AUG 05, 2021 10:02 AM PDT

Drop in CO2 Linked to Climate Change 34 Million Years Ago

WRITTEN BY: Annie Lennon

A decline in the concentration of atmospheric CO2 drove the Earth’s climate to change from warm to ice-cold around 34 million years ago. The corresponding study was published in Nature Geoscience by researchers from the University of Bristol in the UK and the University of Melbourne in Australia.

During the Eocene period 40 million years ago, Antarctica was covered with lush forests. However, 34 million years ago, these forests were replaced by the ice sheets we see today. Until now, there has been little knowledge on how the climate changed so drastically over this period. 

While sea surface temperature changes show evidence of long-term cooling, researchers need to know what temperatures simultaneously occurred on land to understand the reasons behind this cooling.

To visualize land temperatures during this period, researchers examined molecular fossils preserved in coals found in the southeast Australian Gippsland Basin. They used a new approach that analyzed the distribution of bacterial lipids.

These compounds, say the researchers, once made up the cell membranes of ancient bacteria and changed slightly over time to help bacteria adapt to changing temperatures and acidity levels in their environments. These lipids are particularly useful for researchers as they can be preserved for tens of millions of years. 

In the end, the researchers found that land temperatures cooled alongside those in the ocean by around 3C. Then, in climate model simulations, they found that only a decline in atmospheric CO2 could produce the same cooling effect as seen in the coals. 

“Our data form an important benchmark for testing climate model performance, sea–land interaction and climatic forcings at the onset of a major Antarctic glaciation,” wrote the researchers. 

Their data also provides further evidence of the crucial role atmospheric CO2 plays in regulating the Earth’s climate, as well as the formation of ice sheets. 

 

Sources: Nature GeoscienceScience Daily

About the Author
University College London
Annie Lennon is a writer whose work also appears in Medical News Today, Psych Central, Psychology Today, and other outlets. When she's not writing, she is COO of Xeurix, an HR startup that assesses jobfit from gamified workplace simulations.
You May Also Like
FEB 02, 2022
Plants & Animals
Part of California Redwood Forest Returned to Sinkyone Tribe
FEB 02, 2022
Part of California Redwood Forest Returned to Sinkyone Tribe
Save the Redwoods League, a non-profit organization dedicated to preserving redwood forests, has returned 215 acres of C ...
APR 18, 2022
Plants & Animals
Some Fish Species Can Count
APR 18, 2022
Some Fish Species Can Count
If someone asked you if fish could count, your response would probably be… probably not? Counting seems like an a ...
MAY 10, 2022
Earth & The Environment
Water scarcity predicted to worsen in more than 80% of croplands globally this century
MAY 10, 2022
Water scarcity predicted to worsen in more than 80% of croplands globally this century
Climate change is real and it’s happening literally right before our very eyes. These ongoing, observable effects ...
MAY 12, 2022
Cannabis Sciences
Resources For Growing Your Own Cannabis
MAY 12, 2022
Resources For Growing Your Own Cannabis
Resources for growing your own cannabis at home, including the science behind getting the best grows possible.
MAY 15, 2022
Earth & The Environment
This Day in Science: Mount St Helens Eruption Anniversary
MAY 15, 2022
This Day in Science: Mount St Helens Eruption Anniversary
Volcanic eruptions are some of the most awesome spectacles in nature, as watching the interior of the planet we live on ...
MAY 17, 2022
Plants & Animals
Broad International Cooperation Needed to Save Coral Reefs
MAY 17, 2022
Broad International Cooperation Needed to Save Coral Reefs
Coral reefs have long been a central focus of the impacts of climate change. We hear stories every other day, it seems, ...
Loading Comments...