observation or simply lack of a plausible mechanism? James B. Shearer ========================================================================= Date: 21 June 1994, 21:53:33 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: regulation Michael Tobis posted: >A responsible, rational, and respected regulatory process may threaten the >job security of professional lobbyists on all sides, so they can be expected >to oppose it on their own behalf rather than their consituencies'. In all >other respects it would serve the public interest, and public debate could be >focussed on larger principles that would guide the regulatory bodies, rather >than on petty thrashing about with generally random and all too regularly >stupid results. What makes you believe a "responsible, rational and respected regulatory process" is achievable? Can you point out existing examples? Cheap power from fusion would be nice too. In any case your statement that the only people who would be hurt by such a process would be professional lobbyists is wrong. Presumedly such a process would increase the amount of money spent on cleaning up toxic waste sites and reduce the amount of money spent on lawyers arguing about cleaning up toxic waste sites. Lawyers are of course an extremely powerful constituency (which is why the present situation exists, it is not a random accident). James B. Shearer ========================================================================= Date: 23 June 1994, 18:38:57 EDT From: JBS at YKTVMV To: usenet-poster at polecat.newsgate.ibm.com Newsgroups: sci.environment X-Post-Me: Yes Subject: ice ages David Halliwell posted: > Approximately 20 years ago, there was a suggestion that continental >ice sheets *could* grow rapidly. Instead of growing in "source" regions >and spreading out laterally, the idea was presented that snow would >accumulate over large areas and then would not melt in the summer. >Therefore snow/ice extent would increase rapidly, as opposed to slowly. > > I'm not real up-to-date about thinking on the subject, but a primary >reason for assuming that ice sheets won't appear suddenly is a general >acceptance that glacial and interglacial periods are the result of orbital >changes with periods of 20,000-110,000 years. These changes (usually >refered to as the Milankovitch cycles) simply don't happen in a hurry. > > 20 years ago, there were more hypotheses about causes of glacial >periods. As alternate hypotheses have fallen out of favour, the time >frame required for orbital changes predominates. I was under the impression that the relationship between the orbital cycles and ice ages was speculative and uncertain. In this connection how accurate are calculations of these cycles. (I vaguely recall a recent significant change in the calculated period of one of these cycles.) In any case your argument that slow changes in forcing imply slow changes in response is unconvincing. Changes in forcing can shift the position of a stable equilibrium or they can cause it to disappear. In the second case a small change in forcing can cause a major change in response as the system moves from a point which has become unstable to a new equilibrium which may be far away. In the case of climate, orbital forcing could cause a low ice cover climate to