Lake findings point to start of Anthropocene age
Sediment deposited at Crawford Lake, a small but deep body of water in Canada's Ontario province, provides unmistakable evidence that Earth entered a new human-driven geological chapter – the Anthropocene epoch – some seven decades ago, a team of scientists said on Tuesday. The members of the Anthropocene Working Group (AWG) plan to submit the evidence to the international scientific body responsible for naming geological chapters in Earth's history. The scientists conducted research at a dozen sites worldwide and cited Crawford Lake, near Toronto, as the location that provided particularly persuasive geological markers that the Anthropocene epoch – essentially the age of humans – has arrived. Plutonium from nuclear weapons testing in the 1950s provided "a very clear marker" for the transition to the Anthropocene and was accompanied by a surge in fossil fuel and fertiliser consumption, profound changes in land use and a decline in biodiversity caused by farming, said AWG chair Colin Waters, a professor at the University of Leicester in Britain. Presence of plutonium and other evidence was found in core samples of the Crawford Lake sediments. "At present, we've had 70 years of the Anthropocene," Waters said. "That has been long enough, because of the rapidity of the change and the preciseness of it, to recognise that we've moved into this new Earth state, and that it should be defined by a new geological epoch." The Anthropocene epoch is proposed as a chapter in Earth's history reflecting the transformation of the planet's climate and ecology as a result of human activity. But there has been disagreement within the scientific community about when this proposed epoch began and the evidence to demonstrate it. (Reuters)