Euan Mearns, geologist: He takes a close look at the data on temperatures, carbon dioxide (CO2), and methane (CH4) found in the Vostok Ice Core of Antarctica. He focuses on the Eemian warm period between 130,000 and 115,000 years ago. This warm period was the last warm period before the current warm period, the Holocene. In her 2008 graphs showing the relationship between CO2 and temperatures from the Vostok Ice Core covering the entire record, Jo Nova stated the average lag was about 800 years, with temperatures rising (falling) about 800 years before CO2 rising (falling). This lag indicates that CO2 could not be the cause of rise or fall of temperatures.