Washington: Turns out, greenhouse gases were the main drivers of climate change 66 million years ago, providing insight into the causes behind long-term climate change.
Researchers at Purdue University stated that the changes in ocean circulation patterns were the drivers of cooling temperatures near the end of the Eocene 'hothouse' period, but some blamed the declining levels of carbon dioxide.
The Eocene Epoch is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era.
Climate change often has more intense effects near the poles than elsewhere on the planet, also known as polar amplification.
The synchronized evolution of tropical and polar temperature that were reconstructed can only be explained by greenhouse gas forcing.
"Our findings are uniquely compatible with the hypothesis that the long-term Eocene cooling was driven by greenhouse gasses. This greatly improves our understanding of the drivers behind long-term climate change, which is important in order to predict the development of future climate change," said Margot Cramwinckel, firth author of the paper.
The researchers also found that temperature change was more dramatic near the poles than in the tropics during the Eocene. Even though most of the period was extremely warm, leaving little to no ice near the poles.
The findings are published in the Journal of Nature.