An international team of scientists studied weather patterns during the Eocene era (over 30 million years ago), when global temperatures were about 14 degrees warmer than they are now. They found that the effect of carbon dioxide on the atmosphere may be even stronger than previously thought. The study, which reveals the truth about climate vulnerability, is published in the journal Nature Communications.
The Eocene era began 56 million years ago and ended 34 million years ago. It was characterized by such a warm climate that tropical forests grew in Antarctica. During the Eocene, the climate became sharply colder, and the era ended with the transition to the ice age, which continues to this day. However, until now it was not clear how the levels of carbon dioxide in the atmosphere were associated with climate change.
The researchers analyzed the isotope composition of the fossil shells of ancient marine plankton deposited on the seabed in the Eocene. This made it possible to determine the content of carbon dioxide in the atmosphere of that time and correlate it with information on the cooling of the climate.
The climate has been found to be more sensitive to fluctuations in atmospheric carbon dioxide levels when it is characterized by warmer temperatures. Scientists are going to test whether current models, which are used to predict climate change in the future, predict such an effect.