Linked Life Data

11540918

Source:http://linkedlifedata.com/resource/pubmed/id/11540918

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1998-8-28
pubmed:abstractText
Climate is an important environmental parameter of the early Earth, likely to have affected the origin and evolution of life, the composition and mineralogy of sedimentary rocks, and stable isotope ratios in sedimentary minerals. There is little observational evidence constraining Precambrian climates. Most of our knowledge is at present theoretical. Factors that must have affected the climate include reduced solar luminosity, enhanced rotation rate of the Earth, an area of land that probably increased with time, and biological evolution, particularly as it affected the composition of the atmosphere and the greenhouse effect. Cloud cover is a major uncertainty about the early Earth. Carbon dioxide and its greenhouse effect are the factors that have been most extensively studied. This paper presents a new examination of the biogeochemical cycles of carbon as they may have changed between an Archean Earth deficient in land, sedimentary rocks, and biological activity, and a Proterozoic Earth much like the modern Earth, but lacking terrestrial life and carbonate-secreting plankton. Results of a numerical simulation of this transition show how increasing biological activity could have drawn down atmospheric carbon dioxide by extracting sedimentary organic carbon from the system. Increasing area of continents could further have drawn down carbon dioxide by encouraging the accumulation of carbonate sediments. An attempt to develop a numerical simulation of the carbon cycles of the Precambrian raises questions about sources and sinks of marine carbon and alkalinity on a world without continents. More information is needed about sea-floor weathering processes.
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
S
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0921-8181
pubmed:author
pubmed:issnType
Print
pubmed:volume
82
pubmed:owner
NASA
pubmed:authorsComplete
Y
pubmed:pagination
261-89
pubmed:dateRevised
2007-7-17
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Precambrian evolution of the climate system.
pubmed:affiliation
Department of Atmospheric, Oceanic, and Space Sciences, The University of Michigan, Ann Arbor 48109, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.