Gentlemen,
The CO2 analysis's performed over the past 6 years have been able to discern the types of CO2. In other words, CO2 from fossil
fuel combustion has a different signature when put under a particular microscope (located in Colorado) as compared to naturally occurring CO2. In other words, as of 6 years ago, the scientific community can now quantify is concentration and mass, the mass of CO2 deposited as result of anthropogenic activity.