Lessons from 4 million years ago

Dr Chris Brierley, UCL Geography In Spring last year, carbon dioxide concentrations passed 400 parts per million in the atmosphere — a level not seen since the Pliocene era (3-5 million years ago), and perhaps not even then. We know that the Pliocene was a warm world without glacial cycles, and that the climate of the tropical Pacific was also structurally different. This lecture discussed the causes and implications of this discrepancy.