If you could take a look at Antarctica 40 to 50 million years ago, it wouldn’t be the icy white landmass commonly pictured now: According to a new study, its environment probably felt much like California.
Scientists think the new measurements of the conditions in Antarctica during the Eocene epoch, a time when Earth as a whole had higher carbon dioxide and greenhouse gas levels, will improve climate models that can predict future conditions.
“Quantifying past temperatures helps us understand the sensitivity of the climate system to greenhouse gases, and especially the amplification of global warming in polar regions,” study co-author Hagit Affek, an associate professor of geology and geophyics at Yale University, said in a statement.
The conditions were estimated by measuring isotopes in ancient fossils. These isotopes indicated that temperatures reached as high as 63 degrees Fahrenheit, averaging around 57 degrees.
“By measuring past temperatures in different parts of Antarctica, this study gives us a clearer perspective of just how warm Antarctica was when the Earth’s atmosphere contained much more CO2than it does today,” lead author Peter Douglas, a post-doctoral scholar at the California Institute of Technology, said in a statement. “We now know that it was warm across the continent, but also that some parts were considerably warmer than others. This provides strong evidence that global warming is especially pronounced close to the Earth’s poles. Warming in these regions has significant consequences for climate well beyond the high latitudes due to ocean circulation and melting of polar ice that leads to sea level rise.”
These findings were published this week in the Proceedings of the National Academy of Sciences.
Another study published in the same journal this week established a new technique to confirm the age of a 120,000-year-old sample of Antarctic ice. Scientists also think this dating technique — radiometric-Krypton-dating technique — will prove useful to reconstruct past climate conditions, leading to a better understanding for how and why the Earth goes in and out of ice ages.