Sometimes the world seems like one big adventure in speculative fiction. It’s 2011, obviously, but that’s not a very epic scale to be thinking on for those of a fantastical or science fictional bent. Adjust your brain to the scale of geological time, and we live in the Holocene Epoch of the Quaternary Period of the Cenozoic Era of the Phanerozoic Eon. The Holocene began something like 12,000 years, the blink of an eye in big picture terms; the Phanerozoic’s been running for over 500 million years.
What’s got me thinking about all this is that – as those who follow the news may well have heard – there’s a serious proposal on the table, for consideration by those scientists who worry about such stuff, to officially declare the Holocene Epoch over. To consign it to the past, and recognise that the world has entered a new geological Epoch: the Anthropocene. It’s a technical little tweak to the obscure nomenclature of time to which only a tiny fraction of humanity need pay any attention. But … but, it’s also an extraordinary thing to let your imagination explore for a while.
The justification for ushering in the Anthropocene Epoch is basically pretty simple. The idea is that we humans have exerted such an influence over the Earth’s natural processes on a planetary scale that future scientists, vast stretches of time from now, will be able to look at the rocks and detect clear, consistent signs that something vast and dramatic changed. That change was us. The fundamental processes at work on the only planet in the universe we currently know supports life have been so profoundly altered by the feverish activity of just one amongst the millions of species inhabiting that planet that a new Epoch is called for.
The change over from one Epoch to another has in the past been marked by such dramas as the beginning or end of global Ice Ages, and mass extinctions associated (perhaps) with global catastrophes like asteroids bumping into the Earth. Now we can possibly say that Homo sapiens itself in that category of radically world-altering events. Who would have guessed, watching a little group of hairy primates wandering around in Africa all that time ago, that they’d grow up to change the geology of the entire planet?
I find it awesome stuff, that makes me stop, just for a few minutes in the heady rush of day-to-day concerns, and think about bigger stuff (before I get back to packing podcast mp3s onto my player). What’s most striking to me is the diversity of broader effects that are associated with this potential Epochal shift, and how we little humans, with so little conscious effort, seem to have matched the efforts of raw Nature in convulsing the planetary systems.
The ebb and flow of Ice Ages is associated with big changes in global sea level, for instance; we’ve got sea level rises already modestly underway, with an unknown increase yet to come (I’m in the camp that suspects it’s a consequence of human activity, as you might guess). Quite a few Epochs (and the higher level Periods) end with mass extinction events; we’ve certainly got a spike in extinction underway, as a (mostly unintended, but I’m not sure that’s much of an excuse) consequence of human activity. Whatever the catastrophe that did for the dinosaurs at the end of the Late Cretaceous Epoch, it seems to have left its fingerprint all around the world, with a very thin layer of rocks abnormally high in Iridium. My favourite proposal for a precise marker for the start of the Anthropocene that future geologists will be able to rely upon is just such a very thin layer, one that we put there: atomic bomb testing began in 1945, and it’s left its trace all over the Earth in faintly radioactive deposits.
If 1945 is settled upon as the start of the Anthropocene, there’s a thought to conjure with. I imagined living through the start of a new millenium was a wee bit special. In hindsight, my parents, and others alive at the end of the Second World War, have rather got me beat: it looks like they lived through the start of a new planetary Epoch – a distinction they share, out of all the billions of humans who have ever existed, only with the microscopically small number of Homo sapiens alive when the Holocene began all those 12,000 years ago.
And go further, pursue this Big Time, Stapledonian thought a little further. That Phanerozoic Eon I mentioned at the start, the 500+ million year slab of time of which the Anthropocene will be just a fractional subset: it’s defined by the appearance and diversification on a vast scale of abundant, complex animal life. We live in it still, but for how much longer? We’re not about to see the disappearance of all animals larger than a worm any time soon, but any good student of science fiction already knows how the Phanerozoic will end. Indeed, I’ve got a suggested name for the Eon that will replace it, if the dreams of countless sf authors and transhumanists are realised: the Mechanozoic. Self-replicating artifical intelligences all over the place, uploaded human consciousnesses walking around in mechanical shells or living out their lives in digital wonderlands. The rise of the mind-machine hybrid, whatever form it takes, will surely be the cue for us to ditch the Phanerozoic and move boldly into a new Eon. (There’s another obvious candidate for the instigation of a new Eon, of course: the permanent spread of terrestrial biological life beyond Earth).
However the Phanerozoic ends, those alive at that moment (assuming something’s not gone really horribly wrong and there is actually something roughly human still around) will really have something to crow about, since the only living things to have previously experienced such a transition were little wriggly and blobby things that weren’t big on conversation. I’m guessing they never even noticed it happening.