Recent Comments

Prev  2499  2500  2501  2502  2503  2504  2505  2506  2507  2508  2509  2510  2511  2512  2513  2514  Next

Comments 125301 to 125350:

125301. papabob at 13:59 PM on 15 February 2010
        The Dunning-Kruger effect and the climate debate
        Thank you for this article. I spent some years in the Air Force as a weather analyist and forecaster, way back when. I have tried to keep up in the meanwhile as the subject has been of interest since my pre teen years. It is refreshing to see some one else tell us to try to know what we don't know and remember that the more we know about this subject, the more we need to know before we can consider ourselves knowlegeable enough to argue absolutes.I don't believe that there are any absolutes. I wish we had had the technology back in the fifties and early sixties like we do now. I think that the "climate change" subject would be less contraversial.
125302. Marcus at 13:57 PM on 15 February 2010
        Is CO2 a pollutant?
        I know we're discussing the science-& not the economics, of CO2-emissions, but I think RSVP's claims need to be addressed. The idea that reducing anthropogenic CO2 emissions will come with great economic pain, for all, is often the "last line of defense" of the contrarian camp. Yet this is, in fact, far from the truth. Around 30%-50% of all electricity use, across the world, is the result of energy inefficiency in the domestic, commercial & industrial sectors of the economy. Similarly, about 20% of all fuel use is due to inefficient use of transportation. So here we have measures for reducing CO2 which-far from being painful-might actually *improve* economic well being. Aside from direct efficiency issues, there are also things like Co-generation, moving freight long distance by rail rather than road, increasing the use of car-pooling, public transport & tele-commuting to eliminate peak-hour traffic snarls & improvement in street lighting to reduce lighting scatter & thus eliminate light pollution & allow for lower wattage globes. Beyond this there are things like using methane from land fill & sewerage plants to generate electricity-thus killing 2 birds with one stone-& implementing bio-sequestration at all fossil fueled power stations. So, even without considering electric vehicles or solar/wind/tidal power, we already have a host of measures at our disposal for reducing CO2 emissions with no long-term harm (&, in fact, with long-term economic & health benefits). Of course there is also the need to consider our obsession with perpetual economic growth. Instead of focussing on ever-increasing GDP growth, our society should instead focus attention on increasing GDP/capita. Remove this "need" for perpetual growth, & many of our current economic & environmental problems might just start to solve themselves!
125303. Tom Dayton at 13:14 PM on 15 February 2010
        On the reliability of the U.S. Surface Temperature Record
        diogene, no, this line of logic does not rely on assumptions, because Menne (2010) analyzed the observations. The "poorly" sited stations (one graph line) had the same trend as the "well" sited stations (a different graph line). No, airconditioner users were not given instructions about use of the airconditioner. (The stations should not have been installed there in the first place.) But that doesn't matter, as has been shown empirically by Menne. No assumptions required. Just look at the actual trends. It turns out to be a fact that any such effects are inconsequential. That was not a foregone conclusion; as you wrote, it is easy to imagine that the effects could be profound. But facts are facts.
125304. Doug Bostrom at 13:05 PM on 15 February 2010
        On the reliability of the U.S. Surface Temperature Record
        diogene at 12:59 PM on 15 February, 2010 Probably what is most difficult about Watts' fallacy is its fundamental simplicity. The very fact it is so -wrong- makes it easy to overshoot the basic error Watts committed and get lost in a myriad of irrelevant details. Think of it as a word problem you might have encountered in middle school. Remember all the extra information that used to be thrown in, distracting you from the actual question? Don't let the extra verbiage devoted to this topic fool you. Tom Dayton explained Watts' fallacy nicely, and there are numerous other simple explanations scattered throughout the comments in this thread. I suggest you read through and find an explanation that works for you.
125305. diogene at 12:59 PM on 15 February 2010
        On the reliability of the U.S. Surface Temperature Record
        Uhh, does this line of logic rely on assumptions, that the thermometer heating is constant over short and long timeframes? I'm concerned that the counterargument will be that the onset of AGW might be said to be at a similar time as the onset of widespread airconditioner installation at USCRN networks. I imagine that some might say the A/C installation would have an anomalous effect on the "anomaly". Are the A/C users at CRN 3,4,5 stations directed to use the A/C unit in a consistent way to ensure the constant differential due to thermometer heating? I didn't see this treated in Menne2010. One other point; Did Watts analysis determine whether the A/C units were operable in winter as 'heat pumps'? Thanks for trying to help. I am up against some nontrivial resistance here... Dio
125306. Tom Dayton at 12:34 PM on 15 February 2010
        On the reliability of the U.S. Surface Temperature Record
        diogene, a major part of the answer to your question 4 is that for a "bias" to be a bias relevant to climate change, it must be a bias in the trend of the same station - the change in the same day's or month's temperature over years, of the same station. If Station A in the northern hemisphere is next to an air conditioner coil and Station B (also in the northern hemisphere) is not, on July 18 Station A probably will be warmer than Station B--but that's in the absolute temperature on that one day. On that same July day exactly one year later, A probably again will be warmer than B, but by the same amount as on that day the previous year. The year-to-year trend in the temperature of Station A compared to itself is the measure that is relevant to climate change. Ditto for Station B. The difference in temperature between A and B easily can be imagined to be constant from year to year, and the actual observations support that imagination. Temperature "anomaly" is what you see graphed in nearly all climate change graphs. That "anomaly" contains the information about that year-to-year difference for the same station on the same day or month, but filters out the absolute temperature that is the difference between Station A and Station B.
125307. diogene at 11:11 AM on 15 February 2010
        On the reliability of the U.S. Surface Temperature Record
        Hello; I was trying to explain the implication of Menne2010 regarding Watts' work, and I was unable to make my point. There seemed to be ~4 issues for which I had no answer. Hopefully the experts here can help me clarify my thinking and the people around me. 1. Did Watts incorrectly apply the purported URCRN Siting Handbook criteria http://www1.ncdc.noaa.gov/pub/data/uscrn/documentation/program/X030FullDocumentD0.pdf section 2.2.1? 2. Assuming that the criteria were correctly applied by Watts, why does the handbook list estimated errors of 1C, >=2C, and >=5C for CRN classes 3,4,5? 3. How does Menne2010 address questions 1 and/or 2? 4. I'm having trouble conveying a simple explanation of how Menne2010 or anyone could prove that nearby heatsources would not create a heat bias in measuring air temperatures. I see the analysis. But I can't explain it to anyone. What is the mechanisms that apparently immunizes the CRN 3,4,5 thermometers (MMTS or LIG) from nearby heaters? Thanks, I wish I could handle this myself, but I need help. Dio
125308. Marcus at 09:46 AM on 15 February 2010
        Is CO2 a pollutant?
        From Peru, I think that is almost a certainty. It's easy to accept that nearly 8,000 years of agriculture would have some impact on CO2 concentrations in the atmosphere. Yet compare 20ppm over 8,000 years to around 100ppm in the last 250 years (with the bulk being in just the last 60 years). It really suggests that the Industrial Revolution is a much bigger threat to our atmosphere than the previous Agricultural Revolution.
125309. Philippe Chantreau at 08:02 AM on 15 February 2010
        Jupiter is warming
        One thing I would not want to distract from is consistency of argument, as in papertiger saying in post 16: "In fact the poles are already ten or twenty degrees colder then the equator. Hot equator, cold poles. Exactly what you would expect from a solar dominated weather system." http://www.skepticalscience.com/global-warming-on-jupiter.htm#66 Then, papertiger goes on putting words in Phil Marcus' mouth that none of the quotes justifies, but that are nevertheless the exact opposite of his previous prediction on the planet's heat distribution: "He seems to be saying that deep convection ie heat radiating from the planet would result in the pole being 30 K colder then the equator." That's the very opposite of your previously quoted theory but that's not what Phil Marcus is saying at all. If papertiger truly understood what Marcus is saying why would he use the tentative "seem to be saying"? Marcus is saying that, in theory, considering the balance of blackbody radiation from internal heat and solar radiation, one would expect to have a certain latidudinal heat distribution. The observations show something different, i.e. "Currently the weather layer (containing the clouds and vortices) is nearly isothermal in latitude." He then emphasizes that convection can not be responsible for mixing that solar heat to produce the observed uniformity. That would suggest that the amount of solar heat has in fact a modest contribution, although this is not addressed in the letter. Marcus' letter to Nature can be found here http://www.me.berkeley.edu/cfd/people/marcus/nature02470.pdf It makes no mention whatsoever of a solar influence on Jupiter's 70 year cycle as postulated by the author. Instead, Marcus' hypothesis relies exclusively on fluid dynamics and it is clear from the letter that the 70 years cycle is generated by Jupiter itself. Nowhere in the letter does Marcus suggest that variations in solar irradiance are responsible for the cycle. The climate change consists of a change in the latidudinal heat distribution. Based on this, one could say that, from Marcus' point of view, the single largest influence on Jupiter's climate is the planet's rotational velocity. His Berkeley page also links to this paper http://www.me.berkeley.edu/cfd/people/marcus/icarus162.pdf It references this Flasar et al (that includes Gierasch) paper, in which convection and lightning storms are examined in light of the Galileo data: http://www.lpl.arizona.edu/~showman/publications/ingersolletal-2004.pdf
125310. Riccardo at 04:03 AM on 15 February 2010
        It hasn't warmed since 1998
        Update. As I suspected but could not prove (yet), it was not what Jones said. Here's is the full quote from the original BBC interview: "Question - Do you agree that from 1995 to the present there has been no statistically-significant global warming Answer - Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods. " So, once again, at the Daily Mail they showed that they do not understand science but unrelentlessly continue to misguide they readers.
125311. carrot eater at 03:21 AM on 15 February 2010
        Is CO2 a pollutant?
        suibhne: "An atmosphere radiating back to the Earths surface explained by using the Stephan Boltzman equation, but then saying that this was not meant to be taken seriously." It's to be taken seriously, inasmuch as it shows the basic concept of how back-radiation from the atmosphere can cause the surface to be warmer than it otherwise would be. In order to show that basic concept, you don't need spectral detail. Any source that uses this cartoon model should make clear that it is making a lot of simplifications: using a single-slab atmosphere, and ignoring temperature variations within the atmosphere (the lapse rate), ignoring convection, ignoring wavelength-dependent detail. Once you add all this in, you end up with a fully fledged climate model, with thousands of lines of code. But that doesn't mean simple models aren't of any value. So, you seem to say you found a website where a very simple model is presented, without those caveats telling the reader there is much being left out. If you tell us what website this is, perhaps we could have a look, and suggest to the author that a couple sentences be put it, to that effect.
125312. From Peru at 02:03 AM on 15 February 2010
        Is CO2 a pollutant?
        One thing: CO2 rose 100 ppm since Industrial Revolution 200 years ago. BUT: CO2 ALSO rose 20-30 ppm since 6000 years ago until 1700 AD. Could this be a result of the AGRICULTURAL Revolution(i.e from land use change)?
125313. Riccardo at 20:59 PM on 14 February 2010
        It hasn't warmed since 1998
        hint: don't take Mail Online words for it. Further down you'll read "The trend is a warming trend". There's clearly something wrong in what they report.
125314. Timothy Chase at 20:33 PM on 14 February 2010
        Is CO2 a pollutant?
        Which is the More Powerful Greenhouse Gas?, part II of II Water vapor that is in the atmosphere tends to be rained out very quickly having a half-life of about 10 days -- and the same is true of tropospheric aerosols as they tend to fall out with the rain. If it weren't for the corresponding process of evaporation the atmosphere would rapidly dry out. Moreover the amount of water vapor in the atmosphere is very sensative to temperature. If you raise the temperature by 1°C the absolute humidity will quickly rise by 8% due to the higher rate of evaporation, and if you raise the temperature by 10°C the absolute humidity will double. But if you raise the amount of water vapor in the atmosphere without raising the temperature right away then you will increase the rate of precipitation without a corresponding increase in the rate of evaporation. And it takes a while for the climate system to warm given the large thermal inertia of the earth's oceans and consequent characteristic time scale that is about thirty years. Please see: Spencer’s Folly July 28, 2008 http://tamino.wordpress.com/2008/07/28/spencers-folly/ But a large part of a "slug" of carbon dioxide injected into the atmosphere will remain in the atmosphere for years, decades, centuries and even millenia. As such it remains in the atmosphere long enough to maintain an imbalance between the rate at which solar radiation is being absorbed and the rate at which thermal radiation escapes the atmosphere, reducing the later. With the reduced rate at which thermal radiation escapes the temperature will rise, increasing the rate of evaporation which acts as a positive feedback, increasing the temperature still further, and once the new short-term feedback Charney equilibrium is achieved, while a doubling of carbon dioxide would raise the temperature by a little more than 1°C by itself, all the feedback will likely add about 2°C to this, bringing the total warming to 3°C. Please see for example: Skeptical Science: "Water vapor is the most powerful greenhouse gas" http://www.skepticalscience.com/water-vapor-greenhouse-gas.htm David Archer & Victor Brovkin (2008) The millennial atmospheric lifetime of anthropogenic CO₂, Climatic Change 90:283–297 http://geosci.uchicago.edu/~archer/reprints/archer.2008.tail_implications.pdf So which is more powerful? Carbon dioxide or water vapor. The first because it leads the latter. Please see: Richard Alley – The Biggest Control Knob: Carbon Dioxide in Earth’s Climate History December 19, 2009 http://thingsbreak.wordpress.com/2009/12/19/richard-alley-the-biggest-control-knob-carbon-dioxide-in-earths-climate-history/
125315. Timothy Chase at 20:32 PM on 14 February 2010
        Is CO2 a pollutant?
        Which is the More Powerful Greenhouse Gas?, part I of II RSVP wrote in 95:

        This is what I understood. On Mars, the greenhouse effect due to CO2 contributes to a 10C increase in temperature. On Earth a 3C increase. If I didnt get that right, please correct me.

        Consider yourself corrected... The greenhouse effect results in the earth being 32°C warmer than it would otherwise be. See: What is the Effective Temperature of Venus Atmoz 18 Jul 2007 http://atmoz.org/blog/2007/07/18/what-is-the-effective-temperature-of-venus/ Now there are two ways of calculating how much a given greenhouse gas is responsible for of this warming. First, remove the gas in question while holding the other greenhouse gases constant -- and see how much the greenhouse effect would be reduced -- and attribute that amount to the greenhouse gas that was removed. For carbon dioxide one gets 9%, or 2.9°C. Methane 4% or 1.3°C. Water vapor 36% or 11.5°C and Ozone 3% 1°C. Grand total? 52% or 16.6°C. Second, remove all the other greenhouse gases while holding the greenhouse gas in question constant -- and see how much of the greenhouse effect remains. For carbon dioxide one gets 26% or 8.3°C, methane 9% or 2.9°C, water vapor 70% or 22.4°C, ozone 7% or 2.2°C. Grand total? 112% or 35.8°C. See: Gases released by human activity that contribute to climate change and global warming. http://www.opencarbonworld.com/wiki/greenhouse-gas.html ... for the figures. Why the difference? Because the absorption bands overlap. Remove one gas and at least some of the absorption and consequent greenhouse effect that the gas was responsible for will be taken up by the others. Remove the others and at least some of the absorption and consequent greenhouse effect that gas was responsible for will be taken up by the gas that is left. (Gavin Schmidt explained this at one point but I will have to look up the exact reference.) However, water vapor is a fast feedback. When we say "hold it constant" while changing the amount of carbon dioxide in the atmosphere this really is nothing more than a thought experiment and corresponding calculation.
125316. CBDunkerson at 20:06 PM on 14 February 2010
        Is CO2 a pollutant?
        RSVP, the '3 C increase from CO2 on Earth' is only partially correct. It is impossible to give an exact figure because many of the bands of radiation retained by different greenhouse gases overlap... so did a particular photon get retained by CO2... or water vapor... or ozone? The 9% estimate is computed by looking at average concentrations, location (e.g. CO2 can be found higher in the atmosphere than water vapor and thus accounts for more IR absorption there), circulation, and so forth. However, if we could somehow magically remove the overlapping IR bands from other greenhouse gases (while retaining all other bands they absorb) then CO2 would account for 26% of the 32C greenhouse warming... 8.32 C. That is a better comparison for Mars in terms of greenhouse potential since there are few other greenhouse gases there. Of course, Mars also has more CO2... but less atmospheric pressure. So you've got alot of conflicting variables in play here. Also, it was the greenhouse effect itself which disguised Venus for so long. All that CO2 in the atmosphere preventing heat from escaping means that the surface of Venus is very hot... but that heat doesn't escape out to space where we could observe it. The greenhouse effect keeps the heat contained and the upper layers of Venus's atmosphere actually seem quite hospitable and Earthlike. It was the probes which showed otherwise.
125317. Doug Bostrom at 18:50 PM on 14 February 2010
        Is CO2 a pollutant?
        RSVP at 18:39 PM on 14 February, 2010 "What fundamental science was missing at that time to have required the loss of so many space probes? " Not science, data, such as what was the atmospheric pressure at the surface, the temperature, things like that.
125318. Doug Bostrom at 18:40 PM on 14 February 2010
        It hasn't warmed since 1998
        VinceOZ at 17:17 PM on 14 February, 2010 Try as the Mail did to spin the interview, there's really not much there. Here's the part I found most shocking: "Discussing the interview, the BBC’s environmental analyst Roger Harrabin said he had spoken to colleagues of Professor Jones who had told him that his strengths included integrity and doggedness but not record-keeping and office tidying." Tut-tut. Lots of integrity but he can't keep his office tidy. Surely he must go. Vince, what say you to the graph in #40, here?
125319. RSVP at 18:39 PM on 14 February 2010
        Is CO2 a pollutant?
        CBDunkerson So where is the problem? Riccardo prompted me to "go back reading". I did. This is what I understood. On Mars, the greenhouse effect due to CO2 contributes to a 10C increase in temperature. On Earth a 3C increase. If I didnt get that right, please correct me. Now, my turn. I was saying earlier that Mars and Earth actually have "equivalence" of CO2 in their atmospheres in the sense that if you remove all other gases from that of the Earth, you would have about the same coverage of CO2 on the Earth as on Mars. In fact, as Earth is a larger planet (perhaps, and in this I am not hold my hand to any flames), there is even more CO2 volumetrically. But at any rate, these planets are at least par in some sense. Furthermore, both planets have the same rotation of around 24 hrs. Even though Mars is further from the Sun, according to you, the greenhouse effect is 3 times as high. Other posters have actually alluded to there not being enough pressure to activate the CO2 for spectral broadening etc. Perhaps the albedo is lower on Mars than the Earth, which I assume would favor more surface IR and more greenhouse heating. So, I dont think there is any problem, however, I do think it rather unfair to dismiss these questions as irrelevant, especially when a lot of the marketing behind the deleterious effects of CO2 has been based on image of the greenhouse effect on Venus. By the way, one last comment. With all that rocket science, astronomy, physics, chemistry, etc., apparently the situation on Venus came as a surprise when they actually sent probes over there. It should have been predictable. What fundamental science was missing at that time to have required the loss of so many space probes?
125320. RSVP at 17:21 PM on 14 February 2010
        Is CO2 a pollutant?
        Mike Air is what we breath here on Earth. "Air" by definition is a specific a mixture of gases, which by the way is changing over time as we can see from the graph.
125321. VinceOZ at 17:17 PM on 14 February 2010
        It hasn't warmed since 1998
        How does this jive with what Phil Jones is saying now that there has been no warming since 1995. Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995 http://tr.im/O7vd How can it be both?
125322. Timothy Chase at 16:04 PM on 14 February 2010
        Is CO2 a pollutant?
        CORRECTION: I meant "Thank you CBDunkerson. You've got the right figures -- and my attempt was seriously out of wack...." Jesh!
125323. Timothy Chase at 16:02 PM on 14 February 2010
        Is CO2 a pollutant?
        CBDunkerson wrote in 81:

        Look at effective temperatures, that is the temperature the planet would have based solely on the amount of radiation hitting it and its albedo, vs mean surface temperatures; Eff Mean Venus: 227 K 735 K Earth: 255 K 287 K Mars: 217 K 227 K

        Thank you CBDunkerson. You've got the wrong figures -- and my attempt was seriously out of wack. 1 minus the albedo for the absorbed, fourth power of the temperature for the watts implying fourth root of watts to get the temp... I found the following that shows the right approach to calculating what the temperature of a planet minus the greenhouse effect = the effective temperature. What is the Effective Temperature of Venus Atmoz 18 Jul 2007 http://atmoz.org/blog/2007/07/18/what-is-the-effective-temperature-of-venus/ I shoulda known better. Would have if I hadn't been in such a hurry.
125324. Doug Bostrom at 15:48 PM on 14 February 2010
        It's the sun
        Dan, I've seen that writeup elsewhere. Could you go through it step-by-step, being especially careful to help us understand the following things written by the author: --"The proportionality constant, 6.36E-9, was adjusted to get a fairly constant net energy from 1700 to about 1940"; Why? --"The up trend or down trend periods ascribed to the Pacific Decadal Oscillation (PDO) are taken as 32 years long for all periods." Why 32 years for all periods? --"The temperature range for the PDOs alone was taken to be 0.45 K for all of the PDOs." Why? For a PDO downtrend, the value added to the above sunspot calculation is 0.45 minus 0.45 multiplied by the fraction of the PDO time period that has taken place." Why?
125325. Doug Bostrom at 14:15 PM on 14 February 2010
        What the IPCC and peer-reviewed science say about Amazonian forests
        Charlie A at 13:41 PM on 14 February, 2010 Telegraph: "Yet it has now come to light that the IPCC, ignoring the evidence of its own experts, deliberately published the claim for propaganda purposes." An opinion piece, apparently, and odd that the Telegraph should consider unsubstantiated claims by the IPCC worse than what they themselves publish.
125326. Charlie A at 13:41 PM on 14 February 2010
        What the IPCC and peer-reviewed science say about Amazonian forests
        http://www.telegraph.co.uk/comment/columnists/christopherbooker/7231386/African-crops-yield-another-catastrophe-for-the-IPCC.html is an article with lots of details on the IPCC claim of 50% reduction in rain-fed agriculture in Africa by 2020. It includes info on how the lead author had a company that accepted government money to study potential problems and came up with conclusion that there were no significant potential problems. Then that same lead author wrote the alarmist claims that don't jibe with his own company's studies.
125327. Dan Pangburn at 13:03 PM on 14 February 2010
        It's the sun
        A graph of sunspot count vs. time shows that some cycles are high for short periods and some are not as high but for longer periods. The relevant measure is energy which is the combination of both magnitude and time as in the time-integral of sunspot count. Subtracting the energy radiated from the planet results in the net energy retained by the planet. An appropriate scale factor relates net energy to average global temperature anomaly. Combine this with the Effective Sea Surface Temperature and the result is a model that accurately predicts average global temperature anomalies since 1895. That is 114 years…and counting. It is not necessary to include changes to the level of CO2 or any other ghg. Anyone that can use EXCEL can do this. Or, see it done already at http://climaterealists.com/attachments/database/TwentiethCenturyTemperatureCorrelationupdate.pdf which has links to the source data. (Replace all references to PDO with ESST which is short for Effective Sea Surface Temperature).
125328. Philippe Chantreau at 12:56 PM on 14 February 2010
        Is CO2 a pollutant?
        RSVP, Mercury is closer to the Sun than Venus, yet it's not as hot. Also, if I recall right, although Venus always presents the same side to the Sun, there is not that much difference between the sunny and shady side temperatures.
125329. Mike1637 at 10:53 AM on 14 February 2010
        Is CO2 a pollutant?
        RSVP: "Air on Mars?" That's interesting. I guess I know what you meant. Why should you find that "interesting" unless you knew nothing about Mars in the first place? Is there no "air" on Mars? If so, photographs from the Mars rovers showing dust storms and dust-devils on the surface are indeed mysterious. There is already plenty of information in the responses here and elsewhere on this website to show that the Mars/CO2 sceptical argument is wrong, or misleading, or irrelevant (actually a bit of each). What is interesting, is that you still want to use it.
125330. Riccardo at 10:49 AM on 14 February 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        Steve, the authors refer explicitly to the negative mass balance component averaged over one year. This surely means that on an annual basis the contribution is small and the eventual water scarcity we see now is not due to glaciers retreat. But, given that they are indeed retreating (they say 20% in 40 years), in the long run you will miss the whole seasonal melting during the arid season. And that will be a problem.
125331. Timothy Chase at 10:22 AM on 14 February 2010
        Is CO2 a pollutant?
        PS That's right: just going off of the albedos and distances from the sun, Venus should be just one degree warmer than the earth -- where we omit the greenhouse effect of both planets due to their greenhouse gases.
125332. Steve1644 at 10:21 AM on 14 February 2010
        The IPCC's 2035 prediction about Himalayan glaciers
        Maybe we need more hydrologists and fewer glaciologists on the case. At the December 2009 AWG Conference in San Francisco - Jeff Kargel from the University of Arizona presented on behalf of a number of experts on the Himalayan Glacier controversy. I was struck by their conclusion that the glaciers only contribute 1.2% of the water flow in the three principal river systems. If that is accurate or close to being accurate, would it not call into question whether the complete disappearance of the glaciers would have any significant effect on the river flows? Following is the quote, and following that the link to the full presentation. Page 41 “9. As we have calculated, melting glaciers (specifically, negative mass balance components of the melt) contribute an estimated 1.2% (perhaps factor of 2 uncertain) of total runoff of three of the most important drainages, the Indus, Ganges, and Brahmaputra combined. The seasonal flow regulation influences and the negative mass balance is more important in local drainages close to the glacier sources, w[h]ere glaciers can dominate the hydrology in arid regions, but on the scale of the subcontinent, glaciers are secondary players in looming hydrologic problems, which stem more from population growth and inefficiency of water resource distribution and application.” The full presentation may be found at http://web.hwr.arizona.edu/~gleonard/2009Dec-FallAGU-Soot-PressConference-Backgrounder-Kargel.pdf
125333. Timothy Chase at 10:14 AM on 14 February 2010
        Is CO2 a pollutant?
        RSVP wrote in 84:

        CBDunkerson "The vast difference in mean temperature is because Venus has a very thick dense atmosphere and Mars a very thin diffuse atmosphere." What about the distance from the Sun? Should I continue reading?

        Here is the distance of Venus from the Sun:

        Orbital Semimajor Axis: 0.72 AU (Earth=1 AU) Venus Statistics http://www.windows.ucar.edu/tour/link=/venus/statistics.html

        The albedo of the earth:

        For example, the albedo of the Earth is 0.39 (Kaufmann) and this affects the equilibrium temperature of the Earth. Albedo of the Earth http://hyperphysics.phy-astr.gsu.edu/HBASE/phyopt/albedo.html

        The albedo of Venus due to the highly reflective sulfuric acid in its upper atmosphere:

        The bond albedo of Venus is 0.75. Albedo is a measurement of the reflectivity of an object. Albedo of Venus http://www.universetoday.com/guide-to-space/venus/albedo-of-venus/

        Put those numbers together and the temperature of Venus without a greenhouse effect would be roughly the same as earth's without a greenhouse effect: -16°C as opposed to -17°C. The actual temperature of Venus is 457°C and the actual average temperature of the earth is 14°C.
125334. Dan at 09:39 AM on 14 February 2010
        Is CO2 a pollutant?
        One commenter said: //If CO2 is "pollutant" what term would you reserve for e.g. dioxin, the stuff involved in the Union Carbide disaster, Bhopal, India, 1984? Thousands perished.// It seems that you are confusing "pollutant" with "toxin". They are not the same thing, and "toxic" may or may not both apply to a pollutant.
125335. Riccardo at 09:23 AM on 14 February 2010
        Is CO2 a pollutant?
        RSVP, distance from the sun is included in the calculation of the mean effective temperature CBDunkerson showed; just for info, planetary albedo is also included. Go on reading then, or should i say go back reading?
125336. RSVP at 09:21 AM on 14 February 2010
        Is CO2 a pollutant?
        dhogaza "Earlier you've been told: Due to the very low air pressure" "Air on Mars?". That's interesting. I guess I know what you meant. Why not just quantify the difference pressure makes and we can get on with it. However a poster name Gord was saying, that only CO2 at a lower temperature would absorb IR. This would be CO2 at higher altitudes which I assume would also be at a lower pressure. And, by the way, I never said CO2 isnt a greenhouse gas. All I have ever challenged is the idea that such a rarified gas in our atmosphere is modulating ice age cycles, and or acting as the main cause of a current global warming trend.
125337. RSVP at 09:08 AM on 14 February 2010
        Is CO2 a pollutant?
        CBDunkerson "The vast difference in mean temperature is because Venus has a very thick dense atmosphere and Mars a very thin diffuse atmosphere." What about the distance from the Sun? Should I continue reading?
125338. Timothy Chase at 08:44 AM on 14 February 2010
        Is CO2 a pollutant?
        Science and Skepticism, Part II of II But there are rather severe limits to what someone can be taught if they have no desire to learn, and beyond a certain point flood of requests for details and data that no one is likely to use simply becomes an instrument by which to waste people's time. As Gavin Schmidt wrote in a private letter to Ben Santer:

        The contrarians have found that there is actually no limit to what you can ask people for (raw data, intermediate steps, additional calculations, sensitivity calculations, all the code, a workable version of the code on any platform, etc) and like Som-ali pirates they have found that once someone has paid up, they can always shake them down again. Elizabeth May: An Informed Look at the East Anglia Emails 3 December 09 http://www.desmogblog.com/elizabeth-may-informed-look-east-anglia-emails

        ... and this seems very much to be the case given certain orchestrated campaigns. And it has recently been taken to any entirely new level by the Competitive Enterprise Institute:

        Here's just one part of the request: 1. of all records, documents, internal communications, and other relevant covered material created by, provided to, received, and or sent by an official or employee of NASA including but not limited to NASSA GISS, that in any way relate to the, receipt, handling, processing, or disposition of "Freedom of Information Act," or "FOIA" requests;... CEI requests a significant percent of all records produced by NASA Thursday, February 04, 2010 http://backseatdriving.blogspot.com/2010/02/cei-requests-significant-percent-of-all.html

        It is helpful to keep in mind the fact that many of the same organizations which are "encouraging" skepticism with regard to global warming are the same organizations that were encouraging skepticism with respect to the link between tobacco and health problems. I put together a list here:

        For those who are interested, here is a list in alphabetical order of 32 organizations involved in both the denial campaign surrounding tobacco and that surrounding Anthropogenic Global Warming: 1. Acton Institute http://www.sourcewatch.org/index.php?title=Acton_Institute http://www.exxonsecrets.org/html/orgfactsheet.php?id=5 2. American Legislative Exchange Council (ALEC) http://www.sourcewatch.org/index.php/American_Legislative_Exchange_Council http://www.exxonsecrets.org/html/orgfactsheet.php?id=10 ... Comment 855 of Real Climate's "Unforced Variations" http://www.realclimate.org/index.php/archives/2009/12/unforced-variations/comment-page-18/#comment-151461

        Guess what? The Competitive Enterprise Institute is on there as number 10. With respect to skepticism regarding the conclusions of established science, it is helpful to keep the following quote from an internal Brown and Williams document in mind:

        Doubt is our product, since it is the best means of competing with the “body of fact” that exists in the mind of the general public. It is also the means of establishing a controversy. Smoking and Health Proposal (1969) http://tobaccodocuments.org/landman/332506.html

125339. Timothy Chase at 08:43 AM on 14 February 2010
        Is CO2 a pollutant?
        suibhne wrote in 45:

        I still cannot get my head around the idea that co2 gas with two significant quantised IR bands can radiate in a way explained by Stephen Boltzman equation!

        carrot eater wrote in 46

        It doesn't, really. That's why detailed radiation transfer calculations are necessary, explicitly considering the full spectrum of wavelengths, and therefore those spectral lines. Planck's Law gives the maximum possible radiation at any given wavelength; S-B integrates that over all wavelengths. To deal with something with quantised bands in the context of Planck's Law, you'd have to introduce a wavelength-dependent emissivity.

        suibhne wrote in 78:

        Thanks for your explanation carrot eater. I will try to examine the more sophisticated model. You must admit though that people are entitled to be sceptical when they are told of; A greenhouse effect which we are then told is nothing like a greenhouse at all. An atmosphere radiating back to the Earths surface explained by using the Stephan Boltzman equation, but then saying that this was not meant to be taken seriously.

        suibhne, when you write, "You must admit though that people are entitled to be sceptical when they are told of; A greenhouse effect which we are then told is nothing like a greenhouse at all," it helps to realize that the greenhouse effect is actually a lot like the way that a greenhouse works -- in that while it permits energy to enter the system due to transparency to visible light (in the case of the greenhouse by means of transparent glass but in the case of the greenhouse effect due to the transparency of the atmosphere itself), it reduces the rate at which thermal energy is able to leave. Yes, of course there is the difference between the greenhouse that reduces moist air convection and the greenhouse effect which reduces the loss of heat due to "gasp!" invisible light. No, the earth's atmosphere doesn't have a glass roof -- but using such images (or the image of a blanket -- whether it is made of wool or one of the reflective space blankets that works primarily by reducing the loss of heat by thermal radiation) but people typically find such images and metaphors more helpful than an explanation that typically presumes a bachelor's degree or higher in physics. When you write, "You must admit though that people are entitled to be sceptical when they are told of; ... An atmosphere radiating back to the Earths surface explained by using the Stephan Boltzman equation, but then saying that this was not meant to be taken seriously," judging from carrot eater's explanation it is meant to be taken seriously -- but it is the Stephan Boltzmann law of blackbody radiation -- and this presupposes an absorptivity/emissivity of 1 (meaning that the object is completely black at all wavelengths). If you want to apply it to objects that are grey then you need to take into account how the absorptivity will be less than 1. If you want to apply it to realistic bodies that have an absorptivity that varies with wavelength then you need to take into account the fact that the absorptivity isn't a constant with respect to wavelength. The absorption and emission of radiation by a true black body as a continuem of constant absorptivity and emissivity lies at one end of "the spectra," the absorption and emission lines of certain alloys, crystals, dusts and greenhouse gases at the other end. But from one end to the other it is all thermal radiation. You want to really understand the reasons for the differences? Be prepared to take courses in thermodynamics, quantum mechanics, statistical mechanics and radiation transfer theory. You aren't really interested in going that far? Then you really don't have much reason for complaining that the science is opaque. Nevertheless...

        I think that we can all agree on open science with open data and traditional honesty where criticism is welcomed and not seen as a threat. As Mao once said "let a hundred flowers bloom, and a thousand thoughts contend"

        ... there is a great deal of science that is online. For example, the infrared imaging of the AIRS (Atmospheric InfraRed Sounder) instrument has an entire website devoted to it here: AIRS http://airs.jpl.nasa.gov ... and extensive catalogue of online images here: AIRS: Multimedia http://airs.jpl.nasa.gov/multimedia/multimedia_toc/ ... documentation, specifications, an online database of all the peer reviewed articles that have made use of its data, a selection of available articles -- all of which I have linked to here. All documentation and data is open access and free to the public -- or at least those members of the public that are willing to take the time and look for it. You have climatologists making available detailed explanations for the laymen, a number of which I linked to here specifically regarding how thermal radiation laws apply to greenhouse gases. You can even download entire climate models -- one version after another as they are developed by NASA GISS. Heck, one recent go at explaining the radiation transfer theory that underlies our understanding of the greenhouse effect by a climatologist was made less than a week ago and can be found here: Another Try MONDAY, FEBRUARY 08, 2010 http://rabett.blogspot.com/2010/02/another-try.html
125340. CBDunkerson at 08:20 AM on 14 February 2010
        Is CO2 a pollutant?
        RSVP, I don't understand why you're still on this 'Mars has carbon dioxide so it should not be cold' bit. Look at effective temperatures, that is the temperature the planet would have based solely on the amount of radiation hitting it and its albedo, vs mean surface temperatures; Eff Mean Venus: 227 K 735 K Earth: 255 K 287 K Mars: 217 K 227 K So, all three planets have some amount of additional heat which has to come either from internal thermal activity (which is VERY low on Mars) or a 'greenhouse effect' in the atmosphere, which is in fact responsible for nearly all the 'extra' heat in all three of these cases. Like Mars, the atmosphere of Venus is over 95% carbon dioxide. The two planets also have very similar effective temperatures. The vast difference in mean temperature is because Venus has a very thick dense atmosphere and Mars a very thin diffuse atmosphere. Earth's atmosphere bears virtually no resemblance to that of either of these two other planets... either in density or composition. The 32 C of greenhouse warming observed here is primarily due to water vapor. If all greenhouse gases with overlapping spectra were removed than CO2 would contribute about 26% of the Earth's greenhouse effect. The usual estimate of how much it actually contributes currently is about 9%... or a little under 3 C. On Mars CO2 is responsible for virtually all of the 10 C greenhouse warming. So where is the problem? Mars is warmer than it would be without the CO2 greenhouse effect. If the atmosphere were not so thin it would have a stronger greenhouse effect (cf. Venus), but even as it is Mars experiences much more warming from CO2 than Earth does.
125341. dhogaza at 07:30 AM on 14 February 2010
        Is CO2 a pollutant?
        RSVP:

        Mars and Earth have "equivalent" amounts of CO2

        Earlier you've been told:

        Due to the very low air pressure, so that spectral lines remain very narrow, lacking the so-called pressure (or collisional) broadening.

        Either you don't understand what is meant by collisional broadening, in which case you should go read one of the links provided above ... Or you're intentionally throwing out well-known, 60 year old, physics, pretending it doesn't exist. Which is it? The first possibility is curable.
125342. Wilson_Energy at 07:11 AM on 14 February 2010
        Skeptical Science now an iPhone app
        Windows Phone app too please! Would be very handy!
125343. Doug Bostrom at 06:43 AM on 14 February 2010
        Is CO2 a pollutant?
        RSVP at 02:08 AM on 14 February, 2010 Even letting aside Phillipe's good point regarding the whole issue of net albedo effects of solar capture systems, we don't really need to worry about the little ways we can redirect or reject energy arriving from the sun at various solar capture systems. Any changes we can make in that department are a microscopic iota compared to others we're already accidentally promoting. Here's an illustration. Considering the loss of Arctic sea ice since circa 1980, on a typical summer day in the present the Arctic ocean is absorbing more additional energy than the entire world electrical generating capacity, by a large amount. Total global electrical demand is about 16TW. Back of the envelope calculation by a favorite skeptic of mine shows -at least- 40TW of additional energy being sucked up by the Arctic ocean on a summer day as a result of ice loss. What that tells us is that the amount of energy sloshing around here is so gigantic that any effects we may cause by tweaking a few km2 of albedo with capture systems are vanishingly small. This confusion probably has a little to do with the white roof/pavement schemes being promoted for reducing energy demand. Those are aimed at cutting air conditioning costs so as to reduce fossil fuel consumption thus reducing C02 pollution. They're not about increasing the total albedo of the planet.
125344. suibhne at 05:49 AM on 14 February 2010
        Is CO2 a pollutant?
        Thanks for your explanation carrot eater. I will try to examine the more sophisticated model. You must admit though that people are entitled to be sceptical when they are told of; A greenhouse effect which we are then told is nothing like a greenhouse at all. An atmosphere radiating back to the Earths surface explained by using the Stephan Boltzman equation, but then saying that this was not meant to be taken seriously. I think that we can all agree on open science with open data and traditional honesty where criticism is welcomed and not seen as a threat. As Mao once said "let a hundred flowers bloom, and a thousand thoughts contend"
125345. Timothy Chase at 05:37 AM on 14 February 2010
        Is CO2 a pollutant?
        PS to 74 If anyone is wondering, yes, the address on the Plass paper... Strong, J. & Plass, G. N. (November 1950) The Effect of Pressure Broadening of Spectral Lines on Atmospheric Temperature. Astrophysical Journal, vol. 112, No. 3, p.365-79 http://articles.adsabs.harvard.edu//full/1950ApJ...112..365S/0000365.000.html ... actually has those dots in it. There is a pdf available as well. Incidentally, one of the points that I find interesting is that while they understood that quantized states of molecular excitation are responsible for the absorption bands and lines -- they mention a pure rotational bands (as opposed to rovibrational) of water vapor in "the region beyond 17μ on page 368 -- they were relying upon a fair amount of in the field observations as well as laboratory studies which were being carried out at the same time. For example, they state:

        Data on Absorption in the Infrared in the Stratosphere We are fortunate in having certain high-altitude measurements of the transmission characteristics of the upper atmosphere in the infrared which shows the bands that are important for our considerations. Figure 2 gives a curve representing the transmission of the atmosphere from 8 to 26 μ above 33,000 feet altitude... ibid., pg 368

        ... and:

        50 μ H₂O Band Experimental studies of the absorption of this band in the region of 10-30 μ, which will be adepquate for the purposes of this calculation, are just now being carried out. It is uncertain whether the main absorption in this region is from lines or from the wings of very strong lines at 50 μ... ibid. pg375.

        The lack of convection in the stratosphere is explained as a consequence of pressure broadening (or lack thereof) and high rate thermal emission, mention of how absorption takes place according to the square root rather than the logarithm at lower pressures. I would assume that the high altitude measurements were being performed by the military at the time for the development of fighter infrared vision or something along those lines. If anyone knows... * One other point that may be of interest. In: Pressure broadening Thursday, July 05, 2007 http://rabett.blogspot.com/2007/07/pressure-broadening-eli-has-been-happy.html ... Eli gives a link to the Spectral Calc. It is no longer there at that address. The new address is: Spectral Calc http://www.spectralcalc.com/calc/spectralcalc.php There if you are so inclined you can calculate their own absorption spectra if they are so inclined. The graphs that get produced are below the fold. Anyway, hard to imagine people arguing with physics and data which is more than half a century old. Then again, some of the science behind the greenhouse effect is more than a century old, and they will argue with that as well, and I was on the evolution/creationism front for several years... I guess I really shouldn't find it that hard to believe.
125346. RSVP at 05:35 AM on 14 February 2010
        Is CO2 a pollutant?
        Philippe Chantreau What is my point? Mars and Earth have "equivalent" amounts of CO2, (plus Mars also an almost 24 hr rotation), the difference being that on Mars the CO2 is not diluted as on Earth. These conditions appear to lend themselves to a useful comparison. Aside from this potential, given that at average temperature of the planet is around -43C, (and gets to around -120C) on the outset, it doesnt appear that the CO2 is doing a whole lot of warming on its own other than buffering temperatures any gas would.
125347. Riccardo at 05:13 AM on 14 February 2010
        Is CO2 a pollutant?
        Timothy Chase, great! I really love this good old papers. Thanks a lot.
125348. Timothy Chase at 04:01 AM on 14 February 2010
        Is CO2 a pollutant?
        jenikhollan wrote in 56:

        On Mars: there is some greenhouse, but just a faint one, several kelvins only. This is due to CO2 being the only gas there, even if a bit more abundant (I mean mass per column) than on the Earth. And, due to the very low air pressure, so that spectral lines remain very narrow, lacking the so-called pressure (or collisional) broadening.

        I just bumped into a classic from 1950, almost 60 years ago: Strong, J. & Plass, G. N. (November 1950) The Effect of Pressure Broadening of Spectral Lines on Atmospheric Temperature. Astrophysical Journal, vol. 112, No. 3, p.365-79 http://articles.adsabs.harvard.edu//full/1950ApJ...112..365S/0000365.000.html Of course if others are interested in something more recent: Pressure broadening Thursday, July 05, 2007 http://rabett.blogspot.com/2007/07/pressure-broadening-eli-has-been-happy.html High Pressure Limit. . . . Sunday, July 08, 2007 http://rabett.blogspot.com/2007/07/high-pressure-limit.html Its great what you can find online nowadays. For example, I have found several of the classics in pdf on Spiegelman's monster by Sol Spiegelman and Manfred Eigen from the 1960s-70s. (One of my interests is the RNA world and the role of retroelements in evolution.)
125349. Philippe Chantreau at 03:49 AM on 14 February 2010
        Is CO2 a pollutant?
        RSVP, your reference to Mars' atmosphere is obtuse. What are you trying to say? Mars' surface is warmer than it would otherwise be without its CO2 atmosphere. Earth benefits from the GH effect of CO2, water vapor and other gases. Obviously, if it had only CO2, it would be a lot colder, yet still warmer than space, so what exactly is your point? On this: "What would the world be like if everyone setup solar panels?". Solar panels actually trap solar radition that would otherwise reflect back into space my friend." Interesting idea. By all means, elaborate. That radiation actually would be relected only if it strikes a high albedo surface, which makes up little of the total surface and virtually none of the suitable areas for solar panel installation. So, in fact, it would heat up the surface and be re-radiated upward as IR. If instead that energy is captured, transformed and converted into various kinds of work, does it somehow add to the total energy? Will it somehow inject more heat into the system? Where will the "trapped" energy end up going, eventually?
125350. frankodwyer at 02:09 AM on 14 February 2010
        Medieval Warm Period was warmer
        "The Medieval Warm Period was warmer than current conditions. This means recent warming is not unusual and hence must be natural, not man-made." The argument is also logically invalid, even if the premise were true. Otherwise the following argument of the same form would be correct: 'The Black Death in the middle ages is estimated to have killed more of Europe's population than World War 2. This means that deaths during World War 2 were not unusual, and hence must be due to natural causes, not man-made'

Prev  2499  2500  2501  2502  2503  2504  2505  2506  2507  2508  2509  2510  2511  2512  2513  2514  Next