The new name got some support right away, but its implications were very big and science moves at its own deliberate speed. We were still officially in the Holocene, the epoch that began 11,700 years ago when Earth emerged from the last Ice Age, until this Tuesday. That’s when scientists in the Anthropocene Working Group presented hard evidence that human activity has changed the geology, atmosphere and biology of our planet so much that it has entered a new geologic epoch known as the Anthropocene.
So the Holocene, that golden interlude of warm, stable climate in which humans started farming, multiplied their population a thousandfold and eventually created high-energy, hi-tech civilisations, is at an end. Our numbers and our powers are now so great that they will determine the climate and even the sea level.
“We are simply so big and so dominant that we now need to drive the vehicle,” said Johan Rockström, director of the Potsdam Institute for Climate Impact Studies. “We are the ones with the levers now. We are starting to understand how they work, but we are not using them, and it’s time to use them.”
Rockström is not actually advocating geoengineering here, but a number of other climate scientists have been driven to that conclusion by the accelerating changes in the climate system. As indeed was Crutzen himself, who first went public with a call for scientists to consider geoengineering options in 2006.
It had been a taboo topic until then, but Crutzen’s Nobel Prize gave him the standing to broach the issue publicly. And it all does go together: if human activities are inadvertently changing the atmosphere and the biosphere in dangerous ways, many of which we didn’t foresee, then maybe we should also be willing to intervene to stop or reverse those changes.
This may seem far removed from the declaration of a new geological epoch, but the name-change is all about perspective. It is a way of making people realise that we human beings are now the decisive influence on how the whole Earth System evolves, and that we must pay constant attention to our choices if we want a climate that we can tolerate.
In the meantime, the Anthropocene has a few more hurdles to cross before it is formally acknowledged as our new geological epoch, but they have found the “golden spike” that will serve as its defining natural phenomenon. It is Crawford Lake, a very deep limestone sinkhole not far from Hamilton, Ontario in Canada.
It’s the annual layers of sediment at the bottom of the little lake, undisturbed by currents because it is so small and deep, that contain the evidence of the huge changes wrought on the environment by human beings since the 1950s, most notably the sudden jump in plutonium (from atomic bomb tests) and “fly ash” from steel mills in Hamilton.
There’s also lots of plastic waste in the sediments, of course, but mercifully nobody was tempted to rename our time the Plasticine Epoch.
