A New Geologic Age–Started by Us
At first, the thesis of this article, published in the January 28, 2008, issue of World Science, shocked me. But as I thought about it, it makes sense that the growing impact we humans are having on our planet has altered the planet so much that we have pushed the planet into a whole new geologic epoch. Scientists call it, aptly, the ‘Anthropocene.’
Jan. 25, 2008
World Science staff
A radical proposal is gaining ground among geologists: We have entered a new geologic time period on Earth, thanks to mankind’s own activities.We’ve so drastically changed the landscape through pollution and in other ways, it’s time to acknowledge the new “epoch” is here, a group of geologists writes Jan. 25 in GSA Today, a journal of the Geological Society of America.
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| An atlas published by the United Nations in 2005 showed through satellite images how various parts of the world have physically changed in the past two to three decades alone. These images show the mouth of China’s Yellow River in 1979 (above) and 2000 (below). A new peninsula in the lower image arises from sediment deposits from the river partly resulting from farming activity, U.N. experts say. (Courtesy U.N. Environment Programme)
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The new era would be called the Anthropocene, from the Greek anthropos (man) and ceno (new). “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,” the researchers said in an announcement of their proposal.The traditional name for our current epoch—soon to become the former one, if they have their way—is the Holocene. The Holocene has spanned the last 10,000 years and followed the Pleistocene, commonly called the Ice Age.The researchers at the University of Leicester, U.K. and the Geological Society of London said human impact on Earth is showing in many ways: changed erosion patterns; major disturbances to the carbon cycle; global warming; wholesale changes to plant and animal life; and ocean acidification.Although geology is mainly the study of Earth’s rocks, soil and physical structure—rather than animals and life forms as such—all these factors can ultimately influence that structure, researchers say. Man’s alterations to Earth are “stratigraphically significant,” the group said in the announcement.
The idea for recognizing a new geologic era isn’t new, though: Nobel Prize-winning chemist Paul Crutzen suggested it in 2002. The U.K. researchers’ work represented an attempt to further assess his proposal.
The group said their findings present the scholarly groundwork for consideration by the International Commission on Stratigraphy for formal adoption of the Anthropocene as the newest addition to the geological timescale.
Before the Holocene and preceding Pleistocene, the major era preceding that is called the Tertiary Period, from about 26 to 66 million years ago. That was when mammals largely took over the Earth from the by then-defeated dinosaurs. All these ages are considered part of a larger one, called the Cenozoic era. Before that was the Mesozoic, the age of dinosaurs; and still earlier, the Paleozoic, which saw the evolutionary explosion of the first animals. Everything before that is the “Precambrian.”* * *Send
