The Anthropocene – a new epoch?

You’ve probably heard about humans altering the planet. But to what extent? Enough to justify a new geological epoch? This is a hotly debated topic within the scientific community, so read on if you’d like to form an opinion.

Geological epoch

A geological epoch is a segment of time in our planet’s geologic time scale, where its 4.6 billion years are divided hierarchically into eons, eras, periods, epochs and ages. These are designated by the International Commission of Stratigraphy.

Stratigraphy is the study of the relationship between Earth’s rock layers (strata) and the fossils found within them. By studying the fossils it’s possible to determine which organisms belonged to which epoch, and thus what makes each epoch unique and distinct.

The current official geological epoch is the Holocene, which began after the last major ice age some 11 700 years ago. The Holocene is the shortest epoch in the geological time scale and the surface bodies of sediment, such as soils and deltas, that we live on today were formed during the Holocene.

The Anthropocene

This brings us to the Anthropocene, a new (and as of yet unofficial) epoch. The word is derived from Greek, anthropo meaning “man” and cene meaning “new”. It was formulated and popularised by the chemist Paul Crutzen and biologist Eugene Stormer in 2000.

The Anthropocene is proposed to encapsulate the most recent time in our planet’s history, in which humans are the main agents of change, altering Earth’s climate and ecosystems permanently. Some examples include global warming, habitat loss and the extinction of species.

There has been much debate regarding when the Anthropocene began. Some claim that it began with the Industrial Revolution during the 18th and early 19th centuries, while others think it began in 1945, when humans began testing and dropping atomic bombs that caused radioactive pollution on a global scale.

To collect evidence and establish whether the Anthropocene should become an official geological epoch, the Anthropocene Working Group (AWG) was established in 2009. In 2016 the AWG recommended that the beginning of the Anthropocene should be placed during the mid-20th century, to coincide with the Great Acceleration (a period of intense population growth, urbanisation and industrialisation). The AWG further recommends the early 1950s as a starting point based on the thermonuclear bomb tests that took place during this time, spreading radioactive pollution globally.

Radioactive pollution could be traced in ice layers and sediments, providing good evidence of the Anthropocene beginning in the mid-1900s. Other potential evidence includes plastic pollution, soot particles from coal combustion and concrete particles. There’s also an argument for fossils from domestic chickens as a defining marker of the Anthropocene. Since the mid-1900s it’s the most common bird on Earth, and it’s larger with a different bone structure than pre-war chickens, which sets it aside from its ancestors.

Controversy

Nowadays there’s no doubt that humans have significantly altered the face of the planet. So, what’s the hang-up? To become an official epoch, the Anthropocene must be approved by the International Commission of Stratigraphy and the executive committee of the International Union of Geological Sciences. And for that to occur, there are a few requirements that need to be met.

First, there needs to be evidence that humans have altered the planet to the point that it shows up in the rock strata. Second, the term (Anthropocene) needs to be useful for the scientific community. Both requirements have, according to the AWG, been met.

However, unlike the fact that climate change is caused by human activities, there’s no scientific consensus regarding whether the Anthropocene should be an official geological epoch. One of the main critiques of the Anthropocene is that it’s an oversimplification that lumps all of humanity together as responsible for altering the planet. Instead, some have proposed calling it the ‘Capitalocene’, focusing on the profit-driven, developed countries and industries as responsible rather than the everyday person. As we know, not everyone contributes to climate change to the same extent, so the critique has some merit.  

What do you think? Is the Anthropocene a useful concept or not? Have humans altered the planet enough to justify a new geological epoch? It’s certainly a conversation starter. And if your thirst for Anthropocene-knowledge isn’t sated yet, we can recommend watching the Canadian documentary Anthropocene: The Human Epoch from 2018.

Sources:
Anthropocene | National Geographic Society
Entering the age of human impact | Lampoon Magazine

The Anthropocene: a new epoch of geological time? | Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
The Anthropocene Project | Home
What is the Anthropocene? And why does it matter? | World Economic Forum (weforum.org)
What is the Anthropocene? | National Trust
Working Group on the ‘Anthropocene’ | Subcommission on Quaternary Stratigraphy

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