The Anthropocene draws to a close

The term Anthropocene was coined by Nobel laureate Paul Crutzen a decade ago to describe the new ‘Era of Man’, a distinct geological epoch shaped almost entirely by our actions and impacts. “The Anthropocence has yet to be accepted as a geological time period, but if it is, it may turn out to be the shortest – and the last”, wrote Bob Holmes in the current edition of New Scientist in an intriguing article that rolls the clock forward to see how Earth would cope in the era after Man.

Mass extinctions are already well advanced, so much so that scientists have already designated the current era as the Sixth Extiction – since these measures cover close to a billion years, Extinction eras are rare indeed, the last being the event 65 million years ago that did for the dinosaurs and ultimately created the wiggle room for our ancient ancestors, the early mammals, to get a toe-hold.

In terms of dramatic warming, the era closest to our own is the Palaeocene-Eocene thermal maximum, 55 million years ago or so, when it’s known temperatures rose by in the region of 9C – over a period of several thousand years. There is simply nothing in the fossil record to compare with the possibility/probability of that level of global temperature rise occurring in a matter of decades, but that’s precisely where our current carbon-fuelled trajectory is taking us.

The good news, after a fashion, is that Earth is a resilient old rock and should dust itself off once this latest extinction event has played out. The less good news is that rebound takes a long, long time. “Recoveries from mass extinctions are geologically rapid, but from a human point of view grindingly long. We’re talking about millions of years”, said David Jablonski, palaeontologist at the University of Chicago.

As reported recently in this blog, the UK Met Office’s Hadley Centre has published its conclusions based on extensive computer modelling that we’re on track for a 4C global average heating by 2060, i.e. barely 50 years hence. To describe this outcome as disastrous is a grevious understatement, but as I attempt to explain in today’s newspaper column, the reaction to this unfolding fiasco has been, at best, muted.

Whether it’s self-pity over our recent fall from grace as the richest kids on the planet (a story currently being chronicled by David McWilliams in his 3-part RTE series, Addicted to Money) or just a continuation of the self-delusion that waltzed us into our financial imbroglio, nobody, but nobody here, at least not in our media, has even begun to comprehend just how deep the do do we’re sinking into really is.

For the uninitiated, 4C means hell on earth. A separate article in the current New Scientist runs the numbers based on the Hadley Centre findings. To summarise: no rainforests, no monsoon, dramatic sea level rises, hydrological chaos leading to starvation for hundreds of millions, running into billions. The Amazon up in smoke. Temperatures in the polar regions shooting up by 10-16C, leading not just to catastrophic melting, but also triggering the release of tens of billions of tons of methane currently trapped in the vast permafrost regions of northern Canada and Siberia.

When that lot hits our atmosphere – boom! “The glimmer of hope? It doesn’t have to be this way. If politicians at the UN climate change talks in December agree to cut emissions by 3 per cent every year, the world can (with a slice of luck as well) limit temperature rises to a “safe” 2C, the Met Office says”. The heat is on.