The Greenhouse Effect

2 Comments

1. Vince,
   Your first sentence is correct, but you are mistaken after that. You especially get off track with :

   "However, the earth inside can still be heated by the sun and the air can be warmed at its surface, but it cannot escape, so the atmosphere inside the greenhouse is warmer than the outside, The same effect happens inside a car with closed windows left in the sun."

   The point you miss is that water evaporation and surface heat transfer, followed by free convection up, are the controlling mechanisms to carry heat from the surface to higher altitudes. Partial radiation trapping does occur, and is a necessary component of the atmospheric greenhouse effect. However, it is the raising of the average altitude of radiation to space combined with the adiabatic lapse rate that is the mechanism to heat the surface. The location of the average effective source of the radiation to space is about 5 km. This, combined with the wet lapse rate of -6.5 C/km gives the 33 C excess surface temperature.

   You need to read the write ups by Al (G2) and myself (G1) to better understand the process.

   Reply

2. I have added my comment in red however this does not show therefore I am double bracketing my comment(( ))and removed the cartoons as most are irrelevant.

   G9. The Greenhouse Effect (Posted on March 4, 2011 by Dr. Ed)
   by Vincent Gray, NZ Climate Truth Newsletter No 262

   The greenhouse effect is caused by absorption of infra red radiation from the earth by trace gases in the earth’s atmosphere. (( What about the heat sink of O2 and N2 the primary gasses of the atmosphere?)) A greenhouse confines only a small part of the atmosphere, so the trace gas absorption is negligible.

   However, the earth inside can still be heated by the sun and the air can be warmed at its surface, but it cannot escape,(( this is incorrect)) so the atmosphere inside the greenhouse is warmer than the outside, The same effect happens inside a car with closed windows left in the sun. (( R.W. Wood proved in 1909 that the “greenhouse effect is confined space heating thus to apply this term to “heat confinement in the atmosphere is lunacy))

   The greenhouse effect was first clearly identified by John Tyndall (Heat as a Mode of Motion 1863). He showed that several trace gases in the earth’s atmosphere absorbed infrared radiation at discrete wavelengths, thus warming the atmosphere, ((this is wrong)) reducing the escaping radiation and increasing the radiation from the atmosphere to the earth, thus causing warming.

   ((The work of John Tyndall is repeatedly misquoted and while very accomplished was completely modified when one looks at the work of Niels Bohr and the Bohr model (1922-3)which states in simple terms that when any gas absorb any radiation it does not cause the gas to “heat” . Thus when the author or any writer claims that the absorption of IR by CO2 or any other gas cause the atmosphere to heat they are wrong. Now it is important to differentiate between “water vapor” a gas and the other two phases of water found in the atmosphere and on earth at all times-liquid and solid. There is no question that water the liquid and water the solid(snow and ice) heat when they absorb radiation just like the earth itself. This heat is transferred to gases by conduction and then moved around the atmosphere by convection and the winds of TIME>))

   Radiation consists of alternating electric and magnetic  field oscillations.. It is a form of energy and therefore complies with the First Law of Thermodynamics, the conservation of energy. It is, however, not subject to the Second Law of Thermodynamics which is concerned with the conversion of heat energy into mechanical energy. ((This is not correct. Mr. V Gray just failed Physics 101. Here are some statements of the Second Law.))

   ((The second law of thermodynamics is an expression of the tendency that over time, differences in temperature, pressure, and chemical potential equilibrate in an isolated physical system. From the state of thermodynamic equilibrium, the law deduced the principle of the increase of entropy and explains the phenomenon of irreversibility in nature. The second law declares the impossibility of machines that generate usable energy from the abundant internal energy of nature by processes called perpetual motion of the second kind.

   The second law may be expressed in many specific ways, but the first formulation is credited to the German scientist Rudolf Clausius. The law is usually stated in physical terms of impossible processes. In classical thermodynamics, the second law is a basic postulate applicable to any system involving measurable heat transfer, while in statistical thermodynamics, the second law is a consequence of unitarity in quantum theory. In classical thermodynamics, the second law defines the concept of thermodynamic entropy, while in statistical mechanics entropy is defined from information theory, known as the Shannon entropy.

   Read more: http://www.answers.com/topic/second-law-of-thermo…

   The first law of thermodynamics provides the basic definition of thermodynamic energy, also called internal energy, associated with all thermodynamic systems, but unknown in mechanics, and states the rule of conservation of energy in nature.

   However, the concept of energy in the first law does not account for the observation that natural processes have a preferred direction of progress. For example, spontaneously, heat always flows to regions of lower temperature, never to regions of higher temperature without external work being performed on the system. The first law is completely symmetrical with respect to the initial and final states of an evolving system. The key concept for the explanation of this phenomenon through the second law of thermodynamics is the definition of a new physical property, the entropy.

   A change in the entropy (S) of a system is the infinitesimal transfer of heat (Q) to a closed system driving a reversible process, divided by the equilibrium temperature (T) of the system.[1]

   The entropy of an isolated system that is in equilibrium is constant and has reached its maximum value.
   Empirical temperature and its scale is usually defined on the principles of thermodynamics equilibrium by the zeroth law of thermodynamics.[2] However, based on the entropy, the second law permits a definition of the absolute, thermodynamic temperature, which has its null point at absolute zero.[3]

   The second law of thermodynamics may be expressed in many specific ways,[4] the most prominent classical statements[3] being the original statement by Rudolph Clausius (1850), the formulation by Lord Kelvin (1851), and the definition in axiomatic thermodynamics by Constantin Carathéodory (1909). These statement cast the law in general physical terms citing the impossibility of certain processes. They have been shown to be equivalent.

   Clausius statement

   German scientist Rudolf Clausius is credited with the first formulation of the second law, now known as the Clausius statement:[4]
   No process is possible whose sole result is the transfer of heat from a body of lower temperature to a body of higher temperature.[note 1]
   Spontaneously, heat cannot flow from cold regions to hot regions without external work being performed on the system, which is evident from ordinary experience of refrigeration, for example. In a refrigerator, heat flows from cold to hot, but only when forced by an external agent, a compressor.

   Kelvin statement

   Lord Kelvin expressed the second law in another form. The Kelvin statement expresses it as follows:[4]

   No process is possible in which the sole result is the absorption of heat from a reservoir and its complete conversion into work.
   This means it is impossible to extract energy by heat from a high-temperature energy source and then convert all of the energy into work. At least some of the energy must be passed on to heat a low-temperature energy sink. Thus, a heat engine with 100% efficiency is thermodynamically impossible. This also means that it is impossible to build solar panels that generate electricity solely from the infrared band of the electromagnetic spectrum without consideration of the temperature on the other side of the panel (as is the case with conventional solar panels that operate in the visible spectrum).

   Note that it is possible to convert heat completely into work, such as the isothermal expansion of ideal gas. However, such a process has an additional result. In the case of the isothermal expansion, the volume of the gas increases and never goes back without outside interference.))

   ((Read more: http://www.answers.com/topic/second-law-of-thermo…

   Heat consists of kinetic and vibrational energy (measured by temperature) of the molecules of all substances above absolute zero of temperature.  Some of Its energy can only be transferred to another substance if that substance is able to take it, which means it must have a lower temperature. ((This is the Second Law of Thermodynamic))

   Radiation is quite different. Its energy is given by the Stefan/Boltzmann Law, and it  is proportional to the fourth power of the absolute temperature of the emitter  (except for special systems like fluorescent tubes or lasers) .

   When radiation is absorbed it either causes a change of orbit of the electrons in an atom or molecule or it gets dispersed as general kinetic and vibrational heat. In both cases the resulting additional radiation is emitted in all directions. Thus in both cases the radiation absorbed by greenhouse gases is partly reemitted upwards and partly downwards where it returns to warm the earth (( The problem is that it cannot be disguised from the IR being radiated from the O2, N2, or any other sources on Earth at the same Kelvin temperatures))

   By far the most important greenhouse gas is water vapour.(( This is Tyndall's statement see it is quoted at G3 The greenhouse gas effect does not exist)) Its concentration is, however, so variable in time and space that we are unable to obtain an accurate average value. but it is roughly  4000 parts  per million .

   The minor trace gases are carbon dioxide 380 parts per million, methane   0.00179 parts per million, nitrous oxide 0.0003 parts per million.

   So in order to find whether the greenhouse effect ((There is no experimental data that proves that the “greenhouse gas effect exists))is increasing or falling it is mainly necessary to study water vapour.

   This task is currently impossible. Weather stations routinely measure relative humidity, which is the ratio of concentration to the saturation value.

   It is the property important for human comfort. Such measurements are too sporadic and unrepresentative of the earth in general to be much use to find if there is a trend up or down.

   A sensible scientist would give up at once. However, climate scientists seem determined to try and pretend humans are harming the planet, so they decided to make an outrageous assumption. They assume that the average concentration of atmospheric water vapor is proportional to the temperature. There is no observational or theoretical evidence for this assumption.  Water vapour can then be called a “feedback” and left out of tables of greenhouse gases. They do not like to tell us that there is no way that they could find the average temperature of the earth, so it only applies to the “temperatures” “projected”  by models.

   Here is a profile of water vapour in the atmosphere measured at Lauder in the South island. It shows that most is close to the surface but that some sort of average is impossible.

   Here is a NASA map of the “column averages” over time, which shows that water vapour is mainly over warm places (the tropics).

   So, having tucked the problem under the carpet we are bombarded with the problems of the second greenhouse gas, carbon dioxide, one tenth the concentration of the main gas. It is mainly measured over the sea where they try to argue that it rises steadily.

   Here is a chart from Indonesia which shows CO2 is not all that steady, but perhaps is going up.
   But does it matter? Without more information on water vapour we will never know.

   Vincent Gray
   75 Silverstream Road
   Crofton Downs
   Wellington 6035

   ———————————————————
   Leonard Weinstein says:
   March 6, 2011 at 6:53 am
   Vince,
   Your first sentence is correct, but you are mistaken after that. You especially get off track with :

   “However, the earth inside can still be heated by the sun and the air can be warmed at its surface, but it cannot escape, so the atmosphere inside the greenhouse is warmer than the outside, The same effect happens inside a car with closed windows left in the sun.”

   The point you miss is that water evaporation and surface heat transfer, followed by free convection up, are the controlling mechanisms to carry heat from the surface to higher altitudes. Partial radiation trapping does occur, and is a necessary component of the atmospheric greenhouse effect. However, it is the raising of the average altitude of radiation to space combined with the adiabatic lapse rate that is the mechanism to heat the surface. The location of the average effective source of the radiation to space is about 5 km. This, combined with the wet lapse rate of -6.5 C/km gives the 33 C excess surface temperature.

   You need to read the write ups by Al (G2) and myself (G1) to better understand the process.

   ((To Leonard Weinstein : please look up the scientific meaning of “Adiabatic” and tell us how it can properly be applied to atmospheric conditions when the atmosphere is continually absorbing and radiating energy?

   Its about time you looked at G3 The greenhouse gas effect does not exist. The more times you repeat your reference to the “adiabatic lapse rate” the more I see a horse with blinders on racing down a tunnel to fall off a cliff at the end of the tunnel. ))

   Reply

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