Email 5149, Phil Jones, Sept 2004: "I reckon that you would have to go back to about 3500BC to find a warmer period"

Email 5149

From: Phil Jones [[2]mailto:p.jones@uea.ac.uk] Sent: 06 September 2004 14:18 To: Folland, Chris Subject: Re: GLOBAL OR NORTHERN HEMISPHERE TEMPERATURES IN HOLOCENE

Chris, Paleo reconstructions is just to AD 200. What we have said is that the late 20th century is the warmest period in the last 2000 years, so stretching it a bit back to AD 1. Late 20th century is a bit loose, but I take it to be the 1980s and 1990s. ...PS I reckon that you would have to go back to about 3500BC to find a warmer period.

Wait, what?  If CO2 drives climate, and if CO2 never exceeded 300 ppm until recently, why was it warmer in 3500 BC?

Global Warming - Future

In the past 600,000 years carbon dioxide has never exceeded 300 parts per million.