An official welcome to the Anthropocene epoch - but who gets to decide it's here?

It's literally epoch-defining news. A group of experts tasked with considering the question of whether we have officially entered the Anthropocene - the geological age characterised by humans' influence on the planet - has delivered its answer: yes. The British-led Working Group on the Anthropocene (WGA) told a geology conference in Cape Town that, in its considered opinion, the Anthropocene epoch began in 1950 - the start of the era of nuclear bomb tests, disposable plastics and the human population boom. The Anthropocene has fast become an academic buzzword and has achieved a degree of public visibility in recent years. But the more the term is used, the more confusion reigns, at least for those not versed in the niceties of the underpinning science. Roughly translated, the Anthropocene means the "age of humans". Geologists examine layers of rock called "strata", which tell a story of changes to the functioning of Earth's surface and near-surface processes, be these oceanic, biological, terrestrial, riverine, atmospheric, tectonic or chemical. When geologists identify boundaries between layers that appear to be global, those boundaries become candidates for formal recognition by the International Commission on Stratigraphy (ICS). The commission produces the International Chronostratigraphic Chart, which delimits verified changes during the planet's 4.5 billion-year evolution. The chart features a hierarchy of terms like "system" and "stage"; generally, the suffix "cene" refers to a geologically brief stretch of time and sits at the bottom of the hierarchy. We have spent the past 11,500 years or so living in the so-called Holocene epoch, the interglacial period during which Homo sapiens has flourished. If the Holocene has now truly given way to the Anthropocene, it's because a single species - us - has significantly altered the character of the entire hydrosphere, cryosphere, biosphere, lithosphere and atmosphere.