To anthropocene or not to anthropocene - that is the question.

Just when are we? Officially we are in the geological epoch known as the Holocene – unofficially however, no one seems to think that is actually the case.

Many now consider the Earth to have transitioned into the Anthropocene – an epoch entirely defined by our impact on the world. It started as an off-the-cuff remark by an atmospheric chemist and has mothballed into what must be as close to a revolution as geologists come. 16 years ago Nobel Laureate Paul J. Crutzen felt obliged to interrupt a discussion on geological timescales. The speaker had mentioned the Holocene – which cut absolutely no mustard with Crutzen. He thought it was outdated and proposed an entirely new epoch – the Anthropocene. Many geologists now agree that in terms of human influence on the globe, too much has happened in too short a timescale to pass unmarked on the geological record. As such the idea of the Anthropocene is in the ascendency.

But does all this matter – isn’t this just a question of abstract definitions? Well I’d say it matters a great deal. We are talking about the first time a single species has been responsible for an impact on the world so profound that it has actually changed its geology. We have singlehandedly altered the planet to such an extent it is becoming impossible to keep this off the books, as it were. There will be no loopholes for us – it will, almost certainly, be reflected in the official classification of the Earth’s geological history. This, it seems to me, is the most sobering thing about our existence on this planet. And to be sobered is, we can only hope, to take action. Far from abstract, that is as real as it gets.

We have singlehandedly altered the planet to such an extent it is becoming impossible to keep this off the books, as it were.

And, of course it’s not just rocks we are talking about here – our rather nasty fossil fuel habit has helped stuff carbon into the atmosphere at an incredible rate. So much so in fact that recent work published in Nature Geoscience suggests it may be unprecedented, at least since the age of the dinosaurs. The study attempts to figure out how much atmospheric CO? was responsible for the Palaeocene-Eocene Thermal Maximum (PETM) – a dramatic warming event 56 million years ago. They find the amount of CO? going into the air at its onset was four billion tonnes a year at most. Our current emissions are approaching ten times that.

And that is important – the PETM had been regarded as a useful correlate for what is happening on Earth now. It seems, then, that we have broken our own analogy. As a result we can no longer reliably learn anything about our current situation from the PETM and find ourselves in a ‘no-analogue state’. And its terms like this that add immense weight to the idea of the Anthropocene wouldn’t you say?

Perhaps not – Dr Colin Waters of the secretary of the Anthropocene Working Group lays out the case for this new epoch, and he is on the search for consensus here, so now is your chance to have your say.

Phil Prime Managing Editor Laboratory News