A Null Hypothesis for CO2

Abstract

Energy transfer at the Earth's surface is examined from first principles. The effects on surface temperature of small changes in the solar constant caused by the sunspot cycle and small increases in downward long wave infrared (LWIR) flux due to a 100 ppm increase in atmospheric CO2 concentration are considered in detail. The changes in the solar constant are sufficient to change ocean temperatures and alter the Earth's climate. The surface temperature changes produced by an increase in downward LWIR flux are too small to be measured and cannot cause climate change. The assumptions underlying the use of radiative forcing in climate models are shown to be invalid. A null hypothesis for CO2 is proposed that it is impossible to show that changes in CO2 concentration have caused any climate change, at least since the current composition of the atmosphere was set by ocean photosynthesis about one billion years ago.