www.csua.org/u/kld -> news.yahoo.com/s/livescience/20080127/sc_livescience/humansforceearthintonewgeologicepoch
WnmfDxJJQCzvtEF/Y=YAHOO/EXP=1201558588/L=td40q0WTVvr83xETQI4Vvw dxRTfow0eeOBwABwEj/B=l5eqItGDJHg-/J=1201551388473471/A=4919452/R=0/* Say goodbye to the 10,000-year-old Holocene Epoch and hello to the Anthropocene.
threatens tiny marine life that forms the bottom of the food chain. The idea, first suggested in 2000 by Nobel Prize-winning chemist Paul Crutzen, has gained steam with two new scientific papers that call for official recognition of the shift.
Scientists of the future will have no trouble deciding if the proposal was timely. All they'll need to do is dig into the planet and examine its stratigraphic layers, which reveal a chronology of the changing conditions that existed as each layer is created. Layers can reflect volcanic upheaval, ice ages or mass extinctions. "Sufficient evidence has emerged of stratigraphically significant change (both elapsed and imminent) for recognition of the Anthropocene -- currently a vivid yet informal metaphor of global environmental change -- as a new geological epoch to be considered for formalization by international discussion," Zalasiewicz's team writes. The paper calls on the International Commission on Stratigraphy to officially mark the shift. In a separate paper last month in the journal Soil Science, researchers focused on soil infertility alone as a reason to dub this the Anthropocene Age. "With more than half of all soils on Earth now being cultivated for food crops, grazed, or periodically logged for wood, how to sustain Earth's soils is becoming a major scientific and policy issue," said Duke University soil scientist Daniel Richter. Richter's work was supported by the National Science Foundation, the US Department of Agriculture, the Andrew W Mellon Foundation. Origin of a term Earth's 45-billion-year history is divided into major eras, then periods and finally epochs.
As early as the late 1800s scientists were writing about man's wholesale impact on the planet and the possibility of an "anthropozoic era" having begun, according to Crutzen, who is credited with coining the term Anthropocene (anthropo = human; That year, Crutzen and a colleague wrote in the scientific newsletter International Geosphere-Biosphere Programme about some of the dramatic changes: "Urbanization has ...
exhausting the fossil fuels that were generated over several hundred million years." Up to half of Earth's land has been transformed by human activity, wrote Crutzen and Eugene F Stoermer of the University of Michigan. They also noted the dramatic increase in greenhouse gases and other chemicals and pollutants humans have introduced into global ecosystems. The epochal idea has merit, according to geologist Richard Alley of Pennsylvania State University. "In land, water, air, ice, and ecosystems, the human impact is clear, large, and growing,"Alley told ScienceNow, an online publication of the American Association for the Advancement of Science. "A geologist from the far distant future almost surely would draw a new line, and begin using a new name, where and when our impacts show up."
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This 'blue marble' image is the most detailed true-color image of the entire Earth to date, using a collection of satellite-based observations, scientists and visualizers stitched together months of observations of the land surface, oceans, sea ice, and clouds into a seamless, true-color mosaic of every square kilometer of Earth. A US intelligence satellite has lost power and could fall to Earth sometime in February or March, a government official said on Saturday.
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