There is a movement afoot to change the Earth's timeline. In 2000 Paul Crutzen, an eminent atmospheric chemist, realised he no longer believed he was living in the 10,000-year-old Holocene epoch, a peculiarly stable and clement part of the Quaternary period, a time distinguished by regular shifts into and out of ice ages. Dr Crutzen decided he was living in some other age, one shaped primarily by people.

From their trawlers scraping the floors of the seas to their dams impounding sediment by the gigatonne, from their stripping of forests to their irrigation of farms, from their mile-deep mines to their melting of glaciers, humans were bringing about an age of planetary change. With a colleague, Eugene Stoermer, Dr Crutzen suggested this age be called the Anthropocene—“the recent age of man”. Here is an updated version of the timeline, taking account of the new era in which we are living.

Read the full briefing: A man-made world