The article says:
Schmitt said historical documents indicate average temperatures have risen by 1 degree per century since around 1400 A.D., and the rise in carbon dioxide is because of the temperature rise.It is difficult to see how Schmidt can be right in either of these claims.
The article is sloppy and doesn't say whether Schmidt is referring to Fahrenheit or Celsius degrees, but even if it's the former that would be a 6°F (3°C) degree increase in average global temperatures since the middle ages. I have never seen any scientific paper that shows anything like that, by a factor of at least 5.
Also, I thought it was well-established that the carbon dioxide being added to today's atmosphere by human activities is different than "natural" carbon dioxide by its carbon isotopes.
The AP article did not bother with any other opinions or appear to have fact-checked Schmidt's claim in the least. Nor did Tom Sharpe, the reporter at the Santa Fe New Mexican from which this article seems to have originated.
Could an MIT-PhD in geology really not know this? Or am I missing something?