This is a continuation of the dissection of Dan Kuttner’s 11 points regarding the science behind AGW, anthropogenic global warming. Dan posted these on Facebook a few months ago, and he reposted them again this year. He challenges readers to answer his 11 points, and he has agreed to allow me to use his name. He says in a separate communication that this is not a prank and he considers these to be serious matters. Here is Dan’s point number 3:
How have other climate variables, such as the sunspot cycle and naturally produced gases including, but not limited to, CO2 been subtracted from the IECC climate model?
The first thing I had to do was to figure out what is the IECC climate model. “The IECC® is a model energy building code produced by the International Code Council® (ICC®). It is referred to as a “model” code because it was developed through a public hearing process by national experts under the direction of the ICC.
Dan may be confused here, since the IECC climate model is not a main driving force behind AGW science. But his question deserves some kind of answer, and here is mine.
Start with the data plot above. That shows global temperature changes compared to sun activity. The thing to note is that temperature change does not track solar activity, which is comparatively flat. Compare the solar activity plot to the CO2 plot from the Keeling measurements below. These measurements show a dramatic increase in CO2 levels since 1958, when the study began.
The final answer to Dan’s question is the effects of other factors are effectively subtracted out due to their being relatively constant during the study period. The only other greenhouse gas that has changed notably is methane, and it is recognized that methane introduced by human activity is contributing to global warming.