Geologists from the University of Leicester are among four scientists- including a Nobel prize-winner -- who suggest that Earth has entered a new age of geological time.

The Age of Aquarius? Not quite -- It's the Anthropocene Epoch, say the scientists writing in the journal Environmental Science & Technology.

And they add that the dawning of this new epoch may include the sixth largest mass extinction in Earth's history.

Jan Zalasiewicz and Mark Williams from the University of Leicester Department of Geology; Will Steffen, Director of the Australian National University's Climate Change Institute and Paul Crutzen the Nobel Prize-winning atmospheric chemist of Mainz University provide evidence for the scale of global change in their commentary in the American Chemical Society's' bi-weekly journal Environmental Science & Technology.

The scientists propose that, in just two centuries, humans have wrought such vast and unprecedented changes to our world that we actually might be ushering in a new geological time interval, and alter the planet for millions of years.

Zalasiewicz, Williams, Steffen and Crutzen contend that recent human activity, including stunning population growth, sprawling megacities and increased use of fossil fuels, have changed the planet to such an extent that we are entering what they call the Anthropocene (New Man) Epoch.

First proposed by Crutzen more than a decade ago, the term Anthropocene has provoked controversy. However, as more potential consequences of human activity -- such as global climate change and sharp increases in plant and animal extinctions -- have emerged, Crutzen's term has gained support. Currently, the worldwide geological community is formally considering whether the Anthropocene should join the Jurassic, Cambrian and other more familiar units on the Geological Time Scale.

The scientists note that getting that formal designation will likely be contentious. But they conclude, "However these debates will unfold, the Anthropocene represents a new phase in the history of both humankind and of the Earth, when natural forces and human forces became intertwined, so that the fate of one determines the fate of the other. Geologically, this is a remarkable episode in the history of this planet."