Prev  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  Next

Comments 276 to 300 out of 626:

276. Bob Armstrong at 10:31 AM on 20 April, 2009
     Scanning the above , a lot is excessively complex . Simple application of Stefan-Boltzmann and Kirchhoff shows the mean temperature of the earth will inevitably be about 1/21st the effective surface temperature of the sun . It's average albedo has no effect . See http://cosy.com/Science/TemperatureOfGrayBalls.htm . The implementation there needs to be extended to colored spectra , but its highly unlikely the couple of skinny spectral lines of CO2 , particularly when multiplied by the small portion released by man , relative to the already highly saturated base , has virtually any detectable effect . In any case , this analysis produces experimentally falsifiable numbers . I have never found an experimental demonstration of the purported "greenhouse" effect . Of course , plants being almost totally CO2 + H2O love that extra 3% man released from that sequestered in geologically lush ages . There is no question the planet is greener for the CO2 we are returning to the atmosphere .
277. Gord at 16:46 PM on 20 April, 2009
     AGW Theory: 1. VIOLATES the 2nd Law of Thermodynamics. 2. VIOLATES the Law of Conservation of Energy. 3. VIOLATES Electromagnetic Physics. 4. VIOLATES the Stefan-Boltzmann Law 5. VIOLATES Heat Radiation Physics. 6. VIOLATES Vector Mathematics. 7. VIOLATES Actual Measurements. 8. VIOLATES Cause and Effect logic. Further, despite over $50 Billion having been spent on AGW "research" and literally thousands of papers produced on the subject: - There is not even ONE Law of Science that supports AGW. - There is not even ONE measurement that shows that atmospheric CO2 can heat the Earth. ----------- "In academia and science, fraud can refer to academic fraud – the falsifying of research findings which is a form of scientific misconduct – and in common use intellectual fraud signifies falsification of a position taken or implied by an author or speaker, within a book, controversy or debate, or an idea deceptively presented to hide known logical weaknesses." http://en.wikipedia.org/wiki/Fraud Forms of scientific misconduct include: fabrication – the publication of deliberately false or misleading research, often subdivided into: - fabrication – the actual making up of research data and (the intent of) publishing them - falsification – manipulation of research data and processes or omitting critical data or results Another form of fabrication is where references are included to give arguments the appearance of widespread acceptance, but are actually fake, and/or do not support the argument" http://en.wikipedia.org/wiki/Scientific_misconduct ------------- I think AGW Theory is fraudulent and the people who claim that AGW is factual are guilty of fraud and scientific misconduct because: 1. AGW is deceptively presented to hide known logical weaknesses. 2. AGW omitts critical data or results.
278. Patrick 027 at 04:59 AM on 21 April, 2009
     Gord - so you aren't going to talk to a physics professor? Too bad for you. Bob Armstrong - skinny spectral lines? Have you ever seen the CO2 spectrum? Satellites can and have measured the spectrum of radiation emitted by the Earth to space and both water vapor and CO2 take significant chunks out of the total energy from the surface (by hiding it underneath the cooler atmosphere, which radiates to space but with less power). CO2 does this significantly between about 12 and 18 microns; the effect at the tropopause is saturated near the center of this band but not at the edges; the tendency is for each doubling of CO2 (within a range that we are currently in) to reduce net outgoing radiation at the tropopause by nearly 4 W/m2; the climatic response to this forcing is for the troposphere and surface temperature to increase until the radiative balance is restored; feedbacks occur that make the process a bit complicated. The band of absorption by a gas consists of some or many absorption lines; in the absence of line spreading mechanisms, these would have little width and not have much effect over the whole spectrum; however, random molecular motions and collisions broaden each contributing line so that they can form an absorption spectrum with peaks and valleys, but with significant absorption occuring even in the valleys. Unless the total C content of the biosphere and ocean are changing, the large C fluxes between those and the atmosphere must be balanced. The very small geologic outgassing rate also tends to be balanced by C sequestration by chemical weathering and organic C burial. There is a negative feedback that acts significantly over very long periods of time (generally longer than glacial-interglacial time scales), changes in the sun, geological outgassing, and forced changes in chemical weathering and organic carbon burial caused by continental drift and the raising of mountain ranges, etc, cause climate changes that tend to (depending on geography) change the chemical weathering rate in a compensating way (it may also change the organic carbon burial rate, though not necessarily in a compensating way (?), and also depending on geography); a long-term equilibrium climate occurs when the chemical weathering rate and organic carbon burial rate together balance the geologic outgassing rate. The biologic portion of the C cycle (any portion of it) will also be affected over many millions of years by biological evolution. The glacial-interglacial variability on the 20,000 to 100,000 year time scale is likely caused by Milankovitch cycles; not so much by changes in global annual average radiative forcing, but by large latitudinal and seasonal redistributions of solar heating, which, when certain thresholds are exceeded in one or the other directions (won't be the same value in both directions), can favor ice sheet formation and growth, or ice sheet decay and disintegration. The climatic response involves globally-averaged positive feedbacks - in particular, the positive albedo feedbacks of snow and ice, with some contribution from vegetation and aerosol changes, and also a positive greenhouse gas feedback from changes in CO2 and a couple other gases (and of course the faster-acting feedbacks that are involved in all climate changes, including water vapor). The precise mechanisms of the greenhouse feedbacks is not fully understood, but is understood to exist based on the robust correlation between greenhouse gas concentrations and climate on the glacial-interglacial time scale. Changes in atmospheric CO2 on this time scale can be caused by redistribution of C among the atmosphere, biomass, soil, upper ocean, and deep ocean; one potential factor is an increase in biological C sequestration from the upper ocean (which will then take CO2 from the atmosphere); this doesn't necessarily involve a large increase in geological sequestration because organic C precipitating from the upper ocean may be oxidized in the deep ocean; however, it will then be stored in the deep ocean until currents transport it upward - thus C storage in the ocean depends on the locations of biological C uptake relative to oceanic circulation patterns, and both can change in response to climate. Changes in oceanic pH caused by changing CO2 concentration can be buffered by dissolution of carbonate minerals and, generally over longer time periods, by the supply of dissolved elements by chemical weathering. Human activity has caused most if not all of the increase in CO2, CH4, CFCs, and if I'm not mistaken, N2O, over the last couple centuries. A majority, especially recently, is from the burning of fossil fuels - effectively an artificial acceleration (by well-over an order of magnitude) of geological outgassing. Some is also from cement production, and some (especially farther back in time) is from deforestation. This has occured significantly faster than glacial-interglacial changes in atmospheric composition and has gone outside the range of the variations over at least the last several hundred thousand years. The CO2 increase has been too rapid for oceanic pH buffering. There have been and are still some addtional uptakes, by oceans and biomass, of CO2 in response to the anthropogenic emissions; however, they are only a portion of the anthropogenic flux, so atmospheric CO2 has and is still increasing. There are limitations to how much more CO2 can be taken up from the atmosphere over a given time scale (limits to much more can the mass of C in biomass and soil increase, and limits on oceanic uptake because of oceanic chemistry and the limited rate of water exchanged between the upper and deep ocean), and climate change itself has the potential to reduce if not reverse these additional uptakes of CO2 from the atmosphere (as well as adding more CH4). Rapid and large changes into relatively unfamiliar conditions (unfamiliar as gauged by how long ago such conditions last occured) put stresses on ecosystems (even when species migrate or adapt, they may do so at different rates or in different ways - for example, the change in the activity of pollinators may not match the change in the plants whey would pollinate; also, different plant species will not respond the same way to CO2 changes and their response can be limited by other conditions - this is of relevance to agriculture) and can cause extinctions over and above the background level, up to the point of mass extinctions. Ecosystems are even more vulnerable if they are already under other stresses - such as habitat destruction and disintegration. If ecosystem stresses cause deforestation faster than aforestation (which is likely for a rapid climate change), then this could be an additional CO2 feedback. A CO2 sink will eventually materialize when boreal forests advance northward to replace tundra, although that will also be a positive albedo feedback. Human culture, including the economy, including infrastructure and farming, constitute an ecosystem - certainly one which can evolve in at least some ways much faster than any 'natural' ecosystem. However, an imposed change that requires adaptation will not be without costs. Soil does not migrate very fast. As with plants in general, some crops are photoperiod sensitive and so cannot simply be moved to follow temperature and moisture without additional breeding or loss of productivity. Temperature in not the only limiting factor in the growing season, and tropical conditions are not kind to many valued food crops. While some regions may experience increased agricultural productivity at first, this is only up to a point beyond which further climate change will reduce productivity, and this also tends to apply more to regions which already have enough food (for now). There are also biological ecosystem services, such as free pollination, that must be acknowledged (as well as natural pest control - biotic and abiotic factors apply). It is naive to expect global warming and CO2 increases to result in dependable bumper crops world-wide. The regular availability of fresh water resources - not just for agriculture - is of great concern in some regions. Warming also increases risk for some tropical diseases. It has been said that winter is our most effective public health program (see later comment for reference**). Our buildings and other infrastructure are designed for conditions - when those conditions change, infrastructure will require remodeling. Of course, the full cost is reduced when accounting for maintenance that must be done anyway (and that infrastructure yet to be developed). But it will cost when people must migrate upward from sea level (a large fraction of the world's people have settled near sea level) and away from newly arid regions, and perhaps abandon an even larger fraction of homes in some places than would be otherwise justified to reduce river and urban flooding costs. There are concerns about severe weather (not just tropical cyclones - extreme precipitation events in general, perhaps among other things; although in some places, winter headaches (land and air travel problems and costs) will be reduced - but not when and where snow is replaced by ice). There is confidence that a doubling of CO2 will increase global average surface temperature by about 3 +/- 1 degree C or so. Some regional effects, including general poleward shifts in midlatitude storm tracks, with associated drying on the low-latitude edge of storm tracks and increasing precipitation at high latitudes, as well as a sea level increase (which will not stop at 2100 - there are long term effects), are expected with confidence. But some uncertainty remains in the global average changes and especially with associated regional effects. This uncertainty imposes some adaptation costs by reducing the ability to plan - although it may also have a benifit in discouraging use of climate as a weapon.
279. Patrick 027 at 05:18 AM on 21 April, 2009
     "It's average albedo has no effect . See http://cosy.com/Science/TemperatureOfGrayBalls.htm . The implementation there needs to be extended to colored spectra ," Earth's albedo at solar-dominated wavelengths is about 0.3. At wavelengths dominated by terrestrial emissions, it is closer to zero.
280. Patrick 027 at 06:42 AM on 21 April, 2009
     ... and the albedos of snow, ice, and clouds are much higher for solar radiation than for terrestrial radiation. The terms 'albedo' and 'albedo feedback' are generally assumed to refer to SW (shortwave; solar radiation) effects; for Earthly conditions, LW (longwave; terrestrial) radiation processes are dominated by emission and absorption with reflection/scattering playing only a minor role.
281. Patrick 027 at 09:11 AM on 21 April, 2009
     “The Geography of Poverty and Wealth” by Jeffrey D. Sachs, Andrew D. Mellinger, and John L. Gallup, Scientific American, March 2001, pp.70-75, http://www.earth.columbia.edu/sitefiles/File/about/director/documents/SCIAM032001_000.pdf p.74: "Winter could be considered the world’s most effective public health intervention."
282. Gord at 17:50 PM on 21 April, 2009
     Biased Science. These two words put together in a single phrase is an example of an oxymoron. Science that is biased does not follow the scientific method and cannot be considered to be science. --------------- Right from the IPCC website..... Mandate " Its role is to assess on a comprehensive, objective, open and transparent basis the latest scientific, technical and socio-economic literature produced worldwide relevant to the understanding of the risk of human-induced climate change, its observed and projected impacts and options for adaptation and mitigation." http://www.ipcc.ch/about/index.htm What does "human-induced climate change" mean? Does it include Naturaly occuring climate change like the VAST expanse of time before the "industrial revolution"....NO IT DOES NOT! Ignoring all the NATURAL Climate Changes that occured before the equivalent of a "Milli-second" in geological time that Man has populated the Earth is FRAUDULENT and, obviously, EXTREMELY BIASED! Did the NATURAL Climate Changes somehow DISAPPEAR?. The IPCC TOTALLY ignores ALL NATURAL CAUSES OF CLIMATE CHANGE....as their MANDATE indicates. They, absolutely, will NOT accept ANY Scientific paper on NATURAL CLIMATE CHANGE or ANY NON-HUMAN INDUCED CLIMATE CHANGE! HOW BIASED CAN YOU GET? ----------------- The IPCC cannot be, even remotely, viewed as a "scientific" body.
283. chris at 19:47 PM on 21 April, 2009
     Gord, your assertions that the radiative fluxes into, within and out of the Earth’s atmosphere/surface in some way oppose the 2nd Law of Thermodynamics and the conservation of energy, fundamentally fail in the light of real world measurements. For example, the downward longwave flux (324 Wm-2 in the Kiehl and Trenberth Fig 7 that you are arguing over), is not a “made up” or modelled value. The downward longwave IR flux from the atmosphere is directly measured from IR detectors at the surface[*,**] and many of the components of the radiative balance can be measured from satellites [***,****]. There is a vast scientific literature on this. I’ve dumped four papers at the bottom of the post in which these measurements are described, but there are dozens of these. There are major programmes underway to pin down measures of the individual components of the radiative balance in an attempt to make reliable quantitative determination of the Earth’s radiative energy budget (e.g. Google ERBE, CERES, ISCCP). Ideally, precise accounting will allow a detailed determination of the excess (“out of equilibrium”) forcing from the combination of enhanced greenhouse gases/atmospheric aerosols by direct measurement. This is far from easy since the net anthropogenic forcing is a smallish number of Wm-2, that is the residual from the summation of a set of large numbers (see figure 7 of Kiehl and Trenberth, urled above). These radiative fluxes DO exist; they are measured in the real world [e.g. *,**,***,****]. Thus the assertion that radiative fluxes of the magnitudes described by Kiehl and Trenberth oppose thermodynamic laws, fails as a hypothesis. It’s straightforward to show: (i) that the enhanced thermal energy in the Earth’s atmosphere/surface over that which corresponds to the calculated temperature (e.g. using the Stefan-Boltzmann relationship for the outgoing longwave flux), is not a violation of the conservation of energy, but is simply the result of the accumulation of energy in the climate system (largely due to the effects of greenhouse gases); (ii) that enhanced longwave radiative fluxes within the atmosphere are not only compatible with the 2nd Law of Thermodynamics, but are a necessary consequence of the accumulation of energy and enhanced temperatures that result. Judging by your intransigent response to Patrick’s straightforward explanations, it may be futile to go through my explanations of these phenomena according to my understanding (I might do so anyway!). However you should consider the possibility that if your opinions don’t accord with real world observations, that it is your opinions that are in error and not the real world… [*]R. Philipona et al. (2004) Radiative forcing, measured at Earth's surface, corroborate the increasing greenhouse effect Geophys. Res. Lett. 31, L03202. This shows that the downward longwave IR measured at the surface (in several sites in Europe) is similar to the value in the Kiehl and Trenberth review, that the downward longwave IR decreases with increasing altitude as expected from its source in the atmosphere, and that the evidence indicates that the downward longwave flux has undergone an increasing trend during the period of analysis. [**]F. Prata (2008) The climatological record of clear-sky longwave radiation at the Earth’s surface: evidence for water vapour feedback? Int. J. Remote Sensing 29, 5247–5263. Similar to above, except that the downward flux is calculated from the temperature and water vapour content from surface radiosonde data. A more widespread distribution of sites is analysed for downward longwave IR flux so that a distribution of location-specific downward longwave IR fluxes is determined. [***]N. G. Loeb et al. (2009) Toward Optimal Closure of the Earth’s Top-of-Atmosphere Radiation Budget Journal of Climate 22, 748–766. One of many papers describing satellite measurements of inwards and outwards radiation which describes radiative fluxes of the magnitudes described in Kiehl and Trenberth (urled above). [****]B. Lin et al. (2008) Assessment of global annual atmospheric energy balance from satellite observations J. Geophys. Res 113, D16114, “ditto” ….and so on….there’s lots and lots of scientific literature on these topics.
284. chris at 20:20 PM on 21 April, 2009
     re #295

     In any case , this analysis produces experimentally falsifiable numbers . I have never found an experimental demonstration of the purported "greenhouse" effect

     Bob, you're exactly right that the analysis of radiative fluxes in the Earth's surface, atmosphere, and the top of the atmosphere radiation balance and so on, produces experimentally falsifiable numbers. In fact these numbers are experimentally verifiable. The radiative fluxes can be determined by measurement using satellites, or from surface or atmospheric spectrophotometers. There are some examples of papers describing these analyses in my post just above (#302). As for experimental determination of the greenhouse effect, the measurement of radiative fluxes provides a pretty compelling experimental demonstration. To give one example, the Philipona paper cited in post #302 describes direct measurement of the downward longwave IR flux at the surface at several sites in Europe. The radiative flux at realtively low altitude sites (e.g. Locarno-Monti or Payerne in Switzerland) is around 320 Wm-2, which is close to the value in the Kiehl and Trenberth article that is being discussed in the latter part of this thread. There are a number of things about this study that gives us confidence that our understanding of the greenhouse effect is robust. (i) Theory of greenhouse gases and their effects on the Earth' temperature indicates that greenhouse gases in the atmosphere should absorb longwave IR emitted from the Earth's surface "converting" some of this energy into bond vibrational and kinetic energy in the atmosphere. The atmosphere should warm, and the atmosphere should radiate longwave IR with a magnitude consistent with its temperature. That's exactly what is measured in the real world. The downward longwave IR flux must originate from the atmosphere. The wavelengths/energies of this flux are not appropriate for direct solar irradiation. (ii) Since the downward longwave flux has its source in the atmosphere, one expects that as one goes to higher altitudes away from the Earth's surface, the downward longwave IR flux will weaken since it is originating from cooler parts of the atmosphere. This is exactly what is observed. Again looking at real world measurements, the large downward longwave IR (LWIR) flux measured at Locarno-Monti or Payerne,is a consequence of the relatively low altitude of these sites (below 500 metres). If one makes equivalent measures of LWIR at, say, Davos or Cimetta at altitudes near 1600 metres, the downward LWIR is closer to 280 Wm-2. This is just what one expects from a downward LWIR flux originating in the atmosphere. If this directly measure downward LWIR flux was originating elsewhere (e.g. the sun), it's magnitude should increase with altitude. (iii) The expectation from our understanding of greenhouse gases, is that enhanced greenhouse gas concentrations in the atmosphere will result in the "interception" of greater amounts of LWIR emitted from the Earth's surface, further slowing down emission of LWIR into space, and warming the atmosphere further. Of course once radiative balance is reestalished, the top of the atmosphere (TOA) fluxes will be in balance (total energy into the atmosphere for the sun more or less equals energy dissipated back into space). However we expect that the enhanced greenhouse gas concentrations (CO2 and water vapour), and enhanced atmospheric warming, will result in measurable increases in the downward LWIR measured at the surface. Again, the study by Philipona et al indicates that this is the case. Over the period of study the LWIR has increased (by a few Wm-2) at each of the 9 sites studied. That's just the results of one study. There are many analyses of this sort using surface, atmospheric and satellite measures of radiative fluxes.....it's all pretty much as expected from our understanding of the greenhouse effect.
285. Gord at 20:51 PM on 21 April, 2009
     Chris - One step at a time. Conservation of Energy first. Please answer these questions: 1. Do you agree that the Law of Conservation of Energy states "ENERGY CAN NEVER BE CREATED OR DESTROYED"? 2. Do you agree that the Sun is the ONLY energy source in the following paper (Fig.7)? 3. Do you agree that the Earth and the Atmosphere are NOT energy sources? Here is a link to Kevin Trenberth's paper: Earth’s Annual Global Mean Energy Budget 4. Do you agree that: Fig.7 of the Energy Budget shows: - Incoming Solar Energy, at the top of the atmosphere, to be 342 w/m^2 ? - Surface Radiation of the Earth is 390 w/m^2 ? 5. Is 390 w/m^2 greater than 342 w/m^2 ? 6. Where did the "extra" 48 w/m^2 come from? ------------------ This is about as obvious as it gets! There is a CLEAR VIOLATION of the Law of Conservation of Energy....BEYOND DISPUTE! If you are going to try and re-write or dis-prove the Law of Conservation of Energy or claim that measurements show that "energy was created"....forget it. It is a FACTUAL IMPOSSIBILIY! ----------------- I look forward to your response.
286. Gord at 21:27 PM on 21 April, 2009
     Chris - Your claims that the Back Radiation have been measured are correct, however "direct" measurements are only possible with instruments that have detectors that have been cooled far below the -20 deg C atmospheric average temperature. Example: Interferometers typically cool their detectors to 77 K (-196 deg C) or lower! These instruments work in support of the 2nd Law of Thermodynamics NOT in violation of the 2nd Law. "Direct" measurements of the Back Radiation are NOT POSSIBLE unless the detector is cooled below the atmospheric temperature. This is EXACTLY what the 2nd Law states. --- "Second Law of Thermodynamics: It is not possible for heat to flow from a colder body to a warmer body without any work having been done to accomplish this flow. Energy will not flow spontaneously from a low temperature object to a higher temperature object." http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/seclaw.html#c3 --- ALL MEASUREMENTS clearly show that the Back Radiation CANNOT heat the Earth. This is PROVEN by the Solar Oven measurements done by Physics Dept.of Brigham Young University, Utah. This is also verified by the "millions of solar ovens" all over the Earth that DO NOT PRODUCE ANY HEATING AT NIGHT! If the Back Radiation really reached the "warmer" Earth our energy problems would be over. The AGW "Scientists" claim that this Back Radiation caused the entire Earth to warm from -18 deg C to +15 deg C! Ever hear of any AGW "Scientist" ever promote this "Green Energy" source? It DOES NOT EXIST!....that's why!
287. Patrick 027 at 05:08 AM on 22 April, 2009
     chris - thanks for the coverage of actual measurements! Gord - your comments on the poynting vector of radiative fluxes demonstrate that you have some concept of basic arithmetic (P/A = e*sigma*T^4 - e*sigma*Tc^4 - or if the environment also has an emissivity ec less than 1, P/A = e*ec*sigma*(T^4 - Tc^4)). This makes your refusal to apply this arithmetic to Kiehl and Trenberth's diagram all the more comical. Even though your trusted "hyperphysics" website uses the term "net", and I also offered the possibility that "hyperphysics" might not consider all radiative fluxes to be heat fluxes (though they are energy fluxes), but only the net radiative flux to be THE heat flux (this seems a bit clumsy to me, but perhaps that is the official definition of "heat", in which case most of us (including you) use the term incorrectly - but we know what we mean, and a simple word substitution of radiant energy for heat would render all of my descriptions to be correct) - still, if you do not want to think of radiant fluxes in both directions, your own logic gave you an out - you could see that the backradiation from the atmosphere is the Tc term and the radiation from the surface is the T term, and put them into the formula that you did not disagree with, so as to find the total radiant cooling rate of the surface to the atmosphere and space. You could even reword the explanation of the greenhouse effect, that it does not 'heat' the surface, but rather reduces the cooling of the surface at a given temperature (thus building up 'heat' energy until the temperature is sufficient for the cooling rate by convection and radiation to balance solar heating - bearing in mind that the role of convection is such that the temperature at all levels from the surface to the tropopause will rise or fall in response to tropopause-level radiative forcing - with regional, seasonal, and diurnal variations in that pattern). But I gave up hope that you would ever get that. Still, I will correct you on this point: "The IPCC TOTALLY ignores ALL NATURAL CAUSES OF CLIMATE CHANGE....as their MANDATE indicates."..."They, absolutely, will NOT accept ANY Scientific paper on NATURAL CLIMATE CHANGE or ANY NON-HUMAN INDUCED CLIMATE CHANGE!"..."HOW BIASED CAN YOU GET?" Wrong. http://ipcc-wg1.ucar.edu/wg1/wg1-report.html The title of chapter 6: "Palaeoclimate" Not that *you*(Gord) will believe any of it, but you might want to browse through it anyway. Paleoclimatic evidence on various timescales supports overall climate theory as it is.
288. Patrick 027 at 09:19 AM on 22 April, 2009
     Gord - "Ever hear of any AGW "Scientist" ever promote this "Green Energy" source?"..."It DOES NOT EXIST!....that's why!" You are confusing all energy with useful energy. Up to a point, the backradiation from the atmosphere can be useful - for the purpose of keeping nights warmer than they otherwise would be. If you want to heat something and 'heat' is available at sufficient temperature, that 'heat' energy will have some usefulness. On the other hand, if you want to cool something off, having something with a sufficient lack of 'heat' energy will be useful. If you want (a net/ *THE*) flow of heat, you will need a temperature difference; if you need (a net/ *THE*) flow of heat out of an object at some cold temperature or into an object at some warm temperature, you need something with even lower or higher temperature. OR you can do work. Work is essentially energy without much entropy. Work can be diverted from the flow of heat from hot to cold up to the point that conserves entropy (at which point, heat flow is proportional to temperature at both the hot end and the cold end) - in a device called a heat engine. Based on conservation of entropy, the maximum fraction of heat flow at the hot temperature Th that can be converted to work by a heat engine is equal to 1 - (Tc/Th), where Tc is the temperature at the cold end of the heat engine - of course, an actual macroscopic device will tend to increase entropy at least somewhat during operation. The potential to do work from chemical reactions can be analysed using Gibb's free energy. Thermodynamic equilibrium in chemical reactions occurs when the Gibb's free energy of the system has been minimized, at which point forward and reverse reactions occur at the same rate. Altering conditions - changes in pressure or temperature - can shift thermodynamic equilbrium; chemical fluxes into or out of a system can push a system out of equilibrium - thus, doing work on a system, allowing heat to spontaneously flow where it could have done work in a mechinical heat engine, or supplying free energy by chemical fluxes, can thus drive a chemical system to do things... Gibb's free energy is useful for finding the electrical energy that may be produced by a chemical battery.
289. Patrick 027 at 09:29 AM on 22 April, 2009
     I stated that work is energy (more precisely, a flow of energy) without much entropy. Ideally, it would be described as energy with zero entropy. However, one can see that on the molecular scale, heat energy fluxes actually involve particles doing work on each other. But these transfers of work lack macroscopic organization except for the organization supplied by a temperature gradient (hence the ability to have a heat engine). One could imagine that many macroscopic devices that are doing work but not with much organization relative to each other would have some disorganization on an even larger scale, so I left the possibility of having some entropy associated with macroscopic work open. However, it is clear that, just as thermodynamic analysis of a system requires some definition of a system (and it's boundaries), the scale of that system affects the maximum scale at which organization could be considered. So on the scale of a device, work is energy flow with zero entropy.
290. Patrick 027 at 09:56 AM on 22 April, 2009
     A last ditch effort to explain why photons can be emitted by the atmosphere and absorbed by a warmer surface: With inspiration from Socrates, I'll just ask you questions. You seem to admit that it is possible for the atmosphere to emit photons, provided that those photons are absorbed by a cooler object (the sensors mentioned by chris). Question1: Assuming this is not a case of quantum entanglement (how could it be expected to be quantum entanglement?), how does the atmosphere 'know' that the sensor is cooler than the atmosphere when it emits a photon in the direction of the sensor? What happens when the sensor is underneath a surface with some warmer temperature (warmer than the atmosphere) that has holes in it and is rotating very rapidly over the sensor, so that photons only have a clear path to the sensor for intervals of some fraction of a second. If the photon were emitted from a height above the sensor of 300 m, it will take at least 1 millionth of a second to reach the sensor. How does the atmosphere 'know' when to emit photons toward the sensor to avoid hitting the rotating surface above it - consider that it might have a variable speed. What if the sensor is in space, halfway between the Earth and the Sun. The atmosphere emits a photon directed toward the sensor. It takes a little over 4 minutes to reach the sensor. But 2 minutes after emission, something goes wrong with the sensor and the sensor overheats. How does the photon avoid the sensor (and the Sun) - or how does the atmosphere 'know' in advance that the sensor will overheat and thus 'decide' not to emit a photon in that direction? Technically, your statements suggest that you would not believe that the atmosphere could emit photons toward a mirror (functioning as a mirror for the wavelength of photon involved), because that photon might then be absorbed by the atmosphere (and what if the atmosphere got just 0.00000000000000001 K warmer in the intervening millionths (or less, depending) of a second?) But suppose you would allow that to occur, having not been able to answer the previous questions. In that case: The lower troposphere, say air at 280 K, and the upper troposphere/lower stratosphere, say air at 220 K (exact values will vary with season, latitude, etc.) can both emit photons at the wavelength of 15 microns. Granted, the upper cooler air will emit fewer such photons and a smaller fraction of them will reach the surface, but a few will (if they can be emitted in that direction, to which I say yes). Cool a sensor to 250 K. How does that sensor 'know' that one photon is from the warmer lower troposphere (and so 'decide' to absorb it) and that an identical photon is from the cooler upper air (and so 'decide' to reflect it, or let it pass, or whatever)?
291. Patrick 027 at 10:01 AM on 22 April, 2009
     "However, one can see that on the molecular scale, heat energy fluxes actually involve particles doing work on each other." Or of course pass by each other - mass diffusion.
292. Gord at 17:49 PM on 22 April, 2009
     Patrick - Please do not direct any more posts to me. I am past the point of responding to your "opinions" that continually violate basic Laws of Science. I have covered this in my posts #285 and #290. I suggest that you take your own advice and talk to a Physics Professor.
293. Patrick 027 at 04:10 AM on 23 April, 2009
     I've done better than that. I've taken entire college courses - including one specifically about radiation in the atmosphere. Maybe you shouldn't post anything here at all.
294. Gord at 16:38 PM on 23 April, 2009
     Patrick - It's probably appropriate to disclose my qualifications at this time. I am a Electronics Technologist and Professional Electrical Engineer who has been practicing Engineering for over 30 years. For the last 20+ years I have been a Licenced Engineering Consultant that consults on communications technology that includes propogating Electromagnetic Fields. This includes AM/FM radio, TV Broadcasting, Microwave links, Satellite links, coaxial and fiber optic links and optical/laser communication links. Atmospheric phenomena plays an important part in communications systems design that involves propogating Electromagnetic Fields. My clients include many large Telecommunications Companies and Manufactures throughout North America, the U.K, and other countries. I have also consulted for multiple Governments as well as providing major communication system designs and consulting services for one Commonwealth Game and one Olympic Game. I have provided free consulting services for two additional Olympic Games. --- During my career as a Professional Engineer, I have never encountered any situation where fundamental Laws of Science have been violated. I have never heard of any Professional Engineer or Physicist that disputes these fundamental Laws of Science either. Even Non-professionals such as most high school graduates (who have gone through the academic program) have a good knowledge of these basic Laws of Science. You, however, seem to be in denial of these fundamental Laws of Science. You, even as a Non-professional amateur, should be aware that these Laws of Science are called LAWS for a reason. If you don't see this, I would recommend that you sue your previous teachers and ask for your money back.
295. Patrick 027 at 05:11 AM on 24 April, 2009
     Gord - I appreciate you sharing your background. What I suggest now is that your knowledge of physics may be specifically taylored to the applications in your field. How so? For example: The physcial laws of electromagnetism are the same everywhere for every purpose. But for specific applications or purposes, they may be presented in a different format or used to derive specific formulas for a category of situations. It has been said that the bumble bee violates the laws of aerodynamics. What is actually true is that the bumble bee violates laws that are specifically suited for much larger objects - airplanes. The most fundamental formulas of fluid dynamics are hard to work with; useful simplified formulas can be derived using approximations - these approximations will only be accurate or suitable for a subset of applications. --------- "You, however, seem to be in denial of these fundamental Laws of Science" You are still fixated on the idea that my explanations, and frankly, those of many, many others, somehow violate the laws of science. They DO NOT. Your understanding does seem to violate laws - laws of cause and effect - it seems to require that various populations of molecules modulate their behavior in anticipation of future events. In reality, the second law of thermodynamics is a natural consequence of the statistical tendencies of populations of objects. When molecules/atoms/particles have energy and there are energy transitions available, energy is sometimes transfered or converted. This is described by quantum mechanics. Some energy may be associated with some organized process. The bulk kinetic energy of a larger object, and the momentum associated with it. Mechanical waves. Planetary orbits. The magnetic fields of macroscopic magnets. Energy that is disorganized may be transfered by heat flow. It is internal energy. Individual events are random, but there is an overall structure to the probability of energy distribution and population distribution; over time, random processes tend to produce specific distributions, such as the tendency of gas molecules to fill space evenly, and the particular distributions of the population over different energies, velocities, etc., the equipartition of energy among available degrees of freedom (availability of quantized degrees of freedom will shift depending on the population of particles that have sufficient energy), and the distribution of photon energies among available energy transistions capable of emitting and absorbing photons. In the absence of boundaries, any given population of gas molecules will tend to spread out over time, filling a larger and larger volume. If, within boundaries, all sizable volumes are occupied with statistically identical populations of gas molecules, the populations spread into each others spaces with no macroscopic change. This is thermodynamic equilibrium. If one volume has more or less of one kind of molecule than another volume of the same size, then the random molecular motions will result in a large scale statistical tendency - effusion and diffusion - thermodynamic equilibrium will be reached when the density of the volumes and their compositions are all the same within margins of random error. If some external force pulls some or all of the gas molecules to one side of a chamber, than the thermodynamic equilibrium will involve either a compositional gradient and/or a density gradient. Likewise with heat flow, chemical reactions, etc. Within the confines of imposed conditions and kinetic barriers, etc, concentrations of energy, composition, or density, tend to spread out at some rate until some equilibrium distribution is reached. The equilibrium distribution can and oftend does involve and mass and energy flows in opposite directions - forward and reverse reactions, back and forth molecular motions, back and forth photon exchanges. The available energy - the potential to do work - the Gibbs free energy - these exist because a perturbation from equilibrium produces some organized tendency in one or another direction. The second law of thermodymics really describes an emergent property of physical properties - it works at another level different from such fundamental physical laws as gravity and relativity, electromagnetism, conservation of charge, mass and energy, momentum and angular momentum, etc.
296. Wondering Aloud at 00:05 AM on 25 April, 2009
     Just for the record Gord and Patrick; Physics professors aren't so darn sure either. Especially ones with lots of experience.
297. Quietman at 03:12 AM on 27 April, 2009
     Patrick Are you starting to see my issue with chris here? This is exactly what I tried to point out earlier. Those of us in non-theoretical sciences and professions follow the laws of thermodynamics to practical ends and know that they can not be violated. They simply can not be applied to open systems, ie. living things and the earth itself precisely because they are open systems. It's the reason that climate models do not work. ps I have been following you on various threads and this is really the only point that I can fully disagree with you on (other than your understanding of ENSO which I only disagree with you on root cause). Gord Overall I agree with you, especially about the IPCC but other as mentioned to Patrick above, he has some valid points. I want to thank both of you for a little more insight.
298. Quietman at 03:18 AM on 27 April, 2009
     ps I downloaded chapter 6: "Palaeoclimate" and will go over it carefully. I'll let you know if I see any discrepancies (Paleontology is my thing).
299. Quietman at 04:01 AM on 27 April, 2009
     Chapter 6 is essentially written for the layman, not much actual information, just speculation: [It is very likely that glacial-interglacial CO2 variations have strongly amplifi ed climate variations, but it is unlikely that CO2 variations have triggered the end of glacial periods. Antarctic temperature started to rise several centuries before atmospheric CO2 during past glacial terminations.] - page 435 [It is likely that earlier periods with higher than present atmospheric CO2 concentrations were warmer than present. This is the case both for climate states over millions of years (e.g., in the Pliocene, about 5 to 3 Ma) and for warm events lasting a few hundred thousand years (i.e., the Palaeocene-Eocene Thermal Maximum, 55 Ma). In each of these two cases, warming was likely strongly amplified at high northern latitudes relative to lower latitudes.] - ibid. "Antarctic temperature started to rise several centuries before atmospheric CO2 during past glacial terminations." from the first paragraph is accurate, the rest pure assumption based on Hansen's hypothesis. Overall the statements made in the entire PDF are based on the GHG hypothesis being factual as presented by Hansen. IF you accept his hypothesis the paper is somewhat accurate but really does not talk about paleoclimate, only the CO2 to temperature relationships and is accurate in places that no assumptions were made. What it actually indicates is that CO2 follows temperature and is powerless to stop natural cooliing. By not looking at WHY CO2 follows temperature they make a grave error and that makes the recommendations misleading. Temperature increases allow increased biomass, both flora and fauna. In warmer climate the increased biomass creates the increased CO2 by simply breathing. The higher the faunal population the higher the CO2. There is indeed a feedback loop buit it is fauna feeds flora then flora feed fauna and loops to increase biomass. There are no major extinctions caused by increased CO2. This is quite clear in the fossil record so it is not harmful to the planet. The event 34 million years ago was a rapid cooling that appears to involve cometary impact. There is a new publication coming out that is described here: Earth Under Global Cooling ScienceDaily (Apr. 9, 2009) — "Thirty-four-million years ago, Earth changed profoundly. What happened, and how were Earth's animals, plants, oceans, and climate affected? Focusing on the end of the Eocene epoch and the Eocene-Oligocene transition, a critical but very brief interval in Earth's history, GSA's latest Special Paper provides new answers to these questions." ... "multiple extraterrestrial bolide impacts, possibly related to a comet shower that lasted more than two million years, may have played an important role in deteriorating the global climate." ... I am looking forward to this book. It may clear thing up a bit, but then it may just muddy the waters even more.
300. Patrick 027 at 08:55 AM on 27 April, 2009
     More on the role of chemical weathering: http://www.scitizen.com/screens/blogPage/viewBlog/sw_viewBlog.php?idTheme=13&idContribution=286

Prev  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  Next

Post a Comment

Political, off-topic or ad hominem comments will be deleted. Comments Policy...

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.