Earth’s carbon dioxide levels 34 million to 45 million years ago were five times today’s levels, Yale University said Wednesday of an ancient sea algae study.
“Through the energy we consume, each of us makes a contribution to increasing greenhouse gasses, such as carbon dioxide and methane, in the Earth’s atmosphere,” said lead Yale researcher Mark Pagani.
“To understand the implications of these actions for the future, scientists look to the past to gain a better understanding of Earth’s climate system under high greenhouse gas conditions,” he said.
The National Science Foundation study, reported in Science Express, also noted the link between sharp drops in worldwide carbon dioxide levels 25 million to 33 million years ago and the rise of important food crops such as corn and sugarcane.
“The onset and stabilization of ice sheets at the same time as a decline in carbon dioxide illustrates the importance of atmospheric carbon dioxide as an agent of both climate and biological change,” Pagani said.
