A new epoch for mankind began about 1950. It is defined by radioactive fallout from nuclear bomb tests, plastic pollution, soot from power stations, high levels of nitrogen and phosphate in soils derived from artificial fertilizers, concrete, and the global proliferation of the domestic chicken (yes).

Ocean plastic. Photo: Dimitar Dilkoff/AFP/Getty Images

The  epoch we are leaving, the Holocene, lasted for 12,000 years  since the last ice age, during which a period of stable climate allowed human civilization to develop. About 1950, homo sapiens’ finely wrought advances began to spin wildly out of control. Carbon dioxide emissions, sea level rise, the global mass extinction of species, deforestation and mass development have thrown a wrench in the works of the planet’s machinery, setting earth on a permanently different trajectory.

Experts speaking at the International Geological Congress in Cape Town, South Africa recently likened it to a largish spaceship drifting out of control without a crew at the helm.

→For the full story, including the lowdown on the chicken, see the Guardian.