What might the world look like in centuries to come as the Earth grows warmer?
One way to assess that is to examine the history of the planet for similar episodes.
Looking back over millions of years we can study periods when the Earth was quite different, when the continents and oceans were in different configurations and the climate was significantly warmer or cooler.
The late Early Cretaceous, roughly 125 to 105 million years ago, was a greenhouse world. Back then the atmosphere was humid and high in carbon dioxide, the oceans were warm and there was little or no continental ice. Oddly enough, though the climate then was much warmer than it is today, Victoria was one of the coldest places on the planet because it was close to the South Pole.
So what the situation here was like then is a guide for the future — not in Australia, but the current polar regions of the Northern Hemisphere.
This image is a visualisation of a summer’s day by a river bank for a group of dinosaurs 125 million years ago.
On a summer’s day in polar Australia the sun would shine nearly all day. As with polar regions today, the Cretaceous South Pole would be warmer in summer than during the long and gloomy winter.
The average annual temperature of the South Pole in that deep past was probably somewhere between freezing and 10 degrees Celsius.
Curation notes by: Thomas Rich, Curator of Vertebrate Palaeontology Museums Victoria and Stephen Poropat, Swinburne University with Kate Phillips, Senior Curator Science, Museums Victoria and Lucinda Horrocks, Wind & Sky Productions.