Recent Comments

Prev  1116  1117  1118  1119  1120  1121  1122  1123  1124  1125  1126  1127  1128  1129  1130  1131  Next

Comments 56151 to 56200:

56151. sauerj at 12:20 PM on 27 July 2012
       Tar Sands Oil - An Environmental Disaster
       See page 3, paragraph 8 (of McKibben's article) for this 240 gigaton value.
56152. sauerj at 12:19 PM on 27 July 2012
       Tar Sands Oil - An Environmental Disaster
       Similar question as mandas: Bill McKibben's Rolling Stone article says Canadian Tar Sands contain 240 gigatons of carbon (half the 2C budget; sure got my attention). This article says 1 gigatonne (billion tonnes). Huge difference. What am I missing here???
56153. Bernard J. at 11:51 AM on 27 July 2012
       2nd law of thermodynamics contradicts greenhouse theory
       A note to the unwary. 'Silas' is Girma Orssengo, who has in the past displayed an astonishingly blinkered misunderstanding of science. Arguing with this ardent Ayn Rand acolyte will get one nowhere, very fast. On the matter of the claim that 'cool' cannot radiate to 'warm', I'd invite Silas/Orssengo to visit http://scienceblogs.com/deltoid/2012/05/17/tim-curtins-incompetence-with/ where such nonsense might be kicked around the park, as was done with Tim Curtin, and thus save clogging the thread here. And as Orssengo is apparently a functioning engineer, I would invite him to explain somewhere in his discourse how energy moves through the lumen* of a Dyson sphere. [*Yes, it was deliberate...]
56154. Sabretruthtiger at 09:57 AM on 27 July 2012
       It's the sun
       (snip)
       Moderator Response: TC: Sabretruthtiger, your post is a gish gallop of off topic claims and bald assertions, none of it backed by evidence from the peer reviewed literature or other reliable source. As such it constituted sloganeering. It contributes nothing more to the discussion than simply typing "You are all wrong" would have. Sloganeering is forbidden by the comments policy. I recommend you read it, and comply with it in future.
56155. Tom Curtis at 09:29 AM on 27 July 2012
       2nd law of thermodynamics contradicts greenhouse theory
       Silas, you wrote:

       "You are confusing radiation (electromagnetic waves) with creation of thermal energy (heat). Heat is a process involving transfer of energy based on temperature - as opposed to generic radiation of photons. It follows that thermal radiation (a process creating heat) from a cold to a hot body (i.e. from the atmosphere to the Earth) is a physical impossibility."

       It is difficult to interpret this in any other way than a prediction that there is no thermal (IR) radiation originating in the atmosphere and being absorbed by the Earth's surface. I like that. It is a risky prediction that is easily checked by empirical means. You later write:

       "It is incumbant upon proponents of the GHE to demonstrate their theory through ... prediction of events in nature"

       Presumably you therefore think it is incumbent on you, since you have made a risky prediction to actually check the data to see if your risky prediction is verified, or falsified by the data. Fortunately, climate scientists believe the same thing. They have predicted the existence of downward IR radiation from the atmosphere, and have checked. Indeed, here is a comparison of some of their predictions with observations: (Source) I don't want you to notice the very good correlation between AGW predicted and observed Downward IR Radiation. I want you to notice that the downward IR radiation exists, in direct contradiction of your prediction. If you follow the link to the source of the diagram (Science of Doom), you will find many other examples of observations of this radiation you claim cannot exist. Indeed, even the noted "skeptic" Roy Spencer is not so foolish as to deny the existence of downward IR radiation (back radiation). In fact, he has measured it himself:

       "For instance, last night I drove around pointing this thing straight up though my sunroof at a cloud-free sky. I live in hilly territory, the ambient air temperature was about 81 F, and at my house (an elevation of 1,000 feet), I was reading about 34 deg. F for an effective sky temperature. If the device was perfectly calibrated, and there was NO greenhouse effect, it would measure an effective sky temperature near absolute zero (-460 deg. F) rather than +34 deg. F, and nighttime cooling of the surface would have been so strong that everything would be frozen by morning. Not very likely in Alabama in August. What was amazing was that driving down in elevation from my house caused the sky temperature reading to increase by about 3 deg. F for a 300 foot drop in elevation. My car thermometer was showing virtually no change. This pattern was repeated as I went up and down hills. The IR thermometer was measuring different strengths of the greenhouse effect, by definition the warming of a surface by downward IR emission by greenhouse gases in the sky. This reduces the rate of cooling of the Earth’s surface (and lower atmosphere) to space, and makes the surface warmer than it otherwise would be."

       (Source, this link should not be interpreted in any way as agreement with Spencer's views on other subjects.) So, to the extent that you have predicted that there is no back radiation, you are wrong. Perhaps you would like to show your commitment to the principles of science by stating clearly that you are wrong. If you are willing to do so, we may be able to progress in resolving your conundrum.
56156. KR at 09:05 AM on 27 July 2012
       2nd law of thermodynamics contradicts greenhouse theory
       Silas - I think one of the best summaries of the G&T paper comes from Gavin Schmidt, who had some of the same reactions to it that I did:

       It's garbage. A ragbag of irrelevant physics strung together incoherently. For instance, apparently energy balance diagrams are wrong because they don't look like Feynman diagrams and GCMs are wrong because they don't solve Maxwell's equations. Not even the most hardened contrarians are pushing this one....

56157. Tom Curtis at 08:56 AM on 27 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Chris Machens @30, in addition to my immediately preceding comment, I note that the error in reporting of fossil fuel production is +/- 6% according to one recent report (an improvement on the +/- 10% reported in Margate. That uncertainty passes on to calculations of the depletion of O2. Consequently, discovery of source of O2 depletion not included in IPCC calculations that is less than 0.74% of the calculated value will not change the estimate within error.
56158. dana1981 at 08:38 AM on 27 July 2012
       Tar Sands Oil - An Environmental Disaster
       Thanks michael, that should have been 65,000 gallons. Text corrected.
56159. Tom Curtis at 07:55 AM on 27 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Ian Forrester @31, methane released by anaerobic bacteria in land fills will decay in the atmosphere based on the chemical formula: CH4 + 2 x O2 => CO2 + 2 x H2O Therefore, typically, each methane molecule released by landfill (or any other source) will deplete the atmosphere of two oxygen molecules. What Chris Machens @31 is neglecting is that carbon in landfill comes essentially from only two sources - fossil fuels either as some form of oil or fuel, or converted into plastics; and biomass in the form of kitchen and garden scraps, or wood, cotton, or wool. Taking the carbon sourced from biomass first, because that carbon was taken from the atmosphere by photosynthesis, in a process that releases oxygen. In fact, photosynthesis in plants follows the formula: 6 x CO2 + 6 x H2O => C6H12O6 + 6 x O2 showing a deficit of 1 O2 molecule for each carbon atom fixed compared to the equation for the oxidation of methane. However, the process of converting sugar to methane will release an additional net 3 O2 molecules, and gaining the additional two hydrogen atoms, presumably from water, will release yet more oxygen. The net effect on atmospheric O2 levels is neutral. Carbon from fossil fuels is slightly different. In calculating CO2 emissions from fossil fuels, scientists do allow for those fuels turned into stable products such as plastics, which do not decay easily and hence do not release their carbon to the atmosphere. According to Margate et al (1984) They represent about 6.7% of all liquid fossil fuels, and 3.2% of gases. However, relatively volatile products are already included in the accounting, and hence are not a source of additional O2 loss. And the non-volatile products such as plastics do not typically decay, and hence are not the source of methane from land fill. Hence, while some small amount of the methane generated in land fill may not be accounted for in determining the expected O2 loss from fossil fuels, the effect is likely to be very small. It is certainly likely to be smaller than the approximately 10% error margin in estimates of fossil fuel production (Margate et al) and hence of O2 depletion.
56160. michael sweet at 07:37 AM on 27 July 2012
       Tar Sands Oil - An Environmental Disaster
       Dana, Another excellent post. It is hard to see the advantages of this type of energy. One of your links says "230,000 liters(600,000 gallons)" one of these numbers is wrong.
56161. KR at 07:25 AM on 27 July 2012
       2nd law of thermodynamics contradicts greenhouse theory
       Silas - I would strongly recommend you read through some of the posts referred to above, some of the >1400 comments on this thread, actual reviews of what G&T presented - before deciding that all the people who have looked at the G&T claims are idiots. Science of Doom in particular is sourced by a physicist - and you seem to have prejudged his expertise. I would also point you to the Real Climate collection on this, which links to various commentaries and a peer reviewed comment - all rebutting the G&T nonsense. You might also look at Dr. Fred Singer's (a rather notorious skeptic of just about anything - ozone holes, 2nd hand smoking, climate change) characterizing 2nd Law objections as unsupportable and embarrassing 'denial'. "It is incumbant upon proponents of the GHE..." No, it is not; that work has already been done. The radiative greenhouse effect is supported by multiple lines of evidence, physics, observations, etc. G&T (and you, apparently) feel that all this data is incorrect - that's an extraordinary claim, and requires evidence supporting that isolated view to be taken seriously. The burden of (dis)proof is on you.
56162. scaddenp at 07:14 AM on 27 July 2012
       2nd law of thermodynamics contradicts greenhouse theory
       Silas, then can I suggest then that you read the Science of Doom articles to which you have been pointed to and if that is unconvincing, then try the physics textbooks from which the author draws his points? There is nothing contradicting basic physics/thermodynamics here, just a misunderstanding of the physics at work. If G&T were right, then how would explain the MEASURED back-radiation at the surface or the drop in the energy band as measured at the TOA? (among the many experimental confirmations of normal physical theory). The experimental evidence is with conventional physical theory, not with G&Ts strange interpretation of LTE. You might also like to check out AP Smith rebuttal here.
56163. Silas at 07:03 AM on 27 July 2012
       2nd law of thermodynamics contradicts greenhouse theory
       @Composer99 at 05:27 AM on 27 July, 2012 I have read the G&T paper and have a background in engineering thermodynamics. It is incumbant upon proponents of the GHE to demonstrate their theory through (-Snip-) prediction of events in nature - i.e. unexpected and cataclysmic consequences of global warming. Confirmations do not count in science as such 'evidence' is always easy to find. (-Snip-) (-Snip-)
       Moderator Response: [DB] Multiple examples of unsupported sloganeering snipped.
56164. Ian Forrester at 06:51 AM on 27 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Chris Machens asks:

       What about methanogenesis from landfills, which depletes oxygen?

       Just how do methanogenic bacteria deplete oxygen? They are strict anaerobes i.e. they grow in the complete absence of oxygen. Most landfills go to great extremes to compact the garbage so that there is very little air space left. Aerobic micro-organisms exhaust this very low amount of oxygen so that the anaerobes can take over. Thus landfills are not responsible for oxygen depletion. Why are you trying to connect all those fringe processes as culprits for oxygen depletion when the gorilla in the room is the burning of fossil fuels?
56165. Silas at 06:50 AM on 27 July 2012
       2nd law of thermodynamics contradicts greenhouse theory
       KR at 05:24 AM on 24 November, 2010 Heat flow is the unidirectional and is based upon the need for thermal equilibrium between bodies. Extremely basic physics. It is a process not a summation and therefore cannot be "negative" - an egregious nonsense. (-Snip-)
       Moderator Response:

       [DB] Please familiarize yourself with this site's Comments Policy before composing future comments.

       Egregious inflammatory snipped.

56166. KR at 06:03 AM on 27 July 2012
       2nd law of thermodynamics contradicts greenhouse theory
       Silas - I would suggest, as Composer99 recommended, to look at the Science of Doom site (search there for "Gerlich"), including such gems as On the Miseducation of the Uninformed by Gerlich and Tscheuschner (2009) and Radiation Basics and the Imaginary Second Law of Thermodynamics. Quite frankly, I cannot think of another paper in the field that has been so definitively and repeatedly shown to be dreck. G&T's work is absolutely horrible...
56167. Composer99 at 05:27 AM on 27 July 2012
       2nd law of thermodynamics contradicts greenhouse theory
       Not this again! Silas: There is an enormous body of theoretical, experimental, and most importantly empirical evidence showing that the atmospheric greenhouse effect, however misnamed, is fact. It does not violate any law of thermodynamics, it does not allow any sort of perpetual motion machine. Gerlich & Tscheuschner are, simply put, wrong, wrong, wrong. For more in-depth information you can check out the blog Science of Doom which has some reviews of the G&T paper here. You can also check out some other important Science of Doom posts regarding the relevant physics here and here. Science of Doom relies heavily on the actual maths of the situation and basic radiative physics known for decades.
       Moderator Response: [DB] In addition to the valuable links provided by Composer99 above, please see this SkS post, Has the greenhouse effect been falsified?.
56168. Silas at 03:52 AM on 27 July 2012
       2nd law of thermodynamics contradicts greenhouse theory
       @ RW1 at 11:08 AM on 16 December, 2011 "There is no violation of the second law with the Greenhouse Effect, because it's not about energy going from cold to warm through a conduction process." You are confusing radiation (electromagnetic waves) with creation of thermal energy (heat). Heat is a process involving transfer of energy based on temperature - as opposed to generic radiation of photons. It follows that thermal radiation (a process creating heat) from a cold to a hot body (i.e. from the atmosphere to the Earth) is a physical impossibility. The Second Law prevents this because otherwise it would be possible to obtain work from transfer of heat into the atmosphere; i.e power station cooling towers. Essentially, we could then reuse the energy and build a perpetual motion machine. AGW is predicated on a misunderstanding of the Second Law which is thoroughly debunked by eminent German physicists (as opposed to climate scientists who are generally not professional physicists) Gerlich and Tscheuschner.
       Moderator Response: TC: Link to RW1's post added.
56169. Composer99 at 03:45 AM on 27 July 2012
       Hurricanes aren't linked to global warming
       David: In addition to the comments by Dikran and DSL, I should like to note that the additional energy in the system resulting from greenhouse warming is not evenly distributed, temporally or spatially. As such the potential exists for larger gradients leading to more intense storm activity, as suggested by the Intermediate version of this article and comment #47 (although as per that comment and the IPCC SREX more research is needed to confirm whether this is occuring).
56170. vrooomie at 03:32 AM on 27 July 2012
       New research special - satellite measurement papers 2010-2011
       ModResponse@5: Sorry, I was just showing off my *mad skills* by hot linking the already-extant unhot link in Comment 2...that's what I get for being helpful...;)
56171. Lanfear at 03:10 AM on 27 July 2012
       New research special - satellite measurement papers 2010-2011
       Re: Record Greenland Ice Melt To be fair, it should be highlighted that this seems to be a cyclical thing (why?) which they also mention in the article itself, so the event as such is not that interesting. What is interesting is, what has caused it, and will the trend change. Maybe this is linked to what the Mernild et al. (2011)-paper describes?
56172. DSL at 01:26 AM on 27 July 2012
       Earth hasn't warmed as much as expected
       Maybe they're making an example of Lindzen. I'd hate to think they're being "fair and balanced" in representing the science. The climate security material on the Sandia website seems like they get it.
56173. DSL at 01:20 AM on 27 July 2012
       Hurricanes aren't linked to global warming
       So, David, if a difference exists "normally," then adding more to one side of the equation wouldn't produce a greater difference? The vertical profile of GHE warming is not uniform. The lower troposphere is warming at a greater rate than the upper troposphere. According to your understanding, would that not create a greater temp difference? lower trop = 0.134 K/decade mid-trop = 0.079 K/decade tropopause = -0.011 K/decade lower strat = -0.302 K/decade That's a simplistic answer, but your response was simplistic. This is not a simple box model we're dealing with. Tropical convection doesn't occur absent of other large-scale forces (increased available water vapor, for example). I'm also thinking you didn't click on the "intermediate" tab above.
56174. Dikran Marsupial at 01:09 AM on 27 July 2012
       Hurricanes aren't linked to global warming
       David Friedman The observation you are commenting on does not imply any sort of perpetual motion machine as the energy that drives the heat engine is ultimately provided externally by the sun. However global warming makes more of the Sun's energy available for the creation and intensification of storms. If the Earth were thermodynamically a closed system, then your argument would have some merit, but it isn't. I would suggest that it is a good idea to refrain from suggeting that others don't understand the science, it is generally better to adopt some humilty and assume that it is you that is wrong, and ask for an explanation of why your objection is incorrect.
56175. David Friedman at 00:59 AM on 27 July 2012
       Hurricanes aren't linked to global warming
       You write: "The background to these enquiries stems from a simple observation: extra heat in the air or the oceans is a form of energy, and storms are driven by such energy. What we do not know is whether we might see more storms as a result of extra energy or, as other researchers believe, the storms may grow more intense, but the number might actually diminish." That sounds plausible, but it is wrong,as should be clear to anyone familiar with basic thermodynamics. A storm is a heat engine--it converts thermal energy into mechanical energy (in the form of winds). A heat engine that converts all the thermal energy it takes in to mechanical energy is what is known as a perpetual motion machine of the second kind. It is impossible because it violates the second law of thermodynamics (entropy), in contrast to a perpetual motion machine of the first kind, which violates the first law (energy conservation). The standard example would be a ship that needed no fuel, because it ran off the heat of the ocean. Actual heat engines absorb thermal energy from a hot source, convert some into mechanical energy, and dump the rest into a colder sink. What determines the amount of mechanical energy they get is not the temperature of the source but the temperature difference between source and sink. So simply raising the temperature of sea and air doesn't make more energy available. You need some mechanism that raises the temperature difference. Hence the argument you offer is wrong (whether the conclusion is wrong I don't know). Either you don't understand the relevant science or you are willing to misrepresent the science in order to provide a simple argument for your conclusion. Your site is supposed to be offering accurate scientific information--the fact that it makes an argument inconsistent with elementary thermodynamics is a reason not to trust other arguments it makes. Sources of information that can be trusted on politically contentious issues are rare and valuable. I'll check back in a few days to see if you are still making the same argument. If you are, you are not such a source.
56176. chriskoz at 18:07 PM on 26 July 2012
       Tar Sands Oil - An Environmental Disaster
       Tom in QLD or Mr Keystone in AB, all can rightly claim that their share of emissions is "not disastrous". Classic tragedy of the Commons, like Great Stink of London in mid-1800. I'm amazed that people still did not learn anything from that event and after 150y+ still denying (e.g. more than half of REPs in US) the stink.
56177. prokaroytes at 17:21 PM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       One last input from my site here. What about methanogenesis from landfills, which depletes oxygen? And what is statistical significant, what are we looking for exactly to explain the O2 depletion?
56178. trunkmonkey at 15:33 PM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       "It is important to note that because the fall in O2 concentration is significantly less than that predicted from known combustion of fossil fuels, the uptake of CO2 by photosynthesis must exceed the combustion or decay of modern organic material from either anthropogenic (Land Use Changes) or natural sources." (Off topic snipped)
       Moderator Response: TC: Trunkmonkey, the effect on CO2 on plants is not a subject of this post and consequently, this post is off topic. If you wish to raise a particular point about that subject, or if anyone wishes to respond to this post, you can do so where the discussion is on topic.
56179. dana1981 at 14:51 PM on 26 July 2012
       Earth hasn't warmed as much as expected
       Well, I see that Sandia issued a press release for at least one of their other climate talks (a good one), so maybe it's just their standard practice, and perhaps it took them a while to summarize Lindzen's talk. So perhaps the press release isn't quite as bad as I initially thought.
56180. Tom Curtis at 14:05 PM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Chris Machen @27, Wikipedia lists total methane emissions of 600 teragrams per annum, or 600 million tonnes of methane per annum; and 20 terragrams (million tonnes) increment after sinks are taken into account. Compared to the 2008 fossil fuel plus cement emissions of That is less than the 720 million tonnes 8750 million tonnes, that still only represents 7% for total emissions, or 0.2% for net emissions. Of those emissions, those from wetlands (225 Tg/a), termites (20 Tg/a), ruminants (115 Tg/a), waste treatment (25 Tg/a) and biomass burning (40 Tg/a) are all generated from carbon originally removed from the atmosphere by photosynthesis in recent times. As such, the full cycle involves no net change in O2 levels. A further 110 Tg/a comes from fugitive emissions from the fossil fuel industry, and hence are already accounted for as part of total human emissions from fossil fuels. That leaves just 65 of 600 Tg/a that can make an additional contribution to the reduction of O2 levels in the atmosphere. That represents an additional 0.74% O2 reduction from methane emissions. Thus calculated, I can concede the amount is greater than 0.2% - but I certainly cannot see how it could be considered significant. I should note, however, that only clathrates represent emissions of methane which do not derive their carbon from either recent photosynthesis (hence having no net effect) or from fossil fuels (hence already accounted for). Clathrates represent 0.11% of the effect of fossil fuels based on the wikipedia figures.
56181. SteveS at 12:32 PM on 26 July 2012
       Earth hasn't warmed as much as expected
       I don't recall hearing that he was coming out here. I was on vacation most of June, so I must have missed the talk - I don't even recall seeing an announcement that he was coming. It's rather disappointing that he would've been allowed a venue at SNL given his recent record, especially after having Dr. Santer out (I think last year). But this is a pretty conservative institution with lots of engineers, so I can see it happening.
56182. Albatross at 12:27 PM on 26 July 2012
       Earth hasn't warmed as much as expected
       Hi Dana, Oh dear, Sandia has a lot of explaining to do, because now they are guilty of promulgating misinformation. Worse, it shows that they were uncritical of Lindzen's claims and opinions. I mean for goodness' sakes-- Sandia labs is affiliated with Lockheed Martin and the U.S. Department of Energy’s National Nuclear Security Administration. How on earth can these organizations, organizations who rely so critically on accuracy and robustness, endorse Lindzen's litany of fallacies and misinformation?
56183. dana1981 at 12:19 PM on 26 July 2012
       Earth hasn't warmed as much as expected
       Albatross - even worse, Sandia issued a press release with Lindzen's misinformation, for some reason a month after the talk happened. That press release was then picked up and Lindzen's misinformation was spread throughout the interwebs to a much larger audience. Inviting Lindzen to talk was a big enough mistake, but then to issue a press release about it? A month after the fact? Bad move, Sandia.
56184. prokaroytes at 12:14 PM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Thanks for your input everybody. Though what i meant basically was what Tom points out to me in 26. I checked wiki again and found this "Uncontrolled build-up of methane in Earth's atmosphere is naturally checked—although human influence can upset this natural regulation—by methane's reaction with hydroxyl radicals formed from singlet oxygen atoms and with water vapor." With ozone depletion causes oxygen depletion is the result from the methane -> water vapor - reaction, and then the water vapor in the cold stratosphere destroys ozone. So maybe the ozone destruction doesn't destroy oxygen but it happens before that. However the above quote is from this page http://en.wikipedia.org/wiki/Atmospheric_methane which shows also (Section "Emissions accounting of methane" 1999 numbers?)about a 60 : 40 ratio for anthropogenic contribution to methane sources. (notice rice paddies are listed under natural sources) Emissions + Sinks Imbalance (trend)+20 ~2.78 Tg/(nmol/mol) +7.19 (nmol/mol)/a And further down (Section "Rice agriculture") "crop alone is responsible for approximately 50-100 million metric tons of methane emission each year" So i think the emission of methane are higher than 0.2%. However i do not meant to say this is the only source, just another - and possibly above 0.2%.
56185. Albatross at 11:53 AM on 26 July 2012
       Earth hasn't warmed as much as expected
       Unbelievable that Sandia National Labs would even consider entertaining the misinformation from Lindzen or associating themselves with Lindzen who is known for promulgating misinformation. Lindzen's egregious errors and misinformation have been pointed out so many times now, here at SkS and elsewhere, and what does he do? Lindzen simply recycles the same errors and misinformation-- this time to "Sandia National Labs"-- knowing full well that the information in his talks is incorrect and/or misleading. Talk about bringing MIT into disrepute.... Frankly, I find such behaviour by an academic, from MIT of all places, to be horrendous and unacceptable. Dr. Mike Mann was (needlessly) investigated by PSU based on nothing but false allegations and innuendo, he was of course vindicated. Why is Lindzen not being held accountable by MIT when the evidence against him of misconduct is incontrovertible?
56186. dana1981 at 11:00 AM on 26 July 2012
       Earth hasn't warmed as much as expected
       We're working on a response to that horrid talk, KR. Look for it next week.
56187. Tom Curtis at 09:41 AM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Chris Machens @13 raises an interesting question. Unfortunately he then diverts into a side issue with a discussion of Ozone, which is essentially irrelevant. All we need to recognize is that methane released to the atmosphere will eventually break down to a CO2 molecule and two H2O molecules, consuming two O2 molecules in the process. As CO2 and H2O are the most chemically stable products of the various reaction pathways between CH4 and O2, we can ignore the details. The question then arises, how significant is the release of methane to the depletion in atmospheric O2? Total methane emissions have raised the methane concentration in the atmosphere by approximately 250 parts per billion since 1978. Given that the atmosphere contains approx 1.8 * 10^20 moles, and the molar mass of methane is 16 grams per mole, that represents emissions of 720 million tonnes of methane. Over approximately the same period, humans have used for energy, or flared over 350,000 million tonnes of methane. Thus emissions of methane represent just 0.2% of human consumption of methane. The figures used are conservative, and do not include the fact that much of the methane emission comes from fugutive emissions (gas leaks) from human energy use which are incorporated in the total human consumption. So, while Chris has identified a genuine additional source of O2 depletion, it is too small relative to human use of gas for energy to be noticeable within error; let alone compared to the total use of fossil fuels, of which gas is a very minor component.
56188. Tom Curtis at 08:56 AM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Chris Machens @23, to give your quote in context, it reads as follows:

       "4.2.3 HOX catalytic cycles -- The importance of these two species, methane and water vapor, in ozone chemistry is that they transport and release hydrogen into the stratosphere. The activated hydrogen that is released can then participate in the destruction of odd oxygen, i.e., ozone, through a variety of catalytic cycles. These reactive hydrogen (HOX) cycles are summarized by Figure 5.15. The open circles show the predominant species in which hydrogen exists in the stratosphere. We have not included H2 (molecular hydrogen), H2O (water vapor), and CH4 (methane) since they are not involved in the fast stratospheric hydrogen photochemistry balance. The arrows with superimposed boxes are reaction pathways. For example, OH (left circle) reacts with O3 to form HO2. The reaction is written OH + O3 --> HO2 + O2 On the figure, we see this represented by the line with the superimposed blue (O, O3) box. The O2 (molecular oxygen) product is not represented, because it is not a hydrogen species. All of the reactions which lead to ozone creation are colored in blue, while ozone photolysis is colored in magenta. Each water vapor molecule can be transformed into two molecules of HOX (reactive hydrogen) through reaction with O atoms via a reaction of water vapor with the singlet D oxygen atom. H2O + O(1D) --> 2 OH Recall that HOX = OH + HO2. In this case, the reactive hydrogen exists in the form of two liberated OH (hydroxyl radical) molecules which become the catalyst in a pair of reactions with odd oxygen (OX) that result in a net loss of OX, by which we mean a net loss of both ozone molecules and free oxygen atoms. OH + O3 --> HO2 + O2 HO2 + O --> OH + O2 ------------------------- NET: O3 + O --> 2 O2 (See Figure 5.15a) Notice that the NET effect of the reactions is simply a conversion of two odd oxygen molecules into two molecules of O2. The sum of reactive hydrogen, OH + HO2, is conserved by this cycle."

       (Your quote underlined; my bolding) So, in context it is clear that the net reaction to which your refer is the loss of O3 and O and the creation of O2, hardly an explanation for the depletion of O2 from the atmosphere. That section, however, does not refer to section 4.2.2 from which you draw the methane related reactions, so I am unsure why you refer to it, or why Phil drew attention to it.
56189. Bob Loblaw at 08:53 AM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       OK. Chris. Let's see: 1) ozone is O3 2) "free oxygen atoms" = O Is there anything we've forgotten? Perhaps O2, commonly referred to as "oxygen"? Does the statement "O3 + O ==> 2O2" show up somewhere?
56190. Andy Skuce at 08:45 AM on 26 July 2012
       Tar Sands Oil - An Environmental Disaster
       Clyde@5 In his recent New York Times article, I think that James Hansen's figures for the increase of atmospheric CO2 as a result of complete exploitation of the tar sands are incorrect. He cites a figure of 240 Gt of carbon in the tar sands, which, once combusted, would produce an increase of 120 ppm in the atmospheric concentration of CO2. This assumes that the atmospheric fraction (the percentage of CO2 emitted that stays in the air) would be 100% (today it's about 45%, with the rest of the CO2 going into the ocean and biosphere). Although some people are worried that the atmospheric fraction may increase over the next few decades as the biosphere turns from source to sink, it is very unlikely to rise to 100%. On the other hand, Hansen believes that we have already put too much extra CO2 into the ocean-atmosphere system and that we will have to, some day soon, take it out and sequester it. In that case, using the 100% figure is appropriate for the amount of CO2 that we will have to extract. The 240GtC figure he quoted in the NYT (last year in the Huffington Post he used a figure of 400GtC) is derived from the total bitumen-in-place, not the recoverable bitumen. Current recovery rates are around 50% for the most suitable reservoirs that have been chosen to exploited first and it seems unlikely, even with great improvements in technology, that the recovery rate for the unproven resources, which are located in thinner, deeper or less porous rocks, will exceed 50%. I would say that the 120ppm figure is too high by a factor of two and maybe even a factor of four. Which does not mean that I think developing the tar sands is inconsequential for the climate. On the contrary, an addition of 30-60ppm of CO2 from a single source is a very significant contribution towards the climate disaster that we are busy creating.See my blogpost Alberta’s bitumen sands: “negligible” climate effects, or the “biggest carbon bomb on the planet”? for more detail.
56191. prokaroytes at 08:05 AM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       I read following this section "In this case, the reactive hydrogen exists in the form of two liberated OH (hydroxyl radical) molecules which become the catalyst in a pair of reactions with odd oxygen (OX) that result in a net loss of OX, by which we mean a net loss of both ozone molecules and free oxygen atoms." Soooo? "..net loss"
56192. Flakmeister at 08:04 AM on 26 July 2012
       2012 SkS Weekly Digest #29
       Not sure where this should go but your Braganza et al 2004 link is dead in http://www.skepticalscience.com/Empirically-observed-fingerprints-of-anthropogenic-global-warming.html replace it with http://150.229.66.66/staff/jma/2004GL019998.pdf
56193. Phil at 07:55 AM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Chris Machens, You also need to read section 4.2.3 of the document you linked to.
56194. prokaroytes at 07:33 AM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Phil "methane water vapor oxygen depletion atmosphere" This article describes the chemical reaction better: methane reacting with something called the singlet D oxygen atom, denoted O(1D). This is a free oxygen atom that is in a particular sort of excited state. The reaction is CH4 + O(1D) --> CH3 + OH The result is a hydroxyl radical and a leftover methyl radical (CH3), which quickly reacts via CH3 + O2 + M --> CH3O2 + M CH3O2 + NO --> CH3O + NO2 CH3O + O2 --> HCHO + HO2 Eventually, reactions of HCHO (formaldehyde) with the hydroxyl radical result in the production of another water vapor molecule in the region between 35 and 45-km HCHO + OH --> CHO + H2O http://www.ccpo.odu.edu/~lizsmith/SEES/ozone/class/Chap_5/5_4.htm
       Moderator Response: TC: Link made live.
56195. Tom Curtis at 07:23 AM on 26 July 2012
       Tar Sands Oil - An Environmental Disaster
       Further to Dana @6, Hansen is on record as saying that one way to tackle global warming is to never build another coal fired power station, and to phase out all existing coal stations by the end of their design life. He also adds a simultaneous fee and per capita dividend carbon tax. The idea is that by preventing the use of all coal reserves we prevent the burning of sufficient fossil fuels to exceed the 1.5 degree C limit he considers to be the safe limit on temperature increase. Clearly, following this logic he would oppose the opening of new coal mines in my home state of Queensland (Australia), even though all Qld reverves by themselves are no where near enough to take us over that limit. The logic is that what we (Queenslanders) permit ourselves to do, we cannot object to in others; and if others equally exploit their coal reserves we are heading for a 5 degree plus world. The same logic applies to tar sands. Even if the Alberta tar sands are not by themselves enough to bring on disaster, exploiting them tacitly encourages the exploitation of all tar sands, which would be disasterous. I consider the logic to be impeccable, regardless of the merits of any of Hansen's other claims about those tar sands.
56196. Robert Marston at 07:03 AM on 26 July 2012
       Tar Sands Oil - An Environmental Disaster
       I think it's more an issue of going for the unconventional fuels. If we add tar sands, tight oil, oil shale, tight gas, methane hydrates, ultra deep water oil, and unconventional coal, we're on a road to increasing carbon emissions through at least 2030. You can't hit 2 degrees C in a scenario like that. Not by a long shot. Last year, the world emitted 31.6 billion metric tons of CO2, 3.2 percent more than the previous year. Fatih Birol: "When I look at this data, the trend is perfectly in line with a temperature increase of 6 degrees Celsius (by 2050), which would have devastating consequences for the planet." At the current growth rate, we're set to hit the trillion ton limit by around 2030 or even before. Much of the growth in fossil fuel use is coming from unconventional fuels like tar sands and since the extraction and enrichment process for tar sands is very similar to oil shale (which is a much, much larger resource), it's really critical we stuff that genie back in the bottle ASAP.
56197. vrooomie at 06:28 AM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Chris@...multiples: It *generally* does not look very good, to contantly cite Wikipedia as a *primary* source of data. Nothing wrong with using it here and there but in addition to your dodging Sphaerica's direct questions, I would think you'd use more academic sources to back up what you posit.
56198. Phil at 06:28 AM on 26 July 2012
       Climate Change Cluedo: Anthropogenic CO2
       Because the process of ozone depletion causes oxygen depletion. This statement is incorrect. Ozone depletion produces oxygen, as the wikipedia articles referenced describe.
56199. dana1981 at 04:51 AM on 26 July 2012
       Tar Sands Oil - An Environmental Disaster
       Clyde, I think we're in agreement with Hansen, who says

       "If we turn to these dirtiest of fuels, instead of finding ways to phase out our addiction to fossil fuels, there is no hope of keeping carbon concentrations below 500 p.p.m....weneed to start reducing emissions significantly, not create new ways to increase them"

       That's what we said in the above post. However, the amount of carbon which will be released by exploiting the tar sands is still not a climate catastrophe-causing quantity of carbon emissions. The problem is in the approach that we would be taking, exploiting unconventional fossil fuel sources rather than leaving as much carbon in the ground as possible. It represents taking the completely wrong approach, but just by the numbers, the tar sands emissions by themselves aren't going to mean the difference between catastrophe and non-catastrophe.
56200. vrooomie at 04:40 AM on 26 July 2012
       Earth's five mass extinction events
       Geologista@68: Chances are you are long gone, and may not respond but just in case you may actually get word of this...this "geologita" would like you to provide definitive support, in the form of peer-reviewed sources, that back up your *highly* dogmatic assertion. "7)When looking at the fragility of reef systems and the oceans biomass natural and man-made hazards have impacted their growth and health but NOT FROM CO2." I will be astonished when/if you do/can.
       Moderator Response: [DB] Geologista has indeed not commented here since.

Prev  1116  1117  1118  1119  1120  1121  1122  1123  1124  1125  1126  1127  1128  1129  1130  1131  Next