Did the Anthropocene epoch begin in say 1950, or does one select a much earlier date, e.g., 2000 BC?
It is a highly debated question nowadays in the scientific community. If you think in terms of geological eras then the answer does not matter so much, as Earth eon datation is more likely to occur in hundreds of thousands or even millions of years.
That being say, the most convincing argument to me is to consider the period when humans started to actively intervene in the carbon cycle. Carbon transformation is a major geological activity of the different ecospheres, so that part of the argument makes sense.
About the exact date, I have heard many researchers talking about the end of the 19th century. At that time, manufacturing processes started to burn coal and fossil energies at an industrial scale. Some goes as far as taking 1784, the year when the steam machine was patented, as the marker (French researchers Bonneuil and Fressoz). I found it a bit exaggerated, and thought it expressed more their agenda that a deep scientific reflection.
The broader question - when did humans started to influence the course of this planet - does not have so far a satisfying answer. In my opinion, it is a good thing and we should keep it that way for now. It offers us a great opportunity to reconsider human history and condition under a new light, and asking ourselves how we have become part of this world.
This text was originally published in quora.