Anthropocene is a proposed geologic chronological term for an epoch that begins when human activities have had a significant global impact on the Earth’s ecosystems.

The Anthropocene is a term describing a geological epoch that begins when humans began having a significant impact on Earth’s ecosystems. It may sound somewhat ironic but, according to the authors of a new paper, that era begins in 1610 with a marked drop in atmospheric carbon dioxide.

For a period of time to be marked as a geological epoch, two things are required. The first requirement is that lasting changes to the Earth need to be documented.

The second is that scientists must be able to point to a date that environmental change has been captured by natural material. This could include rocks, ocean sediment, ancient ice such as that found in glaciers or some other material.

Previous epochs were marked by things like sustained volcanic activity, the shifting of the continents and meteorite strike.

The study, published in the journal Nature, examines the environmental impact of human activity during the last 50,000 years, and looks for impacts that meet the two criteria for an epoch.

One possible start for the Anthropocene was 1964. That year saw a spike in radioactive fallout due to an increase in nuclear weapons testing. The fallout is found in many geological deposits. The researchers not that by the 1960s, the human impact on Earth’s ecosystems was pronounced and that nuclear war could dramatically alter the Earth over the long term. However, to date there has been no nuclear war and nuclear weapons have not substantially altered the Earth.

The researchers also considered the late 18th century, when the industrial revolution led to a substantial increase in atmospheric carbon dioxide. That increase will also have a substantial ecosystems. However, it is not clear how long that change will last because it depends, in part, on how long the increase in carbon dioxide is allowed to continue for. The researchers also could not find a ‘golden spike’ to mark the start of the Epoch because the increase in carbon dioxide was gradual.

The date the researchers settled on and believe should mark the start of the Anthropocene was 1610.

The first Europeans began to arrive in the Americas in 1492. What followed was what the scientists refer to as “a global re-ordering of life on Earth”.

The first fossilized marine sediment of Latin American maize appears in Europe in 1600 and after that date becomes common. The rapid exchange of species between continents, including deliberately imported plants and animals and stowaways that became invasive species was more pronounced than anything since the continents drifted apart.

The most notable change however, the one that can be easily identified in geological records, is 1610. That year marks a substantial drop in atmospheric carbon dioxide, which was captured in Antarctic ice-records.

The drop, according to the researchers, was a direct result of the arrival of Europeans in the Americas. More specifically it was due to a rapid increase in forestation caused by a rapid decrease in population.

Within a few decades of the 16th century, an estimated 50 million indigenous people died from smallpox. Farming in much of Latin America went from being a wide-spread practice to almost nonexistent. When this happened Forests and vegetation moved quickly to reclaim abandoned farmland, villages and other lands. The regrowth of forests was so substantial that it produced a sudden and dramatic drop in carbon dioxide.

This, according to the papers authors, is the ‘golden spike’ which marks the dawn of the Anthropocene.

“A more wide-spread recognition that human actions are driving far-reaching changes to the life-supporting infrastructure of Earth will have implications for our philosophical, social, economic and political views of our environment. But we should not despair, because the power that humans wield is unlike any other force of nature, it is reflexive and therefore can be used, withdrawn or modified. The first stage of solving our damaging relationship with our environment is recognising it,” said Lead author, Dr Simon Lewis, UCL Geography and University of Leeds, in a statement.

“Historically, the collision of the Old and New Worlds marks the beginning of the modern world. Many historians regard agricultural imports into Europe from the vast new lands of the Americas, alongside the availability of coal, as the two essential precursors of the Industrial Revolution, which in turn unleashed further waves of global environmental changes. Geologically, this boundary also marks Earth’s last globally synchronous cool moment before the onset of the long-term global warmth of the Anthropocene,” he added.

The ultimate decision on whether and when to mark the beginning of the Anthropocene will be made by the Anthropocene Working Group of the Subcommission of Quaternary Stratigraphy. A decision is expected in 2016.