The Inconvenient Skeptic: The Comprehensive Guide to the Earth's Climate

by John Kehr

There was one global effect of Antarctica freezing over. That was the drop in the global sea level. The sea levels around the world dropped ~55m as the ice sheets in Antarctica developed 34 million years ago. The effect of the dropping sea level would have been felt around the world. Shallow seas over continental shelves would have disappeared and more land would have been above sea level. So severe was the global impact that the largest species extinction since the time of the dinosaurs occurred. Species that had been separated by oceans were free to colonize new continents much to the detriment of the slower and weaker species. This extinction is called the Eocene-Oligocene extinction (25). Sea level change, species extinction and radical change in the Earth's climate all naturally occurred as a side effect of the change that happened when Antarctica's climate changed. The global effect was significant enough that the time before Antarctica froze is called the Eocene epoch of the current era and the time after is called the Oligocene epoch. It was truly a global change that was caused by a long-term change in ocean currents. This is not to say that Antarctica has stayed the same for the past 34 million years. It has had many periods where glaciers and ice sheets grew, but it has also had many periods when the glaciers and ice sheets were shrinking. That is their natural behavior. For more than 20 million years Antarctica swung back and forth between periods of deep cold ...