Scientists do not have a unified idea over the date marking the dawn of the human-dominated geological epoch called the Anthropocene. Researchers of a new study, however, suggest that the period started around the year 1610, which was characterized by unusual drop of carbon dioxide in the atmosphere and the irreversible exchange of species to and from the New and Old Worlds and vice versa.
An epoch can only be called as such once it meets two main criteria including documentations of long-lasting changes to the planet and scientists being able to identify and date a change in global environment that has been captured in rocks, sediments from the ocean floor and other natural materials, with such markers, such as the chemical signature associated with the meteorite strike responsible for the annihilation of the dinosaurs, known as a golden spike.
In a new study published in the journal Nature on March 12, Simon Lewis and Mark Maslin, from the University of College London, proposed that the Anthropocene started in 1610.
"Placing the Anthropocene at this time highlights the idea that colonialism, global trade and the desire for wealth and profits began driving Earth towards a new state," Lewis said. "We are a geological force of nature, but that power is unlike any other force of nature in that it is reflexive, and can be used, withdrawn or modified."
The researchers said that after the arrival of the Europeans in the Americas in 1492, global trade as well as movement of species across continents have occurred and these have led to the global re-ordering of life on Earth, a cross-ocean exchange of species that was unprecedented in the history of the Earth.
"Maize from Central America was grown in southern Europe and Africa and China," Lewis said. "Potatoes from South America were grown in the UK, and all the way through Europe to China. Species went the other way: wheat came to North America and sugar came to South America - a real mixing of species around the world."
Lewis and Maslin also found a golden spike, a pronounced drop in atmospheric carbon dioxide that occurred by 1610 as a result of the arrival of the Europeans in the Americas. The growth of trees and vegetation by this time removed sufficient amount of carbon from the atmosphere that led to a drop in carbon dioxide. The researchers dubbed this 1610 dip in the carbon dioxide as the "Orbis spike."
Photo: Perry McKenna | Flickr
