Climate change causes new 'epoch'

The Earth has entered a new geological epoch because man-made changes to the climate are having a dramatic and long-term impact on the land and the oceans, a study has found.

A team of geologists believes that humans have altered the Earth so much since the start of the industrial revolution that we are now living in a new epoch called the Anthropocene, which began when the previous Holocene epoch ended in about 1800.

The geologists have proposed that the new epoch should be formally recognised by the international body governing geological terms. "On our exploration of the evidence, there's potential justification for the use of the new term," said Jan Zalasiewicz, of the University of Leicester and chairman of the Stratigraphy Commission of the Geological Society of London. "The surface environmental processes of the Earth are sufficiently different from pre-industrial times that the Earth's geology has in fact changed."

The geologists believe that human activity over the past 200 years has transformed the worldwide patterns of sediment erosion and deposition, disturbed the carbon cycle and global temperatures, triggered a mass extinction of animals and plants, and has caused the acidification of the oceans.

Dr Zalasiewicz said the dominance of humans had physically changed the Earth so much that there was little justification for believing that we are still in the Holocene epoch, which began when global temperatures rose at the end of the last ice age about 10,000 years ago. The Anthropocene, meaning "human influenced", was coined in 2002 by the Nobel chemistry laureate Paul Crutzen.