INFLUENCE OF ATMOSPHERIC CARBON DIOXIDE

PART ONE   INTRODUCTION

      This analysis shows increasing the current levels of atmospheric CO 2 could have negligible effect on earth temperatures by an examination of the molecular physics governing the absorption of  the two frequencies  which carry 20%  of the total heat being radiated from earth surface to space.  This analysis is limited to the effect of CO2 and excludes any of the multitudinous factors which control  temperatures at different times and places  throughout the earth. In particular now the warming period of the last ice age is well advanced  with most of the above ground ice thawed and oceans at  about at their historical maxima and the 100,000 year freezing period can be expected.                            

            The earth like all other planets in the solar system must reject continuously to outer space  the heat as received from the  sun to maintain stable temperatures. In the case of the earth this would have been  about minus 15 deg C without the existence of the atmosphere containing water vapor with some  CO2 and methane which absorb and return a portion of the outgoing heat to earth. This returned heat has raised the earth surface temperature some 30 deg C to 15 deg C mainly from water vapor but  including   6 deg C from the presence of CO2.  A doubling of the CO2 level would increase it by under 1 deg C

                This analysis is  based on  engineering  science and can be verified by any physicist or engineer familiar with the behavior of molecular gases when subject to heat radiation as  in chemical analysis and spectroscopy.

         PART TWO       HEAT ABSORPTION   BY  ATMOSPHERIC  CO2
        
             CO2 molecules consist of a carbon atom bonded to two oxygen atoms which can vibrate either by stretching or by bending the atom chain when subject to electro magnetic radiation in two spectrum bands, one  centered on 4 microns and that between 13 and 17 microns. These together carry 20% of the total black body spectrum which at 280  deg Abs extends from 3 to  100 microns with a maximum  at 10 microns. The  total radiation carried is calculated by the Steffan Boltzman Law to be 340 watts per sq meter of which 20%  or 75   w/sq m can be absorbed by CO2  molecules. The incoming energy in these 2 bands excite the electron bonds from their ground state to  higher energy levels followed by an immediate return to the ground state with the emission of the whole of the absorbed energy. This  radiation is emitted in  random directions at the original frequency and is not true absorption but is more correctly described as attenuation followed by scattering  This is a simplistic description of a very complex mathematical  relationship involving quantum mathematics which has been developed over the last century. The action of CO2 spectra absorption Is described in a 9 page document produced by ULCA (htpp://chem..ulca..edu/ )and in science text books 

         PART  THREE   CALCULATION PROCEDURES

                    Radiant energy is absorbed when passing through gasses in accordance with the Beer Lambert Law which states   the attenuation of radiant energy by gasses as a logarithmic function of the partial pressure of the gas and the path length and was applied to give the emittance of CO2 in Table 4 sect 3.12 of the 1984 Fundamentals Volume published by ASHRAE, The American Society of Heating, Refrigeration and Air Conditioning  Engineers and is  confirmed by fig 4-13 of Professor H C Hottel’s section in Heat  Transmission  3rd edition, McAdam- McGaw Hill

.             Emittance = 0.9 + 0.6 x { Log (pp x rel dens) plus Log ( 2xL Ft}

   These relationship are used to calculate the  absorption  of radiation passing through          5000ft stages from ground level to 50, 000 feet with alternative CO2 partial pressures of .0004 and ..0008  corrected for air density at height..

            3 (a) AIR  DENSITY GROUND UP TO STRATOSPHERE

Stage Heights (‘000ft)   2.5   7.5   12.5   17.5   22.5    27.5    32.5   37.5   42.5   47.5 

Relative Air Density     .93   ..80    .67      58     .49     .41      .34     .28.     .23     .18 

 

           3(b)  RADIATION ATTENUATION AT  5000 FT  STAGES  for 385  ppm   CO2                                              

Stage  Absorption  %     20     20     19     19       18      18       17      17       16      16     -

Stage  Transmision.%    80     80     81     81       82      82       83      83       84      84                                                                   Progresive Trans  .          80     64     52     42       34      28       23      19      16      13

        Total absorption = 100  -   13   =    87 %  of  the 20%  absorbable  by CO2                          

                          

            3(c)  RADIATION ATTENUATION AT  5000 FT STAGES   for  800 ppm  CO2

Stage Absorption   %   ..24      24     23       23       22       22      21       21     20       20          Stage Transmission %    76      76     77      77       78       78      79       79      80       80

Progressive  Trans   %    76      58     44       279.234       26       20      16       13      10      

           Total absorption =  100 -  8   =  92 %   of the 20% absorbable by CO2                            

Progressive transmission after each stage is calculated by multiplying together the previous stages transmissions e.g   76x76x77----x 80x80  = 8%  transmitted (as above). .     

 

            3  (d)       TEMPERATURE RISES CAUSED BY   CO2   LEVELS

               In the case of a CO2 level of 385 ppm half the energy absorbed by CO2 is 

 .5 x .87 x 74 = 32 W/Sq m  i.e  9.4 % of the required nett radiation to space..This increases the surface radiation required to 372 W/sq.m  and 285.5 deg abs  to maintain the world temperature at 279deg Abs  which is a rise of 6.5 deg C.

              In the case of a CO2 level of 800 ppm  half the energy absorbed by CO2  is   

.5 x .92 x 74 = 34 w/sq.m. which is 9.2%  of the required nett radiation.which would increases the surface radiation required  to 374 W/sq.m  and 285.9 deg Abs to maintain the world temperature at 279.deg Abs which is a rise of 6..9 deg  C.

            The above figures are from the Steffen Boltzmann Law as follows;

       The 4th Root  of ( W/sq m divided by 5.6 )  gives Radiation Temperature (deg Abs)

PART   FOUR           PAST AND FUTURE WORLD TEMPERATURES

                   The world temperature of 15 deg C used above is a theoretical number to represent the balance point between solar input and rejection to space considering  the globe  as a whole. The actual temperatures vary over a range of 100 deg C at different places and times ranging from minutes to millennia. The major factors are due to the rotation of the earth ,variations in  its orbit, fluctuations in atmospheric water vapor and ocean temperatures  which have raised the bare globe temperature from minus 15 devagC  by 30 degC ..CO2 has contributed 7 degC  which would increase it by under 1 degC even if the present level of 385 ppm were  doubled to 800 ppm.

                      Over the last half million years the earth has experienced 4 Ice Ages during each of which  ocean  levels slowly fell over 100 meters in 100,000 years as ice formed above ground in the northern hemisphere  then rapidly melted in under 10,000 years. These cycles are confirmed by geological records from coral reefs and deep ocean deposits and other similar data. At present the last thaw has brought sea levels close to their recorded maximum with some above ground ice remaining only in Greenland and Antartica .The last 5000 years have  been consistently mild as the thaw continued but for  the next 100 000.year the slow freeze will slowly develop with colder northern winters and warmer tropical oceans evaporating moisture to be carried towards the polar areas.
 
PART   FIVE            GENERAL CONCLUSIONS

        CO2 has a negligible effect on earth temperatures which are controlled by the rotation and orbit of the earth and by fluctuations in atmospheric water concentrations.

The current concern is baseless and attention should be devoted to coping with normal and extreme conditions such as blizzards., floods, droughts, heat and cold  etc.