Welcome to the Anthropocene

Tuesday, August 3, 2010

Adapted from Joel Achenbach's blog.

I've been thinking a lot about the Anthropocene. The Anthropocene is the name given by imaginative geologists to a new geological epoch shaped by human beings. It's not yet officially recognized as a scientific term. And the concept is not as flattering as it may sound at first blush. Ideally, we wouldn't have so drastic an impact on the world that it shows up stratigraphically.

You can see in the rocks of the Earth the pivotal biological moments. For example, the Permian-Triassic boundary can be found in sediments that are 251 million years old, and it marks the sudden disappearance in the fossil record of 95 percent of the planet's species. (The event is known as the Great Dying.)

We're officially living in the Holocene epoch, which began 11,600 years ago with a sudden warming event and the retreat of the glaciers. The Holocene has been an epoch of climate stability. It's been pleasant around here. We like the Holocene.

Except it may be over.

One obvious change is atmospheric, with the spike in carbon dioxide and resulting global warming. There's also the sudden mixing of species and their relocation around the planet thanks to human transportation. Invasive species and habitat destruction have led to a loss in biodiversity. All this has happened extremely quickly on the geological time scale.

Last week I attended the Aspen Environment Forum, which National Geographic's Dennis Dimick opened with a slide show he titled "The Man-Made World." It was visually arresting tour of what might be described as the transition from the Holocene to the Anthropocene. Dimick's premise is that for most of human existence we survived on contemporary sunshine in some form or another. Then we discovered coal, the genie in the Earth. Now we live off ancient sunshine (coal, oil, gas), which has made possible the extraordinary expansion of our population. But all trend lines show that this isn't sustainable. We have to return to a life based on contemporary sunshine.

There are scientists actively trying to persuade their peers that the Anthropocene is a stratigraphic fact, as real as the Permian-Triassic boundary. In sediments from 1945 and later we see the radioactive elements left over from atmospheric tests of atomic bombs. Or perhaps the Anthropocene started around 1800, when the Industrial Revolution took off.

Life in the Anthropocene has many nice qualities. Air conditioning comes to mind. But if it's not sustainable, then it's just another way in which we borrow from the future. We take what isn't ours. We squander resources.

We live like there's no tomorrow.

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