Recent Comments
Prev 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 Next
Comments 105551 to 105600:
-
Joe Blog at 11:25 AM on 28 October 2010What should we do about climate change?
Marcus says & average efficiencies are pushing 20% (with efficiencies in the lab of around 42%). Can nuclear power make the same claims? Yes, well over the 90% range for turbine efficiency, yah can run the turbines at 1800C(big difference between that and 15C), the 95% figure, is a lower end estimate of mass converted to energy(E=MC^2 n all eh)... there is no comparison. The old nuclear plants, were, are designed for the purpose of producing nuclear weapons, electricity was the bi product. And whats more... they(fast breeders) can theoretically be built small enough to power aircraft... think o the GHG savings there;-) that may be pushing it. -
Marcus at 11:19 AM on 28 October 2010What should we do about climate change?
So quokka, do you *really* believe that coal & nuclear are as reliable as you'd have us believe? Centralized power plants are subject to all kinds of faults between the point of production & the point of consumption. Also, do you *honestly* believe Coal Power stations don't have to be shadowed to some extent, in case of breakdowns? Like I said before-but you've chosen to ignore-claims about variability are usually made by those living in a TIME WARP. Massive improvements in relatively cheap storage technology has made the issue of variability in renewable energy practically moot. Also, how does your argument stack up when looking at energy sources like Tidal Streams, Run-of-River Hydro-electricity or Landfill Gas, which are completely capable of supplying reliable base-load power *without* the need for additional back-up? -
quokka at 11:16 AM on 28 October 2010What should we do about climate change?
#53 Marcus, "quokka, have you not heard of Vanadium Flow Batteries". Apparently these were first patented in 1986. One has to ask why it is 24 years later that there is no significant deployment of these things anywhere in any grid. Everybody would love inexpensive storage, not just to support renewables, but to deal with peak load requirements in existing grids. I'm as much for the next big thing as the next person, but if it cannot feasibly be used as a substitute for the next coal fired plant to be built in the next five years, then that next big thing is something to keep an eye on but no more than that. Remember that those new coal fired plants will have a life of several decades and once built, they will be very hard to get rid of. It is imperative that we do not fall into the really dangerous trap of mistaking our wishes for the engineering and economic realities of what can actually be done. This has been referred to with some justification as a "technological cargo cult". -
Marcus at 11:14 AM on 28 October 2010What should we do about climate change?
Peter Lang, if "Renewables are Unproven" is your only criteria for dismissing it, then why in the *hell* did any country ever embrace nuclear power? In 1950, that technology was "unproven" too. As I recall, the proponents of nuclear power claimed it would be "too cheap to meter", yet it still remains one of the *highest* cost sources of electricity after *sixty years* of intensive public & private funding. The only reason France differs is because the French Government heavily subsidized the nuclear industry when Electricitie de France was was publicly owned. These days, EdF is one of the most heavily indebted companies in Europe-hardly a great advertisement for nuclear power. As I said above, take a look at the *real* costs of nuclear power, compared to those quoted by the WNF, & tell me that the nuclear industry isn't being over-optimistic in their calculations. Also, cost & time overruns are the *norm* in the nuclear power industry-not the exception, whereas the bulk of the renewable energy projects I've read about were completed ON TIME & ON BUDGET. Indeed, based on the examples I've given above, I'd agree that nuclear power *is* proven-a proven WHITE ELEPHANT! By contrast, have a look at photovoltaics. In 1982, the year the sine-wave inverter was invented, the average price of a solar cell was US$25 per watt & had an average efficiency of barely 5%. Just 28 years later, & the cost is currently $3 to $4 per watt, & average efficiencies are pushing 20% (with efficiencies in the lab of around 42%). Can nuclear power make the same claims?Moderator Response: Please don't use all caps. -
Joe Blog at 11:04 AM on 28 October 2010What should we do about climate change?
"short o vaporizing a plant, the dangers are greatly reduced from the traditional nuclear plants." this sentence reads wrong, What i mean is, for you to get the same kinda disaster as at say Chernobyl, would require you to drop a Daisey cutter on the plant, and atomize the coolant/plant in general. Not that the plant can vaporize itself, passive safeties n all, even if all people suddenly turned in zombies and eat our selves into extinction, the plants would simply shut themselves down. As a result of time. -
Peter Lang at 10:53 AM on 28 October 2010What should we do about climate change?
Argus, "And, also, thank you Marcus, for debating with these nuclear power proponents with their overoptimistic calculations! What is the basis for implying that the nuclear figures are over-optimistic but the renewable figures are not? Nuclear is proven technology. Renewables are not. Whereas the nuclear figures are based on 50 years of actual recorded history, the renewables projections are based on hope and wishful thinking. So which is optimistic? France, 80% nucelar, lowest emissions from electricity of any major country, least cost electricity, and it is reliable! What is the goal? Cut emissions or promote ideological beliefs? -
quokka at 10:51 AM on 28 October 2010What should we do about climate change?
Marcus, Price per name plate capacity quoted in MWe as an indicator of the cost of generating electricity is extremely misleading. We can see how misleading this can be by considering the capacity factor. For on-shore wind this is in the range 25-30%, for solar PV in for example Germany it is no more than 12%, for solar thermal with storage it varies but there are no existing plants than come anywhere near the 90% or so typical of coal and nuclear. A starting point for discussions of costs needs to be LCOE per kWh. But that is not the end of the story. What really matters is the overall system cost. Variable sources of electricity whose variability cannot be controlled must be backed up or shadowed by something that can be controlled. It could be done with storage eg pumped hydro, partially by extra transmission capacity to geographically distant sources or extra generation capacity - possibly gas. Whatever it is, it also costs money and makes the true system costs of solar and wind higher than the LCOE figure would suggest. It is time to stop playing games with the issues of energy and demand the same sort of rigor that is rightfully demanded in discussions of climate. -
Argus at 10:45 AM on 28 October 2010What should we do about climate change?
Thank you Tarcisio José D'Avila (#48)! You did a lot better in your four lines than this Kevin Judd figure. And, also, thank you Marcus, for debating with these nuclear power proponents with their overoptimistic calculations! -
Daniel Bailey at 10:42 AM on 28 October 2010What should we do about climate change?
Re: michael sweet (53) Uhmmm, Pakistan is already nuclear. That ship has sailed, as they say. The Yooper -
Joe Blog at 10:41 AM on 28 October 2010What should we do about climate change?
michael sweet The breeder reactors are a lot safer than the water reactors.. They use the liquid fluoride(thorium salt) as the coolant, which has a very high boiling T(off top o my head around1600-1800C) But its also part of the reactant, so you can basically just run frost plugs in your reactor chamber, that will drop the coolant into a separate chamber, stopping the reaction in the case of over heating. The thorium salt absorbs the radiation, and is stable/ it wont burn, or dissolve in water etc.. The premise i believe is to run processing plants that process the coolant into fissionable fuel, which is a result of the atomic breakdown from absorption of the radiation... so they make their own fuel(uranium), from thorium. They also can use nuclear waste from the old plants as fuel. Now they actually convert OVER 95% of the fissionable material into energy(as opposed to the couple o percent of water reactors) The reason why they havnt been heavily developed, is mostly because the water reactors are better for getting the materials for nuclear weapons. The japanese have some. They have huge potential, and can operate with passive safties... short o vaporizing a plant, the dangers are greatly reduced from the traditional nuclear plants. -
Daniel Bailey at 10:26 AM on 28 October 2010Isn't global warming just 2 °C and isn't that really small?
Re: mfripp (28) While not Minnesota, Illinois (depending upon the emission scenario) gets a lot hotter, too:The rest of the Midwest will follow along similarly. Source here. The Yooper
-
Joe Blog at 10:10 AM on 28 October 2010The 2nd law of thermodynamics and the greenhouse effect
@nealjking In no way am i saying the greenhouse effect is a contradiction of the second law... but i think the example of the net flow of heat being from hotter to colder, should be seen as a result of the second law, not the second law... Entropy increases or stays the same, is the second law. And its simply stating the behavior of energy. That chaos increases, a body with a high T has confined chaos, and it will increase, the hotter the body, the more confined the chaos, the more efficiently that chaos increases. It behaves the opposite to matter/gravity basically. So as a result of this, a hotter object will have greater increasing chaos than a colder object, put simply. To test if the earth has decreasing entropy, switch off the sun, if it heats, its in violation o the second law;-) And energy locked in chemical bonds entropy stays the same... till yah burn it, then its chaos increases. Decreasing entropy implies the clumping together of energy from lower to higher concentrations. -
michael sweet at 10:06 AM on 28 October 2010What should we do about climate change?
I am agnostic about nuclear power, but I think we need to consider that any solution must work for the entire world. Do we really want Pakistan and Nigeria to build a bunch of thorium reactors? Will those reactors really be terrorist proof? (Claims about "fanciful" worries seem to pale when we talk about Nigeria and Zimbabwe building reactors). Solutions must work for everyone, not just the developed world. I do not mind if Pakistan builds a bunch of wind generators, but I have my doubts about thorium reactor safety in the third world. -
Daniel Bailey at 10:05 AM on 28 October 2010Skeptical Science Firefox Add-on: Send and receive climate info while you browse
I used Opera for my browser in lieu of IE...until Firefox 3 came out. Made the jump without regret. Still use Opera on my cellphone, but has limited commenting functionality there for SkS. With my Internet access being down for now (just moved to a different house and work has yet to have the 3rd party vendor implement the change), I'm reduced to phone browsing and various hotspots (not many in this rural area). The Yooper -
Steve Metzler at 09:52 AM on 28 October 2010Phil Jones says no global warming since 1995
Late to the party here, but first time poster and all that... There is some very interesting background to that BBC interview of Phil Jones. The Beeb were trying to be 'balanced', and so invited (some) questions from prominent climate skeptics. That "Do you agree that from 1995 to the present there has been no statistically-significant global warming?" question in particular was in fact carefully crafted by Lubos Motl (and Steve McIntyre may have had a hand in there too, not sure) to paint Dr. Jones in a bad light. They knew he had to answer it honestly, but it was a loaded question. If you go back even *one year* to 1994, or in fact any year before that, then the warming is statistically significant to the 95% confidence level. As most of you know, you really can't consider periods shorter than 22 years because of the influence of solar cycles. 15 years is not nearly long enough. Motl and McIntyre know this, of course. So this is what climate science is up against: clever little deceptions and spin to score cheap points in the eyes of the public. -
Marcus at 09:47 AM on 28 October 2010What should we do about climate change?
quokka, have you not heard of Vanadium Flow Batteries? If these were built (& I see no reason why they haven't, as they wouldn't add significantly to the cost of a wind power project), you'd be able to store several hundred megawatts of excess Wind Power for release when there is no wind power to be had. The fact is that storage & good placement of wind turbines can remove pretty much *all* of the variability experienced by wind power-yet funny how that argument is still bandied about by the anti-renewable squad! -
Marcus at 09:43 AM on 28 October 2010What should we do about climate change?
Peter Lang, like it or not, many of the life-time electricity costs for nuclear power are based off the assumed capital cost of $1,990/KWe-which comes directly from the World Nuclear Federation. Experience over the last 3 years, though, shows a very different cost for nuclear power. Florida Power & Light estimated the cost of 2 AP1000 reactors in 2008 to come in at around $3100/KWe to $4500/KWe ($6,000 to $8,000 when finance charges were added in). Duke Energy Carolinas is building two AP1000 reactors for a total cost of $11 billion-or around $5,500/KWe. Georgia Power Company is contracted to build 2 AP1000 reactors for a total cost of $17 billion (including $3 billion for transmission upgrades). Excluding transmission upgrades, this gives a cost of around $7,000 per KWe. Then you have the Olkiluoto Power station, which is already costing EU$3,800/KWe, but hasn't even been completed yet. This cost is in *spite* of SIXTY YEARS of Research, Development & Construction of Nuclear Power Stations-not to mention significant public & private investment-compared to the relatively short life span of the Concentrated Solar Power industry (SEGS only went online in 1991). It really does show up the weakness of the pro-nuclear argument! -
quokka at 09:33 AM on 28 October 2010What should we do about climate change?
#36 Alexandre You can see the wind output from South Australian wind farms, together with demand and price charted nicely here: http://www.oz-energy-analysis.org/data_viewer/dv1a.php . Scroll over the data to get a general sense of variability. Note that in May, there were two weeks with almost no electricity generated. -
johnkg at 09:21 AM on 28 October 2010What should we do about climate change?
#49. Have the decommissioning costs been factored into the price of nuclear generated electricity as well? I'm not anti-nuclear, but I don't want to fix one problem (AGW), just to replace it with another. -
climatesight at 08:47 AM on 28 October 2010Skeptical Science Firefox Add-on: Send and receive climate info while you browse
Awesome! This might actually make me consider Firefox....I'm a Chrome die-hard. Maybe it could be my backup browser (for when CSS issues come up) and I could uninstall IE, that would make me happy. Shine Tech sounds like a great company. Will there be app updates when the beginner-intermediate-advanced rebuttals are complete?Response: When the beginner/intermediate/advanced idea was first suggested to me, the first thing I did was ask Shine whether it was feasible to include it in the iPhone app (and my not-so-secret hope, an iPad app). They said yes - I don't know when it would happen, keeping in mind Shine are doing this all for free and thus have limited resources to devote to the iPhone app. -
Alexandre at 08:44 AM on 28 October 2010Skeptical Science Firefox Add-on: Send and receive climate info while you browse
Great add-on. Already installed. I wonder if there's some policy about submitting articles in other languages?Response: Hmm, hadn't really thought about it. I suppose a language drop down could be a future feature if there's much call for it. -
Tarcisio José D at 08:35 AM on 28 October 2010What should we do about climate change?
Argus #45 "How about telling us more about what we really can and should do about climate change, in stead of this constant complaining about how skeptics ruin everything?" My answer: 1 - Spreading water in the Sahara desert. 2 - To preserve the forests. 3 - Reforest the deforested areas. 4 - Promote the research of soil that is waterproof. See Thermodinamics...... -
Paul D at 08:16 AM on 28 October 2010Skeptical Science Firefox Add-on: Send and receive climate info while you browse
Actually tried the same thing again and no side window appeared at all!??! I think you need a quick fix and release a new version (1.1). -
Paul D at 08:13 AM on 28 October 2010Skeptical Science Firefox Add-on: Send and receive climate info while you browse
Slight niggle (actually a big one). I searched for CO2, then clicked on the first subject. The side window popped up with the skeptic argument, I clicked on the SkS link and the page appeared in the tiny side window! pretty much undreadable unless you like side scrolling a lot. Would be better if it created a tab in Firefox and displayed the page in a full size window.Response: Okay, I've worked out what you mean and I hacked a solution (although Shine are working on a more robust solution for the next version of the Plugin). Thanks for the report. -
Peter Lang at 08:10 AM on 28 October 2010What should we do about climate change?
Marcus@29, you say: "Barry Brook, the cost estimates for Nuclear Power that you cite are based on the deliberate underestimates supplied by the nuclear industry itself." That statement is commonly made by the anti-nuclear people, the renewable energy advocates and the fossil fuel industry. But it is plainly wrong. You can find cost comparisons, (done on a properly comparable basis), by IEA, EIA, USDOE, EPRI, NEEDS and many other authoritative organisations. If anyone is propogating optimistic energy cost figures, with little integrity, it is the renewable industry. Have you seen the NEEDS studies? Look at the nuclear and solar thermal here for example: http://www.needs-project.org/index.php?option=com_content&task=view&id=42&Itemid=66 Notice that whereas the solar thermal analysis projected that the cost of solar thermal would drop by about 50% between 2007 and 2010, in actual fact the cost has increased by by 30% in the last year alone (ref: EPRI; and also EIA and USDOE) -
KeenOn350 at 07:58 AM on 28 October 2010Skeptical Science Firefox Add-on: Send and receive climate info while you browse
Sounds intriguing - but my browser of preference has been Opera, since before the days of Firefox. Not as well known, perhaps, but with the best browser security record, and lots of good features. Perhaps someone could do us an Opera widget for this? -
Brian D at 07:47 AM on 28 October 2010Skeptical Science Firefox Add-on: Send and receive climate info while you browse
Sweet! Added on, and I intend to make some use of it. I love Firefox, but switched to Chrome several months ago. I still keep Firefox around - mostly because of its incredible add-ons - but a Chrome extension would not go amiss. No idea if it's in the cards or not, though. I trust Shine Technologies' judgement here. -
muoncounter at 07:41 AM on 28 October 2010Measuring CO2 levels from the volcano at Mauna Loa
#21 "relative to inland stations like the one in Luxembourg." Andy, Nice job. The Massen and Beck paper is one of a number that conclusively demonstrate via experiment the anthro contribution to atmospheric CO2. Diurnal and seasonal patterns match traffic density: The last peak coincides with a NO maximum, sign of the Monday morning commuter traffic; the Monday CO2 peak exceeds the Sunday peak by about 40 ppm. Other authors (notably Idso 1998 and 2002) describe an urban 'CO2 dome' over major cities (in Idso's case, Phoenix, Arizona). It is quite stunning to see local CO2 concentrations touching 500-600 ppm at times when the MLO background was in the 360s. -
Philippe Chantreau at 07:40 AM on 28 October 2010The 2nd law of thermodynamics and the greenhouse effect
BP, I'm curious. Is it your personal opinion that the atmospheric greenhouse effect has been falsified indeed, as G&T or Kramm seem to argue? -
Kooiti Masuda at 07:35 AM on 28 October 2010Climate sensitivity is low
Maybe we discuss different things by the same term MEP (Maximum Entropy Production). I am not familiar with Swenson's theory, but as I browse abstracts shown at links by KR (#59), they seem to say too far-fetched things to be demonstrated by physical science (though they may be interesting philosophical thoughts). I do not think it helpful to discuss matters of physical science following Swenson's reasoning. What I remember by the key word "maximum entropy production" is something like the Wikipedia articles Non-equilibrium thermodynamics and Extremal principles in non-equilibrium thermodynamics mention by the key word. (Wikipedia may be rewritten. I mean the contents as of today.) I do not fully understand these theories, but I understand themes which some of these authors wanted to discuss. -
scaddenp at 07:34 AM on 28 October 2010What should we do about climate change?
Just on "I say a climate scientist who is actively publishing peer-reviewed papers on climate science." I'd agree but in Doran which I assume is the source of data, the 97% refers to "climate scientists publishing about climate change". The "climate experts" number would be 90%. I know its nit-picking but I think is helps the argument to get it correct. -
Argus at 07:31 AM on 28 October 2010What should we do about climate change?
This is interesting. This is the first blog post I have seen so far, among hundreds on this site, that actually begins to adress the important subject of 'What should we do about climate change?'. All the others seem to say, in many different ways, that our climate is heading towards a disaster, and that anyone who says otherwise is a humbug. Unfortunately, after four lines about using 'less energy', and turning to 'renewable energy', even this post went on into the usual raving about 'disinformation', 'propaganda', '97% of all scientists', 'conspiracy', etc. This post was a great disappointment. How about telling us more about what we really can and should do about climate change, in stead of this constant complaining about how skeptics ruin everything? -
mfripp at 07:14 AM on 28 October 2010Isn't global warming just 2 °C and isn't that really small?
The average temperature at the equator is about 30C. The average temperature at the North Pole is about -15C. If we assume that the temperature varies linearly with latitude, then the average temperature changes by 1C for every 2 degrees of latitude. If the Earth experiences a 6C temperature change, then this is the equivalent of Minnesota eventually having the weather of Louisiana which is 12 degrees of latitude to the south. Minnesota having the average weather of Louisiana is a big deal. And this is from the "best estimate" of a 6C temperature rise. If the estimate is wrong, then this could be larger. -
Daniel Bailey at 07:08 AM on 28 October 2010Skeptical Science Firefox Add-on: Send and receive climate info while you browse
Sweet, John! I look forward to using this! The YooperResponse: I look forward to you sending climate links to the database :-) -
Riccardo at 07:07 AM on 28 October 2010Climate sensitivity is low
Berényi Péter following your definition, the entropy production (EP) is determined by the temperature of the atmosphere at TOA (Ta), the temperature of the sun (Ts) and the earth albedo (α). Starting with the system in steady state, by suddenly increasing IR atmospheric absorption you're indeed lowering the EP via a reduction in Ta. Restoring steady state requires to increase Ta back to its original value and/or lowering the "incoming part" of EP through α. The latter alone would lead to a positive feedback which decreases Ta further. This is as far as we can get with this simple use of the MEP principle. We see the possibility of a negative feeback, which we already knew, and cannot rule out other positive feedbacks. Definitely more work need to be done in this field to obtain usefull insights from the use of the MEP principle in climate science. As of now, scientists are just looking at its range of validity mainly studying steady state situations, which presumably won't give new "practical" informations. Quoting Kooiti Masuda, "So MEP does not seem to me helpful as a piece of policy-relevant science of climate at present.". -
Kooiti Masuda at 07:02 AM on 28 October 2010The 2nd law of thermodynamics and the greenhouse effect
I admit that the sentence in the quotation marks in my comment shown as #96, "greenhouse effect contradicts the 2nd law of thermodynamics", is not a quote from Gerlich and Tscheuschner. I consider that the main subject of this thread is to discuss such a notion that may be expressed by the sentence I showed in the quotation marks. I think it is rather irrelevant whether it comes from Gerlich and Tscheuschner or not. -
Andy Skuce at 06:55 AM on 28 October 2010Measuring CO2 levels from the volcano at Mauna Loa
Arkadiusz: Thanks for those links. The paper by Massen and Beck contains the following figure, comparing CO2 readings for a station in Luxembourg and at Mauna Loa over the same four days in July, 2006.The graphs show the variations through the day at both stations, with the variations at Mauna Loa being much smaller. The dips in the afternoon readings on two of the days at Mauna Loa are probably due to upslope breezes bringing air from the lower reaches of the mountain that is slightly depleted in CO2 due to plant respiration. Note that the figure caption warns us that the scales are different.I digitized the two CO2 curves and plotted them at the same scale so that they can be directly compared, as shown below.
This illustrates how steady the Mauna Loa CO2 readings are relative to inland stations like the one in Luxembourg.
-
perseus at 06:35 AM on 28 October 2010What should we do about climate change?
The Ville at 20:58 PM on 27 October, 2010 Perseus, my own rather modest energy efficiency measures (like replacing my hot water tank with a continuous flow gas system, installing tinted windows & switching to compact fluorescent lights) has cut my electricity use *in half*-& led to only a marginal increase in my gas use. This means I've achieved a phenomenal reduction in my CO2 emissions-with no loss in my quality of life. One of the most effective means of reducing carbon for any individual is through various home improvements, particularily insulation, however this should really be standard construction nowadays. With respect to your case, to calculate the true saving in carbon you would have to calculate the amount of carbon required in manufacturing and installing these windows, similarily for the boiler and the lights. Moreover, to this you would have to add any carbon products purchased through whatever monetary saving you achieved through these measures. The main point however, is that although some of us in developed countries may be making some energy and carbon savings, how much are these measures more than offset by all those people in developing countries upgrading to a Western lifestyle? You are comparing a limited saving with an unlimited increase. -
Jesús Rosino at 06:31 AM on 28 October 2010Isn't global warming just 2 °C and isn't that really small?
Albatross #20, Regarding the "for how long" question, your paper is Solomon et al 2008: "climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop." And that's the crux of the problem: decisions must be taken before the impacts arise because there's no way back. Wait and see = too late. Cheers. -
Berényi Péter at 06:19 AM on 28 October 2010Climate sensitivity is low
#59 KR at 04:42 AM on 28 October, 2010 At most (if correct) it will affect the speed of climate convergence upon equilibrium when forcings change, not the final equilibrium. Dear KR, what you say, does not make sense. Until you learn to differentiate between thermodynamic equilibrium (isolated system, no entropy production) and steady state with energy flowing through the system and entropy produced by it at a constant rate, unfortunately we can't move a single step further. -
Berényi Péter at 05:57 AM on 28 October 2010The 2nd law of thermodynamics and the greenhouse effect
#101 KR at 03:46 AM on 28 October, 2010 Perhaps the clearest refutations of G&T come from Arthur Smith, "Proof of the Atmospheric Greenhouse Effect" (well worth reading) If we delve into arXiv.org, it should be read along with its counterpart. arXiv.org > physics > arXiv:0904.2767 Physics > Atmospheric and Oceanic Physics (physics.ao-ph) Cite as: arXiv:0904.2767v3 [physics.ao-ph] Comments on the "Proof of the atmospheric greenhouse effect" by Arthur P. Smith, arXiv:0802.4324 Gerhard Kramm, Ralph Dlugi & Michael Zelger "Smith's discussion of the infrared absorption in the atmosphere was scrutinized and evaluated. It was shown that his attempt to refute the criticism of Gerlich and Tscheuschner (2007, 2009) on the so-called greenhouse effect is rather fruitless." -
archiesteel at 05:40 AM on 28 October 2010The 2nd law of thermodynamics and the greenhouse effect
@nealjking: a brilliant explanation, thank you! I want more kangaroo-related metaphors. -
nealjking at 05:32 AM on 28 October 2010The 2nd law of thermodynamics and the greenhouse effect
#100, BP: "Since the measurable thermodynamic quantities of a voluminous medium, in particular the specific heat and the thermodynamic transport coefficients, naturally include the contribution from radiative interactions, we cannot expect that a change of concentration of a trace gas has any measurable effect" In that case, G&T would be "not expecting" wrong: change of concentration of a trace gas CAN have a measurable impact. I will write up a rebuttal of this error later, but briefly: The fact that the active agents of the greenhouse effect are an extreme minority of the atmosphere tells you absolutely nothing about the greenhouse efficacy of this minority. What matters is not the ratio of the number of greenhouse molecules to the total number of gas molecules, but the number of greenhouse molecules to the number of IR photons that are being blocked. As long as you have enough greenhouse molecules to catch the number of IR photons, you will have a greenhouse effect - pretty much regardless of the non-greenhouse molecules, which are incapable of interacting with the IR photons. In fact, to 1st order, if you increased the number of non-greenhouse gases by a factor of 10, so the trace GHG becomes 10 times "tracier", it would have NO EFFECT on the greenhouse capability of this minority. To 2nd order: the increase in the total amount of gas would increase the pressure of the atmosphere 10 times, resulting in pressure broadening of the IR absorption lines of the GHGs. So in fact, the GHGs would become even more efficacious, even as their relative concentration was reduced by 10. An analogy: You have a population of 10,000 people in a walled city, which is afflicted by invasions of kangaroos. So you hire 10 hunters to discourage the kangaroos. Do you ask, "10 hunters out of 10,000 people? That's only 0.1% ! How can 0.1% of the population protect against the kangaroos?" No, you don't, because the question is silly: What matters is not how many hunters there are relative to the population, but how many hunters there are relative to the number of kangaroos (and possibly, to the circumference of the walls). If there are 2 kangaroo intrusions per night, 10 hunters might be more than enough; if there are 100 kangaroo intrusions per night, probably not. In any case, it has NOTHING to do with the whether the population is 10,000 or 10,000,000. It would be an issue if we were talking about policemen trying to control crime among the populace: In that case, there would be an important difference between having 10 policemen for 10,000 people and 10 policemen for 10,000,000. But that is because policemen have to influence the populace, so their relative concentration is important. But the GHG molecules don't have to influence the non-GHG molecules: They just have to go after the IR photons. So the correct analogy is to the kangaroo hunters, and it doesn't matter how small a minority they are in the atmosphere. -
Climate sensitivity is low
To address some of what I might expect as a response to my last posting, I would like to note that if some mechanism (such as maximum entropy production, MEP) were operative in regards to thermodynamic equilibrium, it would certainly operate at all times. If it operated in the fashion described by Berényi, by increasing energy release to space and preventing temperature rises when GHG forcings would otherwise cause them to occur, it would operate at all times to maximize entropy, lowering the climate temperature as far as the system degrees of freedom allowed. TSI increases, for example, as seen in the early 20th century, would have no effect. Unfortunately for Berényi's formulation, it does. The 2nd law of thermodynamics sets the equilibrium (and yes, the steady-state) points, not an MEP effect, which is merely a constraint on how systems reach such states under the 2nd law. Climate sensitivity exhibits positive feedback. MEP cancellation of positive feedback is therefore prima facie incorrect; that emperor has no clothes. -
Daniel Bailey at 05:04 AM on 28 October 2010What should we do about climate change?
Re: transjasmine (37) I would augment the comments made by the others so far with this: from your first comment (and my reply to it) to your most recent, you have shown a lack of understanding of the subject matter you are commenting on. Did you learn anything from the pointing-in-the-right-direction I gave you? We are here to help those with questions, that's our role here. But when guidance is offered (by myself, JMurphy, KR and Phila), it is incumbent upon the person to whom it is given to then act upon it. Or to demonstrate, with supporting links, why it is wrong. It is expected that you will still have questions, certainly. And please do ask them. But to keep the moderators happy (☻), try to find an appropriate thread for them. There is always room for one more honest learner at this banquet table. The Yooper -
Philippe Chantreau at 04:49 AM on 28 October 2010The 2nd law of thermodynamics and the greenhouse effect
The eternal story of climate "skepticism." Such nonsense as G&T does not have to be really peer-reviewed but the refutation has to be, despite the obvious nonsense. When was that double standard established? What justifies it? -
Climate sensitivity is low
Berényi - I did read what you wrote, ad hominem responses on your part not-withstanding. There is considerable evidence for positive feedback in climate sensitivity, and none for the "no positive feedbacks" claim you have made. In fact, the MEP is inappropriate when discussing the final destination in thermodynamics. "A system will select the path or assemblage of paths out of available paths that minimizes the potential or maximizes the entropy at the fastest rate given the constraints" (Swenson, R. 1989). This means that the MEP principle will "select the pathway or assembly of pathways that minimizes the potential or maximizes the entropy at the fastest rate given the constraints" (Swenson, R. and Turvey, M.T. 1991), emphasis added. The Second Law indicates that systems act to minimize potential/maximize entropy. It does not say by what path. MEP is an additional constraint on the 2nd law, not a replacement thereof. At most (if correct) it will affect the speed of climate convergence upon equilibrium when forcings change, not the final equilibrium. To quote Christopher Hitchens: "That which can be asserted without evidence, can be dismissed without evidence." MEP certainly qualifies in regards to climate sensitivity. -
archiesteel at 04:21 AM on 28 October 2010Isn't global warming just 2 °C and isn't that really small?
@ClimateWatcher: "my analysis supports a best-estimate 2XCO2 climate sensitivity of 1.7 deg. C" I believe that's not including feedbacks. "There is not a great deal of evidence of net positive feedback taking place" That's your opinion, but it is not supported by evidence. The role of Water Vapor as a feedback mechanism is quite well understood, as well as the fact that warming oceans will release additional CO2 in the atmosphere. "Also, the Eemian and Holocene Climatic Optimum temperatures (~ 6000 ya, ~120,000 ya ) exceeded current temperatures." Indeed, but not by much - we should go above these temperatures much before 2100 (we are already at temps rivaling the HCO). Consider what sea levels were in those times to get an idea of what might be in store for us. Not fun. "The IPCC best estimate for the low scenario is 1.8 °C" The "low scenario" is unlikely, considering we are still pouring gigatons of CO2 in the atmosphere at a record rate. I think you're being overly optimistic, here. The best survival strategy is still "hope for the best, prepare for the worst." Since "preparing for the worst" entails moving away from fossil fuels - soemthing we need to do for a lot of other reasons - your optimism seems unwise, from an existential point of view... -
Berényi Péter at 04:17 AM on 28 October 2010Climate sensitivity is low
#57 KR at 01:44 AM on 28 October, 2010 If MEP is a factor, it's always been a factor, and can be considered to be included in measured climate sensitivity No, it is not that simple. Please try to understand what was said before you venture in. You would make me happy if just once you could abandon the holistic approach and concentrate on the problem at hand with an analytical mind. This kind of thinking, although requires some discipline, is surprisingly effective and is much more in line with our own cultural heritage.Moderator Response: BP, out of respect to KR and his reply to this I won't delete this, but please try to be less adversarial in the future. Disagree, certainly, but keep it cordial. -
ClimateWatcher at 03:56 AM on 28 October 2010Isn't global warming just 2 °C and isn't that really small?
"Finally, 6 °C, the actual “best estimate” for eventual global warming from current CO2 trends still sounds small." The IPCC best estimate for the low scenario is 1.8 °C and even that exceeds the thirty year trends. The best estimate is not 6 °C.
Prev 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 Next