Why geologists can’t agree on when the Anthropocene Epoch began

On a cosmological timescale, humanity’s existence is a mere blip. Yet, in our short lifetime, we have done outsized damage to Earth, so much so that some believe we need to invent a new geological epoch, the Anthropocene, to recognise the global change our species has caused. Technically speaking, we aren’t yet in the Anthropocene – but that is largely because experts can’t agree about when it started.

Ask most geologists and they will say we are still in the Holocene, a geological epoch that began about 11,700 years ago and is characterised by a period of planetary stability when human civilisation flourished. But therein lies the rub: our influence on Earth systems means these characteristics no longer apply, and a growing number of scientists believe a new epoch must be recognised. Enter the Anthropocene.

There is debate about who coined the term, but it was popularised in 2000 by atmospheric chemist and Nobel laureate Paul Crutzen and biologist Eugene Stoermer. They argued that the Anthropocene began in the “latter part of the eighteenth century”, around the time that global greenhouse gas emissions began to rise as the industrial revolution gathered steam. However, the Anthropocene Working Group (AWG) begged to differ. Established in 2009 and tasked with coming up with a formal definition of the epoch, its members said that the effects of human activity at that time were too scattered to provide a picture of global change. Instead, the date they came up with was 1952.

“The mid-20th century worked much better than any of the other candidates,” says …