Science is recognising humans as a geological force to be reckoned with
THE here and now are defined by astronomy and geology. Astronomy takes care of the here: a planet orbiting a yellow star embedded in one of the spiral arms of the Milky Way, a galaxy that is itself part of the Virgo supercluster, one of millions of similarly vast entities dotted through the sky. Geology deals with the now: the 10,000-year-old Holocene epoch, a peculiarly stable and clement part of the Quaternary period, a time distinguished by regular shifts into and out of ice ages. The Quaternary forms part of the 65m-year Cenozoic era, distinguished by the opening of the North Atlantic, the rise of the Himalayas, and the widespread presence of mammals and flowering plants. This era in turn marks the most recent part of the Phanerozoic aeon, the 540m-year chunk of the Earth’s history wherein rocks with fossils of complex organisms can be found. The regularity of celestial clockwork and the solid probity of rock give these co-ordinates a reassuring constancy.
Now there is a movement afoot to change humanity’s co-ordinates. In 2000 Paul Crutzen, an eminent atmospheric chemist, realised he no longer believed he was living in the Holocene. He was living in some other age, one shaped primarily by people. From their trawlers scraping the floors of the seas to their dams impounding sediment by the gigatonne, from their stripping of forests to their irrigation of farms, from their mile-deep mines to their melting of glaciers, humans were bringing about an age of planetary change. With a colleague, Eugene Stoermer, Dr Crutzen suggested this age be called the Anthropocene—“the recent age of man”.
The term has slowly picked up steam, both within the sciences (the International Commission on Stratigraphy, ultimate adjudicator of the geological time scale, is taking a formal interest) and beyond. This May statements on the environment by concerned Nobel laureates and the Pontifical Academy of Sciences both made prominent use of the term, capitalising on the way in which it dramatises the sheer scale of human activity.
The advent of the Anthropocene promises more, though, than a scientific nicety or a new way of grabbing the eco-jaded public’s attention. The term “paradigm shift” is bandied around with promiscuous ease. But for the natural sciences to make human activity central to its conception of the world, rather than a distraction, would mark such a shift for real. For centuries, science has progressed by making people peripheral. In the 16th century Nicolaus Copernicus moved the Earth from its privileged position at the centre of the universe. In the 18th James Hutton opened up depths of geological time that dwarf the narrow now. In the 19th Charles Darwin fitted humans onto a single twig of the evolving tree of life. As Simon Lewis, an ecologist at the University of Leeds, points out, embracing the Anthropocene as an idea means reversing this trend. It means treating humans not as insignificant observers of the natural world but as central to its workings, elemental in their force.