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Thursday, March 19, 2009

Have Humans Created a New Epoch in the Planet's History? -A Galaxy Insight

Transportation_space_rocket_2 No one can realistically argue that humans haven’t dramatically transformed the face of the planet. But now scientists propose that humankind has so altered the Earth that that we have brought about an end to one epoch and entered a new age. They suggest humans have so changed the Earth that it’s time the Holocene epoch was officially ended. The new epoch of Earth’s history is being called the Anthropocene, meaning “man-made”.

Geologists from the University of Leicester, Jan Zalasiewicz and Mark Williams, and their colleagues on the Stratigraphy Commission of the Geological Society of London say that humankind has entered a phase where we are so rapidly transforming the planet that a new era has started. Duke University soil scientist Daniel Richter agrees. He says the dirt under our feet is being so changed by humans that it is now appropriate to call this epoch 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,” Richter said.

Zalasiewicz and Williams research, which appears in the journal GSA, states that, “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.”

Their study specifically identified human impact through phenomena which includes:

• Transformed patterns of sediment erosion and deposition worldwide
• Major disturbances to the carbon cycle and global temperature
• Wholesale changes to the world’s plants and animals
• Ocean acidification

The geologists analyzed the proposal made by Nobel Prize-winning chemist Paul Crutzen. In 2002 Crutzen suggested the Earth had left the Holocene and started the Anthropocene era due to the global environmental effects of increased human population and economic development.

The researchers show how the dominance of humans has so physically changed Earth that there is increasingly less justification for linking pre- and post-industrialized Earth within the same epoch, known as the Holocene.

The scientists said their findings present the scholarly groundwork for consideration by the International Commission on Stratigraphy for formal adoption of the Anthropocene as the youngest epoch of, and most recent addition to, the Earth's geological timescale.

Of course the implication of entering the Anthropocene epoch goes far behind designating a formal name. Richter says that there are many serious questions facing us at this moment in time during Earth’s long and colorful history.

“Society’s most important scientific questions include the future of Earth’s soil,” Richter added. "Can soils double food production in the next few decades? Is soil exacerbating the global carbon cycle and climatic warming? How can land management improve soil’s processing of carbon, nutrients, wastes, toxics and water, all to minimize adverse effects on the environment?"

The ground we walk on is a precious, life-sustaining resource. Richter says leading scientists are quite concerned, for example, about how agriculture in Africa has depleted regional soil fertility to the point that economic development of whole nations will suffer unless entire regions adopt drastic improvements in soil management. Since food production, trade and economic growth are increasingly interconnected in today’s world, perhaps it is time for Earth’s inhabitants to cultivate a more global, cooperative perspective on how we manage Earth’s resources as a whole.

"This is an old story writ large of widespread cropping without nutrient recycling, with the result being soil infertility," Richter said. "And agriculture is only part of the reason why soils are so rapidly changing. Expanding cities, industries, mining and transportation systems all impact soil in ways that are far more permanent than cultivation."

"If humanity is to succeed in the coming decades, we must interact much more positively with the great diversity of Earth's soils."

Posted by Rebecca Sato.

Original here

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