Climate and Climate Change ATOC-230 Paleo-CO2 Bruno Tremblay Atmospheric and Oceanic Sciences

Note: non-linear y-axis Geological Time Note: non-linear y-axis Age of the Earth: 4500 million years

Atmospheric CO2 Concentrations Keeling Curve (instrumental record)

Back to the Early Miocene (20 Ma) Today: 380 ppm

Almost Back to the Cretaceous (~ 65 million years) Higher carbon dioxide levels than today ? Today: 380 ppm

Phanerozoic Carbon Dioxide New York Times, November 06, 2006: In Ancient Fossils, Seeds of a New Debate on Warming

Ice Core Location Vostok

Ice Core  Same principles as for d18O

CO2 Record from Vostok Inter- glacial Glacial Blue curve: proxy data for CO2 from air bubbles trapped in the EPICA ice core