How do scientists determine how much CO2 was in the atmosphere thousands of years ago, and to what level of certainty are they able to perform these calculations?

Question

How do scientists determine how much CO2 was in the atmosphere thousands of years ago, and to what level of certainty are they able to perform these calculations?

In: Earth Science

Answer 1

Omg

It happened

My area of specialty!!!

I see lots of ice cores mentioned here. Definitely a method deemed reliable.

There are other methods, such as tree cores! Uses very similar measurements and all that. It has to do with molecular processes and enzymatic favoring of different isotopes (C, O, others). Those isotopic signatures remain in the molecular structure and can be quantified, along with other environmental factors, to build a fairly accurate representation of a “moment (grow season) in time”