"The ice that scientists have stated is hundreds of thousands of years old can be no more than a maximum of 650 years in age...If carbon dioxide was a massive 10% of the atmosphere 500 years ago and .0033% today, the ice cores would still show the highest carbon dioxide levels near or at the top of the ice"

An interesting issue with ice core data | Watts Up With That?

...Most of Greenland’s ice is of recent origin. Prior to the Little Ice Age, most of the areas where today’s core samples are taken, were not covered with ice. The ice that scientists have stated is hundreds of thousands of years old can be no more than a maximum of 650 years in age. Were it not so, farming would have been impossible in Greenland prior to the Little Ice Age.

The upshot of all this is that glacier ice cannot be reasonably used to analyze carbon dioxide abundance in the atmosphere over time as the upper layers of ice will always have more carbon dioxide than the lower layers, regardless of the actual atmospheric levels of carbon dioxide. If carbon dioxide was a massive 10% of the atmosphere 500 years ago and .0033% today, the ice cores would still show the highest carbon dioxide levels near or at the top of the ice. When scientists make claims about the atmospheric carbon dioxide on the basis of ice cores, ignore their claims as the “junk science” that they are.