Korta utdrag ur kursboken "Mathematical Simulation Technology"

2010-11-29 10:08  

Vi publicerar här några korta utdrag ur kursboken som skapat bråk på KTH. Utdragen är exempel på det innehåll som rör klimatberäkningar, och som inte ingår i den aktuella kursen i numerisk analys.

kapitel 13.1


...So there we stand now: We have using physics and mathematics estimated the crucial climate sensitivity to be certainly less than 0.5 C, which is not alarming at all. Pooh! But is our calculation correct? IPCC sends out an alarm by suggesting that the climate sensitivity can be 10 times bigger, apparently assuming very large positive feed-back.What is the truth? Your further studies will help to find the answer, from physical laws and numbers. Is global warming a real threat or only imagined? Only science and mathematics can give an answer. Politics and relgion cannot.  

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179.2 The Illusory Greenhouse Effect

The main message to the World and its leaders from the 2007 IPCC Fourth Assessment Report (AR4) is a prediction of an alarming climate sensitivity in the range 1.5 ? 4.5C, with a “best estimate” of 3C, as a result of a socalled greenhouse effect. The physics of this effect is claimed to have been identified and scientifically described by Fourier[3] (1824), Tyndall[10] (1861) and Arrhenius[1] (1896). An inspection of these sources shows a very simplistic rudimentary analysis with a only a simple model for radiation and no thermodynamics, which is the origin of the message of this article: The mathematics of the Fourier-Tyndall-Arrhenius greenhouse effect is dead, and never was alive! 179.2 The Illusory Greenhouse Effect 941 However, to confuse the discussion, the “greenhouse effect” is described with a misleading double-meaning: It is both the combined total effect of the atmosphere on the Earth surface temperature including both radiation and thermodynamics, and at the same time a hypothetical radiative effect of “greenhouse gases” including CO2 without thermodynamics. In this way the “greenhouse effect” becomes real, because it is the total effect of the atmopshere and the atmosphere undeniably has an effect, an “atmosphere effect”, while at the same time it can be linked to CO2 apparently acting like a powerful “greenhouse gas” capable of global warming upon a very small increase of 0.028%. The simplest version of the “greenhouse effect” is described by Stefan- Boltzmann’s Law Q = ?T^4 (SBL), which in differented form

dQ =  ?4T^3 dT = 4 (Q/T) dT  ~ 4dT

with Q ? 280W/m2 and T ? 288K, gives a climate sensitivty of about 1C by attributing a certain fictitious additional “radiative forcing” dQ = 4W/m2 to doubled CO2. Since the total radiative forcing from the Sun is not assumed to change, the additional radiative forcing is supposed to result from a shift of the “characteristic emission level/altitude” to a higher level at lower temperature caused by less radiation escaping to space from lower levels by increasing absorption by CO2. In this argument the outgoing radiation is connected to a lapse rate (decrease of temperature with increasing altitude) supposedly being determined by thermodynamics. With lower “characteristic emission temperature” at higher altitude the whole temperature profile will have to shifted upwards thus causing warming on the ground. This is the starting point of the climate alarmism propagated by IPCC, a basic climate sensitivity of 1C, which then is boosted to 3C by various so-called (positive) “feed-backs”. The basic argument is that since Stefan- Botzmann’s Law cannot be disputed as such, and because CO2 has certain properties of absorption/emission of radiation (light), which can be tested in a laboratory, the starting value of 1C is an “undeniable physical fact which cannot be disputed”. Even skeptics like Lindzen and Spencer accept it, and if skeptics believe something, then it must be true, right? But wait! Science does not work that way, science only obeys facts and logical mathematical arguments, the essence of the scientitific method, and let us now check if the basic postulate of a “greenhouse effect” with basic climate sensitivity of 1C can qualify as science.

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...In its popular form the basic IPCC climate sensitivity of 1C is claimed to come from a “greenhouse gas” ability of CO2 to “trap heat”, which is supposed to convince the uneducated. In its more elaborate form intended for the educated, it is connected to a thermodynamic lapse rate and characteristic emission level, in order to account for an effect of additional radiative forcing without change of total radiative forcing. Both forms are severely simplistic and cannot count as science.

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...Climate alarmism as advocated by IPCC is based on the assumption that radiation alone sets an initial lapse rate of 10C/km, which then in reality is moderated by thermodynamics to an observed 6.5C/km. Doubled CO2 would then increase the initial lapse rate and with further positive thermodynamic feedback it is by IPCC predicted to reach an alarming climate sensitivity or global warming of 3C. Climate alarmism skeptics like Richard Lindzen and Roy Spencer buy the argument of an intial rate of 10C/kmdetermined by radiation, but suggest that negative thermodynamic feedback effectively reduces climate sensitivity to a harmless 0.5C. We will argue that an initial lapse rate of g = 9.81C/km is instead determined by thermodynamics (and not by radiation) as an equilibrium state without heat transfer, which then in reality by thermodynamic heat transfer (turbulent convection/phase change) is decreased to the observed 6.5C/km, with the heat transfer balancing the radiative heat forcing. More CO2 would then require more heat transfer by thermodynamics and thus to a further decrease of the lapse rate rather than an increase. The atmopshere would then act like a boiling pot of water which under increased heating would boil more vigorously but not get any warmer. In short: If thermodynamics is the main mechanism of the atmosphere as an air conditioner or heat transporter, then CO2 will not cause warming, and IPCC climate alarmism collapses. We thus identify a basic difference between atmospheric heat transport by radiation (similar to conduction) and by thermodynamics of convection/ phase change. In radiation/conduction increased heat transport couples to increased lapse rate (warming). In convection/phase change increased heat transport couples to decreased lapse rate (cooling).

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Källa: Mathematical Simulation Technology, Johan Jansson and Claes Johnson 2010.

Anm. På grund av begränsningar i teckenuppsättning på webben redovisas inte alla tecken i ekvationer och formler ovan korrekt.

Mats Lewan


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