New research led by the University of Bristol demonstrates that a decline in the concentration of atmospheric CO2 played a major role in driving Earth’s climate from a warm greenhouse into a cold icehouse world around 34 million years ago.
New research led by the University of Bristol demonstrates that a decline in the concentration of atmospheric CO2 played a major role in driving Earth’s climate from a warm greenhouse into a cold icehouse world around 34 million years ago. This transition coul
Between 40 and 34 million years ago, Earth’s climate underwent a major climatic transition. Before 40 million years ago, during the Eocene, Antarctica was covered by lush forests, but by 34 million years ago, in the Oligocene, these forests had been replaced by thick continental ice sheets, as we know Antarctica today. The main driver of this greenhouse to icehouse transition is widely debated, and little information is available about how climate changed on land. An international team led by Dr Vittoria Lauretano and Dr David Naafs at the University of Bristol used molecular fossils preserved in ancient coals to reconstruct land temperature across this transition.
The team used a new approach based on the distribution of bacterial lipids preserved in ancient wetland deposits. It was developed as part of the ERC-funded project, The Greenhouse Earth System (TGRES), which also funded this study. The TGRES PI and paper co-author Rich Pancost, from the University’s School of Chemistry, explained: ‘These compounds originally comprised the cell membranes of bacteria living in ancient wetlands, with their structures changing slightly to help the bacteria adapt to changing temperature and acidity. Those compounds can then be preserved for tens of millions of years, allowing us to reconstruct those ancient environmental conditions.’
Read more at University of Bristol
Image: Tree stomp in lignite deposits (Credit: Vittoria Lauretano)
d be partly reversed in the next centuries due to the anthropogenic rise in CO2.
