Carbon dioxide is the thermostat of Earth’s atmosphere. That was demonstrated by John Tyndall, a British physicist, in experiments done in his laboratory in the 1850s. Using a relatively simple apparatus he showed that infrared radiation (heat) passes through oxygen and nitrogen gases unimpeded, whereas carbon dioxide, even in low concentrations, absorbs heat. Light energy from the sun (a spectrum of wavelengths) passes to Earth’s surface with little absorption, bringing the energy that is transformed into heat at the surface. Carbon dioxide then traps it, hence the name “greenhouse gas.” Far more sophisticated research has been done since, but Tyndall’s work is fundamental.
It is with sadness and alarm I encounter people today who state “but carbon dioxide is just a trace gas” as a fundamental objection to the whole of climate science. Worse, otherwise respectable media publish such drivel, lending uncritical approval to misinformation and doubt. The basic science is irrefutable, repeatable by experiment. That is how science works. No amount of bloviation from people who missed out on a basic physics education can change that, but offering them an uncritical forum will endanger us all.
Jerry E. LeClaire