Venue: Life Sciences Building.
Date/Time: Saturday 16th December, 16.00–17.00
Ice in a greenhouse world - 60Ma and 2060
Dame Professor Jane E. Francis1
1British Antarctic Survey
The polar regions are the areas on Earth most sensitive to climate change, both in the past and today, as we are now seeing so clearly.
Evidence from fossil plants in Antarctic rocks confirms that during the geological past polar climates were much warmer than now, allowing temperate and tropical vegetation to thrive on Antarctica near the South Pole. This has led to the general view that the Cretaceous - Eocene world, 100-50 million years ago, was ice-free.
Was Antarctica really ice-free, even when the continent was over the pole and experienced dark winters? High resolution studies of Late Cretaceous and Paleocene (75-60 Ma) marine algae (dinoflagellate cysts), correlated with isotope evidence for cold climates during algal blooms, now suggest that seasonal sea ice - and even ice caps - existed on Antarctica while temperate floras lived on the coast.
CO2 levels were ~400 ppm at that time, much like today. Can the Late Cretaceous provide us with a vision of our future world?