Deep sea algae connect ancient climate, carbon dioxide and vegetation

June 22, 2005

Assistant Professor Mark Pagani in the Department of Geology and Geophysics at Yale and his colleagues mapped the first detailed history of atmospheric carbon dioxide between 45 - 25 million years ago based on stable isotopes of carbon in a National Science Foundation study reported in Science Express.

"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 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." The findings were based on calibration of carbon-containing compounds produced by ancient sea surface algae that were recently isolated in deep sea drill cores.

The data indicates that between 45 - 34 million years ago the atmospheric carbon dioxide level was up to five times greater than today, with a sharp decrease and then stabilization to near modern day levels between 34 - 25 million years ago.

During the early part of the Paleogene Period, from 65 - 34 million years ago, global climates were much warmer than today with very little ice present at the poles. The boundary of the Oligocene and Eocene Epochs 33.7 million years ago was marked by rapid global cooling and the formation of large continental ice sheets on the Antarctic.

"Before this study, the relationship between the global climate and the concentration of carbon dioxide in the atmosphere during the late Eocene and Oligocene was largely unknown," said Pagani, who is recognized for his reconstruction of past atmospheric carbon dioxide levels between 25 million and eight million years ago.

They also present intriguing evidence that the sharp drop in carbon dioxide level, between 33 - 25 million years ago, prompted the origin of economically important land plants that are sensitive to atmospheric carbon dioxide levels, 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.

Collaborators were Brett Tipple from Yale, James C. Zachos and Stephen Bohaty at University of California, Santa Cruz and Katherine Freeman at Pennsylvania State.

Citation: Science Express on line (June 16, 2005).

Source: Yale University


Rank 3 /5 (2 votes)
Tags

Relevant PhysicsForums posts

More news stories

Could Venus be shifting gear?

(PhysOrg.com) -- ESA’s Venus Express spacecraft has discovered that our cloud-covered neighbour spins a little slower than previously measured. Peering through the dense atmosphere in the infrared, the ...

Space & Earth / Space Exploration

created 22 hours ago | popularity 5 / 5 (7) | comments 8 | with audio podcast

Two new moons for Jupiter

Advances in technology have lead to the discovery of new planets outside of our Solar System, and now even new moons in our own backyard.

Space & Earth / Space Exploration

created 22 hours ago | popularity 4 / 5 (1) | comments 7

Mars Science Laboratory computer issue resolved

(PhysOrg.com) -- Engineers have found the root cause of a computer reset that occurred two months ago on NASA's Mars Science Laboratory and have determined how to correct it.

Space & Earth / Space Exploration

created 23 hours ago | popularity 4.7 / 5 (6) | comments 4 | with audio podcast

NASA sees wide-eyed cyclone Jasmine

Cyclone Jasmine's eye has opened wider on NASA satellite imagery, as it moves through the Southern Pacific Ocean.

Space & Earth / Earth Sciences

created 14 hours ago | popularity 3.5 / 5 (2) | comments 2

Clam fields found at deep, low-temperature Mariana vents

(PhysOrg.com) -- Scientists have marveled at the unusual life forms thriving at high temperature hydrothermal vents of the deep ocean.

Space & Earth / Earth Sciences

created 22 hours ago | popularity 4.3 / 5 (3) | comments 0 | with audio podcast


Anonymous knocks CIA website offline (Update)

The website of the Central Intelligence Agency was inaccessible on Friday after the hacker group Anonymous claimed to have knocked it offline.

New error-correcting codes guarantee the fastest possible rate of data transmission

Error-correcting codes are one of the triumphs of the digital age. They’re a way of encoding information so that it can be transmitted across a communication channel — such as an optical fiber o ...

Small modular reactor design could be a 'SUPERSTAR'

(PhysOrg.com) -- Though most of today's nuclear reactors are cooled by water, we've long known that there are alternatives; in fact, the world's first nuclear-powered electricity in 1951 came from a reactor ...

New power source discovered

(PhysOrg.com) -- Researchers at the Massachusetts Institute of Technology (MIT) and RMIT University have made a breakthrough in energy storage and power generation.

The power of estrogen -- male snakes attract other males

A new study has shown that boosting the estrogen levels of male garter snakes causes them to secrete the same pheromones that females use to attract suitors, and turned the males into just about the sexiest ...

Advanced power-grid model finds low-cost, low-carbon future in West

(PhysOrg.com) -- The least expensive way for the Western U.S. to reduce greenhouse gas emissions enough to help prevent the worst consequences of global warming is to replace coal with renewable and other ...