Over at wattsupwiththat.com, Clyde Spencer has a definitive essay detailing all the known knowledge of earth’s temperature and the factors that influence it. He shows that there is little the lock down of industrial economy will achieve as far as reduction in anthropogenic CO2 is concerned, even if it is taken that increase in CO2 in the atmosphere may influence earth’s temperature. Of course, the two decade long constant Global temperature means that there is little connection between atmospheric CO2 and Global temperature.
“Unless you have been in cryogenic suspended animation for several decades, you are aware of the extreme polarization about the role that CO2, particularly from burning fossil fuels, assertedly plays in warming the planet. I will attempt to provide a fresh perspective on the issue below.
It seems that many people think of global circulation models (GCMs) as being a virtual reality, or at least some kind of scientific ‘truth.’ What is generally unappreciated is that the GCMs are, instead, complex and convoluted working hypotheses. As such, they are a part of the Scientific Method. However, they should be subject to careful scrutiny, evaluated against reality, and modified as appropriate to conform to reality. That is the essence of the Scientific Method! Any hypothesis that does not have utility as an explanation, or have reliable predictive powers, does not achieve the purpose of scientific theories.
The extant GCMs, while purporting to work from first principles, have widely varying predictions of future temperatures, and are generally contradictory in their predictions of future precipitation patterns. Projections fail to mimic the step-like behavior of past, recent temperature increases. They gave no prediction of the current plateau in average global temperatures, nor do they provide an acceptable explanation for the current temperature plateau. The only thing that they have in common is an upward trend, not unlike CO2, or even the general population growth. Clearly there are problems with the computer models! Apparently, basic assumptions about the relationships of feedback loops add an element of subjectivity that nullifies the goal of operating from first principles. There are other more technical criticisms of the GCMs, but I won’t go into them here. As long as all the modelers assume that CO2 is driving temperature increases, one can expect that the models are going to display that behavior because CO2 is increasing. If I were to buy a high-performance car, based on computer simulations of similar veracity, I’d ask for my money back.” (from the essay)
Read the whole essay here.