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 NASA looks to solar eclipse to help understand Earth's energy system
21.07.2017 | NASA/Goddard Space Flight Center

nachricht Scientists shed light on carbon's descent into the deep Earth
19.07.2017 | European Synchrotron Radiation Facility

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>