Humans Force Earth into New Geologic Epoch
By Robert Roy Britt, LiveScience Managing Editor
http://www.livescience.com/environment/080127-new-epoch.html
Humans have altered Earth so much that scientists say a new epoch in
the planet's geologic history has begun.
Say goodbye to the 10,000-year-old Holocene Epoch and hello to the
Anthropocene.
Among the major changes heralding this two-century-old man-made epoch:
Vastly altered sediment erosion and deposition patterns.
Major disturbances to the carbon cycle and global temperature.
Wholesale changes in biology, from altered flowering times to new
migration patterns.
Acidification of the ocean, which 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.
Vivid metaphor
In the February issue of the journal GSA Today, a publication of the
Geological Society of America, Jan Zalasiewicz and Mark Williams of
the University of Leicester and colleagues at the Geological Society
of London argue that industrialization has wrought changes that usher
in a new epoch.
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. (The term "age" is sometimes used
interchangeably with "epoch" or to indicate a transition period
between epochs.)
As an example, they said, agriculture in Africa "has so degraded
regional soil fertility that the economic development of whole nations
will be diminished without drastic improvements of soil management."
"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
U.S. Department of Agriculture, the Andrew W. Mellon Foundation.
Origin of a term
Earth's 4.5-billion-year history is divided into major eras, then
periods and finally epochs. The Holocene Epoch began after the last
Ice Age.
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; cene = new) back in 2000.
That year, Crutzen and a colleague wrote in the scientific newsletter
International Geosphere-Biosphere Programme about some of the dramatic
changes:
"Urbanization has ... increased tenfold in the past century. In a few
generations mankind is 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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then you are a tool of Capitalist interests. If you disagree with the theories
or dogmas of Catastrophic Anthropogenic Global Warming then you are a tool of
Capitalistic interests. Notice a pattern here? -- Captain Compassion
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Joseph R. Darancette
daranc@NOSPAMcharter.net
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