One highlight of a fine day at the Geological Society of America meeting in Minneapolis yesterday was a lunchtime panel discussion about Nobelist Paul Crutzen's proposal to add a new time unit, the Anthropocene, to the geologic time scale signifying the present time when humans are a major force in geologic cycles. I think it's fair to say that the five panelists and the audience of geologists were not enthusiastic about that particular idea, for reasons I laid out nine years ago when I first wrote about the proposal: it would break the traditional rules of stratigraphy, it would be hard to define, it would be hard to use in the field, and it wouldn't add a lot to the great conversation of science.
A few people took it seriously enough to propose how to mark and detect the beginning of the Anthropocene. Richard Nevle, of Stanford, said that because humans tend to burn things, starting with the forests and moving on to fossil fuels today, he would look at the geologic record of fire. A commenter in the audience suggested the atomic test at Bikini Atoll, which disrupted the global atmospheric isotope record.
The eminent Precambrian specialist Paul Hoffman played the deep-time card, suggesting that we try to look at the Anthropocene from the viewpoint of future geologists 10 million years from now. To them, he said, it would be "a deep-sea core record of a drastic rise in the oceanic lysocline" based on the atmospheric carbon dioxide pulse and its effect on ocean acidity. His opinion was that in the record, it would look comparable to the Paleocene-Eocene thermal maximum and would be just as mysterious to those future scientists. I think one point he was making was that we're too close to this event to speak about it the same way we talk about, say, the Miocene.
Stanley Finney, the current chair of the International Commission on Stratigraphy, is the guy in charge of the geologic time scale. He was polite but firm in pointing out the problems of formally naming the Anthropocene and its lack of utility to scientists. But he, like every single other speaker, was strongly in favor of using "Anthropocene" for something. Later in the discussion he said, almost out of the blue, "Maybe the geologic time scale stops now."
Dorothy Merritts of Franklin & Marshall College was first to say that the Anthropocene is a great teaching tool. The term has caught the public's attention, she said, and it addresses many changes, such as land use and habitats, besides atmospheric chemistry. Emlyn Koster of the Liberty Science Center echoed this, calling the concept a unique opportunity to reinforce the relevance of geology that can "give us a place at the table." He is publishing an eloquent commentary in Geoscientist on the topic and read from it in his remarks.
Everyone, to a person, said that the Anthropocene is a desirable concept. My own opinion mutated during the session. Now I think that all of us should take ownership of the term and work it into the language; there the people will endow it with its true meaning. And with any luck, the vague campaign to formalize the Anthropocene will solidify, like urban legends, into the public's firm conviction that "the geologists gave our present age a special name." That's when Paul Crutzen's idea, first published in 2000, will have made its mark.