CO2 Highest in At Least 800,000 Years

As analysis of ice cores from the Antarctic continue, we have moved from the finding that GHG's in the atmosphere are at their highest concentration in 450,000 years to 650,000 years and now to 800,000 years. I believe the limit to this record is supposed to be around 900,000 years. Even though the antarctic ice sheet is older than that, the continent has been mostly ice covered for the last 15