Friday, December 19, 2008

The Anthropocene?

Humans are inducing such rapid biological change to the planet that a scientific consensus is forming that we have entered a new geological epoch, the Anthropocene. The term was originally coined in 2000 by the atmospheric chemist Paul Crutzen, to denote that the impact of industrial-era humans on the planet were creating such an impact (notably by spurring climate change, but also more generally inducing a huge die-off in species) that our own era deserved a different moniker than the the standard Holocene--that is, the post-ice age era that began some 10 millennia ago. Geologists are now joining the bandwagon, arguing that human effects on the planet are creating a distinct stratigraphic signature, based on the about of exotic chemicals, radioactive elements, and above all carbon that we are spewing into the environment.

Obviously, I'm not an expert on such debates, but as a sometime historian, I know a thing or two about disputing periodization. My own view is that "in the long run" (that is, from the point of view some putative scientific observer millions of years from now), it would not make sense to demarcate the Anthropocene from the Holocene. In fact, seen in geological terms, the heat-up of the planet that happened 14,000 years ago and is now set to take another sharp uptick, should really be seen as one continuous process. Seen from the perspective of millions of years, the planet has been in a glacial period for several million years, with phases of warming and cooling, in which species were fairly stable. The last phase of cooling, however, happened to spit out a novel feedback element (modern humans, which evolved around 100-150K years ago) that happened to engage in behavior that diverted the usual cooling cycle, such that the planet now appears to be shifting to a definitively post-glacial period, more climatically akin to the way the world was some 55 million years ago.

However, seen in the millions-of-years perspective, the two distinct heat-ups -- the one 14K years ago and the one now -- look less like two distinct events, and more like one continuous event, rather than two distinct events, and should probably be interpreted as such. After all, the massive extinctions we are witnessing now are of the same order (and arguably, so far, less severe)  than the ones that took place 10K years ago, when much of the North American megafauna was killed off, radically changing the North American continental ecosystem.

Indeed, I'd argue that human-induced climate change is just another part of the wider ecosystemic feedback mechanism that humans are. Further, I'd argue that, qua feedback mechanism, humans are no different in our bio-geologic essentials than any other feedback mechanisms, such as the release of methane from melting tundra. I would argue that it is merely a conceit, a kind of species-narcissism, to think that just because we humans understand this feedback process that this makes our participation in that feedback mechanism somehow radically different from any other feedback loop. Neither scientific consciousness nor intellect generally are a geologic features.

1 comment:

Anonymous said...

"Humans are no different in our bio-geologic essentials than any other feedback mechanisms, such as the release of methane from melting tundra."
I disagree! Tundra does not drive SUV and probably had not had the opportunity to hear Al Gore's warning on warmimg. Anthropocene is relevant on a political point of view.