‘Loneliest tree’ records human epoch

Jonathan Amos Science correspondent @BBCAmos on Twitter

Image copyright PAVLA FENWICK Image caption The tree was planted around 1905 and puts on growth of about 1cm per year

It’s been dubbed “the loneliest tree on the planet” because of its remote location, but the Sitka spruce might represent something quite profound about the age in which we live.

The tree, sited on Campbell Island in the Southern Ocean, records in its wood a clear radioactive trace from the A-bomb tests of the 1950s and 60s.

As such, it could be the “golden spike” scientists are seeking to define the start of the Anthropocene Epoch – a new time segment in our geological history of Earth.