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. The International Commission of Stratigraphy designates these.
Stratigraphy studies 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 popularised chemist Paul Crutzen and biologist Eugene Stormer formulated The Anthropocene in 2000. They derived the word from Greek, anthropo meaning “man” and cene meaning “new.”
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 species extinction.
There has been much debate regarding when the Anthropocene began. Some claim that it started with the Industrial Revolution during the 18th and early 19th centuries. In contrast, others think it began in 1945 when humans began testing and dropping atomic bombs that caused radioactive pollution on a global scale.
The Anthropocene Working Group (AWG) was established in 2009 to collect evidence and verify if the Anthropocene should become an official geological epoch.
The AWG recommended placing the beginning of the Anthropocene during the mid-20th century to coincide with the Great Acceleration (a period of intense population growth, urbanization, and industrialization).
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 International Commission of Stratigraphy and the International Union of Geological Sciences executive committee must approve the Anthropocene. 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 where 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 human activities cause climate change, 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 profit-driven, developed countries and industries as responsible rather than everyday people. 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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