Written by Dr. Tim Ball
We recently published an article by Edward Hoskins entitled “The Junk Science Of A Supposed Climate Sensitivity Formula”. The author requested a review from PSI’s former chairman Dr. Tim Ball, which we pleased to be publishing below with extracts from the original article.
The diminishing influence of increasing Carbon Dioxide CO2 on temperature
The diminishing effect of CO2 on temperature
The temperature increasing capacity of atmospheric CO2 is small, but it is real enough.
The influence of CO2 concentration on temperature is known and widely accepted to diminish progressively as its concentration increases.
I understand that this is the generally accepted position about CO2 as greenhouse gas (GHG). I have yet to find or hear of any definitive proof that CO2 operates as a GHG, I have read much about rotating dipoles and other issues. I also heard the argument made some 20 years ago at a presentation in Calgary by a prominent skeptic that it was politically safer to say CO2 had a small greenhouse effect but it was so small as to be insignificant. I never agreed with this position and still don’t.
CO2’s effect diminishes logarithmically with increasing concentration. Both Global Warming advocates and Climate Change sceptics agree on this. IPCC Published reports, (TAR3), acknowledge that the effective temperature increase caused by growing concentrations of CO2 in the atmosphere radically diminishes with increasing concentrations.[i].
This information has been presented in the IPCC reports. However it is well disguised for any lay reader, (Chapter 6. Radiative Forcing of Climate Change: section 6.3.4 Total Well-Mixed Greenhouse Gas Forcing Estimate).
One of several deceptions about CO2 made by the IPCC to further their objective of proving their hypothesis is that CO2 is evenly distributed throughout the atmosphere. I knew that was wrong and was borne out by the recent results from the NASA satellite OCO2.
http://www.nasa.gov/mission_pages/oco2/index.html
Other deceptions included the residency time of CO2 in the atmosphere, to support their argument that even if we stopped production now the problem would persist for decades.
There are other deceptions but you get the picture.
This is a crucial fact. It is not acknowledged in the IPCC summary for Policy Makers.[ii].
The rapid logarithmic diminution effect is an inconvenient fact for Global Warming advocates and alarmists.
It is well understood within the climate science community.
It is certainly not much discussed.
This logarithmic diminution effect is the likely reason there was no runaway greenhouse warming caused by CO2 in earlier eons when CO2 levels were known to be at levels of several thousands parts per million by volume, ppmv.
The following simplifying diagram shows the logarithmic diminution effect using tranches of 100ppmv up to 1000ppmv and the proportional significance of differing CO2 concentrations on the biosphere.
