Parametric Study

This parametric study shows how varying various components affect annual average earth temperature.  Temperatures calculated using ModTran and the methodology developed described herein.Parameters evaluated are different cloud covers and CO2 concentration.

Summary of results

  • doubling CO2 increases temperature 0.57 to 0.82C, depending on cloud cover
  • tripling CO2 increases temperature by approx. 1.07C
  • varying cloud cover average temperature increase on the effect of doubling CO2 yields an average temperature increase of 0.72C, with a standard deviation of 0.09C (13%)

The method of calculation and the units involved are described in the page “Compute Delta T”.  Units H1, H2, and Ta are also defined on that page.

Surface Temperature Increase, base 400 ppm CO2
1976 Std. U.S.Atmosphere
Final Condition  Heat to Space,w/m^2 by Increasing CO2, H1 = before, H2 = after
Albedo Emissivity ppm CO2 H1 H2 Ta, K k δT, C Cloud Conditions
0.3 0.97 800 235.47 233.27 255.8 0.8876 0.673 Stratus-strato cum. 0.66 to 2 km top
0.3 0.97 1200 235.47 231.98 255.8 0.8876 1.068 Stratus-strato cum. 0.66 to 2 km top
0.3 0.98 800 235.47 233.27 255.1 0.8853 0.673 Stratus-strato cum. 0.66 to 2 km top
0.3 0.97 800 258.58 255.75 261.9 0.9086 0.789 No Clouds
0.3 0.97 800 222.03 220.24 252.1 0.8746 0.581 Cumulus, 0.66 to 2 im top
0.3 0.97 800 221.28 219.52 251.9 0.8739 0.573 Alto Stratus, 2.4 to 3 km top
0.3 0.97 800 250.89 248.25 259.9 0.9018 0.758 NimboStratus, 0.16 to 0.66 km top
0.3 0.97 800 245.83 243.35 258.6 0.8972 0.727 2mm/hr drizzle, with Stratus
0.3 0.97 800 250.89 248.75 259.9 0.9018 0.615 5mm/hr light rain, with NimboStratus
0.3 0.97 800 250.89 248.25 259.9 0.9018 0.758 12.5 mm/hr rain, with with Nimbostratus
0.3 0.97 800 222.43 220.24 252.2 0.8750 0.709 25 mm/hr heavy rain, with Cumulus
0.3 0.97 800 235.47 233.27 255.8 0.8876 0.673 75 mm/hr extreme rain, with Cumulus
0.3 0.97 800 257.54 254.62 261.6 0.9077 0.817 Standard Cirrus
0.3 0.97 800 257.54 254.62 261.6 0.9077 0.817 Sub Visual Status
0.3 0.97 800 242.64 240.24 257.7 0.8942 0.713 NOAA Cirrus
0.3 0.97 800 258.58 255.25 261.9 0.9086 0.928 LowTRAN6
0.3 0.97 800 235.47 233.27 255.8 0.8876 0.673 Stratus-strato cum. 0.66 to 2 km top
0.724 Average, All Cloud Types, Doubling CO2
13% Standard Deviation

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