What Antarctica’s past reveals about future climate
Bella Duncan is researching Antarctica’s past climate between 25 million and four million years ago, which includes the Miocene and Pliocene geological epochs.
“I cover a big range of time, during which Antarctica went through some pretty massive changes in the behaviour of its ice sheets,” she says. “These were times when the ice sheets were often smaller and more dynamic than today.”
To work out what was happening many millions of years ago, Bella measures samples taken from Antarctica which contain biomarkers—fossilised molecules of once-living material—which she then analyses to reconstruct past climates.
“I’m trying to find out temperatures, get information about hydrological cycles and establish what vegetation was present—these things help to inform us about potential future thresholds in the climate system with current climate change.”
Bella says the history of Antarctica’s climate is enlightening. “What happens in Antarctica has a massive impact on the rest of the world, especially in terms of things like sea level, and it also plays a big role in ocean circulation and general climate. If we can establish what was happening with Antarctica’s climate in the past then that can tell us quite a lot about what the global climate was doing at that time also—for example, if there was ice in Antarctica then the global climate would have to have been cool enough to allow that.”
For more information contact Bella Duncan on 04-463 5233 ext 8373 or bella.duncan@vuw.ac.nz