The Pettenkofer method and the atmospheric CO2 content of the late 19th and early 20th centuries.

Is atmospheric CO2 really increasing due to anthropogenic emissions of greenhouse gases?

Note: I am often asked if CO2 is actually rising and if it wasn’t higher in the recent past (early 20th century). I believe this likely refers to the chemical method of CO2 measurements that were conducted prior to modern techniques… so, I thought I would cover a bit of that here.

The Pettenkofer method…

The Pettenkofer method, named after Max von Pett…