A study published in the Nature journal suggests that the start of the controversial geological Anthropocene period – also known as the “Age of Man” has had its beginnings in the 1600’s, immediately after the colonization of the Americas.
The Anthropocene is proposed as a new chronological epoch that should define the period in which human activities start to significantly alter and impact the Earth in fundamental ways. The study’s researchers proposed the date – more exactly 1610 – by searching for what they deem as “golden spikes”, or patterns in human activity that had a global significance over our planet.
An example of a golden spike happened after the colonization of the Americas, which unprecedentedly resulted in species restricted until then to the continent – such as maize and potatoes – being cultivated all over the world, being spread by the grand trading empires of the time. The paper states that this caused significant change to the ecosystem which would have not have otherwise happened without human interference, possibly affecting the evolutionary course of Earth’s ecosystem.
Also, colonization of the Americas had settlers bring in new viruses and bacteria to which the native populations’ immune systems were not adapted, causing the death of almost 50 million people at the time. Most of them were individuals which practiced agriculture, whose cultivated lands were then taken over by wild vegetation, which in turn helped reduce the concentration of carbon dioxide (CO2) in the air.
The specific date proposed, 1610, marks the lowest concentration of CO2 found in ice-cores for that time. Another similarly proposed date was 1964, immediately after the banning of nuclear tests; this point saw the high concentration of radioactive emissions in the atmosphere bought by decades of intense nuclear activity drop significantly.
Geologically, Earth is still considered to be in the Holocene epoch that started about 12.000 years ago, which is in turn part of the bigger Quarternary. This classification is becoming more and more contested by the scientific community, as the human factor altering natural conditions become more and more obvious. The most disputed aspect is the exact date which saw the proposed Anthropocene start and the considerations of choosing it, with some researchers considering that spread of human activity throughout the Earth is enough to mark its beginning. Other researchers propose that industrial and chemical developments in recent periods were the ones which saw man fully change the course of Earth’s natural development.
Image Source: The Economist