A recent study carried out by the University of Louisiana at Lafayette has suggested that CO2 levels are higher today than they have been for the past 23 million years.

Led by Dr. Brian Schubert, the project researchers measured the relative amounts of two stable carbon isotopes using fossilised plants.

The research enabled them to calculate CO2 concentrations during the period the plants grew. 

As a result, the team produced a new record of atmospheric CO2 than spans 23 million years of uninterrupted Earth history.

The scientists also concluded that current CO2 levels can be traced to human activity and are increasing at a rate never seen before in geological history.

“There have been past time periods in Earth’s history where CO2 levels are both higher than today and lower than today,” Schubert explains.

“The difference, though, is that past changes in CO2 and climate usually happen over very long-time scales – thousands or millions of years.”

“The rise in CO2 that we’re seeing today is much, much faster.”