Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ancient Relatives of Algae Yield New Insights into Role of CO2 in Earth’s Early Atmosphere

18.09.2003


Awareness of the global warming effects of carbon dioxide (CO2) is relatively recent, but the greenhouse gas has been playing a critical role in warming our planet for billions of years, according to University of Maryland geologist Jay Kaufman and Virginia Polytechnic Institute geologist Shuhai Xiao.


The microfossil that indicates high amounts of ancient CO2; in this image, it looks strangely like a human face.
Photo Credit: Shuhai Xiao at Virginia Polytechnic Institute



Their results, which provide the best evidence to date of the age of the Calvin cycle—the photosynthetic cycle by which plants convert light energy and CO2 into cellular tissue—will be published in the September 18 issue of the journal Nature.

The research was funded by the National Science Foundation (NSF), an independent federal agency that supports fundamental research and education across all fields of science and engineering, and by NASA.


"This research is solid indirect evidence of the very high level of atmospheric CO2 in an ancient time period," says Enriqueta Barrera, program director in NSF’s division of earth sciences.

Using samples taken from individual fossils of an ancient relative of algae, Kaufman and Xiao provide the first estimates of the concentration of CO2 in the atmosphere some 1.4 billion years ago. Their study results show that the CO2 concentration at that time was 10 to 200 times higher than today’s levels. The gas therefore likely played a major role in keeping Earth warm, and probably dominated over another greenhouse gas, methane, after the atmosphere and oceans became oxygenated between 2 billion and 2.2 billion years ago.

"The sun was not as luminous then so it did not provide as much light and heat as it does now," said Kaufman. "Our new findings confirm models of how much greenhouse gas was required to keep Earth’s temperature warm enough so the oceans didn’t freeze during this time."

The Proterozoic period—the time period examined by Kaufman and Xiao--began 2.5 billion years ago and ended 543 million years ago. Scientists think many of the far-reaching events in the evolutionary history of our planet occurred during that period, including the appearance of abundant living organisms (probably early single- and multi-celled organisms) and significant oxygen in the atmosphere.

One of the ocean-dwelling organisms producing oxygen during the later Proterozoic period was Dictyosphaera delicata, a microscopic plant not much bigger than the dot in the letter i. To estimate ancient levels of atmospheric CO2, Kaufman and Xiao measured ratios of two different forms, or isotopes, of carbon present in individual microfossils of this plant.

"It was a painstaking process to get individual organisms," Kaufman said. The scientists "were able to take a camel hair brush and, using one hair of the brush, pick up one of these microfossils, which had been removed from its substrate [rock] using hydrofluoric acid, which dissolves the inorganic minerals but not organic matter."

Numerous microscopic samples of fossilized cellular material were knocked out of each organism using high-energy beams of ions from an ion probe. The sample material was analyzed with a mass spectrometer to come up with the results reported.

Kaufman is known for his contributions to research indicating that Earth has been almost entirely covered in ice several times within the last billion years. Kaufman and other scientists believe that each of these "snowball earth" periods were ended by a warming of the Earth resulting from a buildup in the atmosphere of greenhouse gases, particularly carbon dioxide.

-NSF-

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering, with an annual budget of nearly $5.3 billion. NSF funds reach all 50 states through grants to nearly 2,000 universities and institutions. Each year, NSF receives about 30,000 competitive requests for funding, and makes about 10,000 new funding awards. The NSF also awards over $200 million in professional and service contracts yearly.

Cheryl Dybas | NSF
Further information:
http://www.nsf.gov/od/lpa/news/03/pr03101.htm

More articles from Earth Sciences:

nachricht The unintended consequences of dams and reservoirs
14.11.2018 | Uppsala University

nachricht Earth's magnetic field measured using artificial stars at 90 kilometers altitude
14.11.2018 | Johannes Gutenberg-Universität Mainz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Epoxy compound gets a graphene bump

14.11.2018 | Materials Sciences

Microgel powder fights infection and helps wounds heal

14.11.2018 | Health and Medicine

How algae and carbon fibers could sustainably reduce the athmospheric carbon dioxide concentration

14.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>