That new epoch began between October and December 1965 according to new research published today in Scientific Reports by members of the Australasian Antarctic Expedition 2013-2014, which was co-led by co-author Professor Christopher Fogwill from Keele University. The researchers were able to mark this profound change so precisely because of a “golden spike” found in the heartwood of a strange and singular tree, a Sitka Spruce found on Campbell Island, a World Heritage site in the middle of the Southern Ocean The spruce is locally referred to as ‘the loneliest tree in the world’ with the next closest tree over 200km away on the Auckland Islands. READ MORE: It's Not Just Global Warming, Folks, as Humanity Enters New Anthropocene Epoch

Scientists looking for the definitive point in time at which the human impact on the planet became truly global have focussed their attention on what has been dubbed the "loneliest tree on earth," the Sitka Spruce on Campbell Island some 200km south of New Zealand. Though scientists have shown that humans have been influencing the planet's ecosystems for thousands of years, many consider the sudden spike in radioactive carbon caused by the testing of nuclear weapons in 1950s and 1960s the mark of humanity's newly dominant role as chief driver of climatic change. Professor Fogwill, Head of the School of Geography, Geology and the Environment at Keele University, said:

Various researchers from around the world have been talking about declaring a new geological epoch called the Anthropocene, indicating the point where human influence on the planet fundamentally changed the natural world. 'We were incredibly excited to find this signal in the Southern Hemisphere on a remote island, because for the first time it gave us a well-defined global signature for a new geological epoch that could be preserved in the geological record,' said lead author Professor Chris Turney from the University of New South Wales.
In a Scientific Reports publication, researchers propose 1965 as the start of the Anthropocene era. In that year, human nuclear weapons testing caused a noticeable spike in radiocarbon in the heartwood of the world's remotest tree, a Sitka spruce on Campbell Island, New Zealand. The general scientific community has already been using 1950 as the year "Before Present", when nuclear weapons began to significantly affect the reliability of radiocarbon dating of objects whose organic matter content formed after that epoch.