Currently, our earth is still situated in the Holocene epoch, which began 11,700 years ago. This followed the latest and most below-zero dissolution of the ice sheets and allowed human societal development through a period of stable climatic conditions. However, scientists and the international leading authority on geology, the International Union of Geological Sciences, have expressed differing views. Some have attempted to re-designate our current time as a distinct marker on the geologic calendar due to globally significant changes brought upon by human activity, such as nuclear technology, climate change and widespread pollution. This new period has been proposed to be named the Anthropocene.
Despite being a term frequently used in various disciplines, it will still be maintained and the notion has not been completely dismissed. The proposal to categorise our era as the Anthropocene, although refused on the grounds of insufficient conclusive evidence, was initially put forth by a subset of the International Union of Geological Sciences, the Anthropocene Working Group (AWG). It took them an extended 15 years to finally reach their proposal.
The geologic timeline partitions the history of our 4.6 billion-year-old planet into various sections, with the largest being eons, followed by eras, periods, epochs, and finally ages. Currently, according to this division, we reside in the Meghalayan age of the Holocene epoch, which belongs to the Quaternary period of the Cenozoic era within the Phanerozoic eon.
The AWG’s proposal suggests that the Anthropocene can be said to have commenced in 1952, when traces of plutonium from hydrogen bomb tests appeared in the Crawford Lake sediment, situated near Toronto, Canada. They believe this is the moment when the world saw a significant surge in human population, economic activities and greenhouse gas emissions, creating long-lasting impacts.
However, the idea of a distinct beginning is open to debate due to the gradual nature of these types of changes. When does gradual change morph into a qualitative difference? What criteria does an age need to fulfil to be upgraded to an epoch or a period? Should the beginning be traced back to the origins of agriculture or the industrial revolution? These questions highlight the predicament faced by geologists.