The Anthropocene
I’m a sucker for nerdy facts or news, so when I saw a flurry of articles on the Anthropocene this last week it piqued me. Now, as far as I can tell there’s no actual new news.. Just the Economist shamelessly using the term to knoll (possibly rightfully) doom about the state of US politics and Donald Trump. But I ended up doing a little bit of reading.
This post isn’t actually a summary of the Anthropocene - I don’t have years to go get a degree on it. You can read this great description from the Natural History Museum to get the idea. For my purposes suffice to say it’s a distinctive period of time in which geology and ecosystems have changed.
What’s interesting for me is the context it sits in, which is something none of the news articles I read tried to explain.
For one, the Anthropocene is really just an epoch. That sounds really big but in the nomenclature turns out to be pretty small. You can look at the Wikipedia Geologic Time Scale page to see the following non-abbreviated table
| Geochronologic unit (time) | Time span |
|---|---|
| Eon | Several hundred million years to two billion years |
| Era | Tens to hundreds of millions of years |
| Period | Millions of years to tens of millions of years |
| Epoch | Hundreds of thousands of years to tens of millions of years |
| Subepoch | Thousands of years to millions of years |
| Age | Thousands of years to millions of years |
So if we take a comparison with things we’re probably more familiar with… like the Jurassic period: that’s a relatively short period of (only) ~56 million years. Which itself has 3 epochs and 11 ages. It’s the one we all remember as ending with a meteorite killing all the dinosaurs, even though that’s really only a theory.
Or say we take the Cambrian period which ended 284 million years before the Jurassic started. That lasted ~53 millions years and is well known for the Cambrian explosion - the time during which we went from small, simple unicelluar organisms dominating the world to complex multicelluar ones. By the end of that period there were actually plants on the barren rocky earth as well as the new existence of myriapods, arachnids, and hexapods popping up in fossilised records. Of course.. That period also ended in an extinction event. Us humans love to remember times of both great abundance and great decline.
These were events of enormous change and out of the periods that exist - only 22 periods in total dating back 2500 million years ago - those two are some of the smallest, perhaps delineated as their own period indeed due to the great upheavals that happened during them. Epochs are slightly less clear, they’re less well known and perhaps less dramatised.
There’s a summary of a few interested epochs on WorldAtlas that I enjoyed. The Paleocene rings a bell - the time when mammals popped up. As does the Pleistocene - the time of the last ice age as animated in films such as .. Ice Age (very appropriate name, if only it was the only one). The Pleistocene also being the time we humans spread across the continents. So, epochs are still very significant times but perhaps as I understand it, less upheaval of what can actually be alive or what the basics of life look like.
This kind of context for me does actually make the Anthropocene more of a big deal. We’re having our own extinction event right now and remodelling the planet in ways that are pretty significant. On a time scale though, here’s one bit of perspective for you below. The New York Times put together an animation of the tectonic shifts going back 1000 million (Ma) years ago and it’s pretty amazing. Weird to think our current world as we envisage it has only existed since around the time of the Pleistocene 2.6 millions years ago.
* Hopefully you can see them but I’ve added links throughout the post