#1236 What is the Anthropocene?

What is the Anthropocene? The Anthropocene is the geologic age that we are in at the moment, although it is not agreed upon by experts.

Geologic periods are a way of dividing the Earth up into chunks that cover different stages in the life of the Earth. It is a little like breaking a human up into baby, toddler, teenager, etc. It gets a little confusing because they are broken up into eons, eras, periods, epochs, and ages. Eons are the largest and there are four of them. An eon is several hundred million years long and the longest is 2 billion. We are in the Phanerozoic eon at the moment. It started 538.8 million years ago and started with the appearance of the first animal fossils. The eons are then divided up into eras. Eras are tens of millions to hundreds of millions of years long. There are ten eras so far and we are living in the Cenozoic era. It started 66 million years ago and began with the extinction of the dinosaurs. Then there are periods. A period is from millions to tens of millions of years long. There are 22 periods so far and we are in the Quaternary period. It began 2.58 million years ago with the cooling of the planet and the expansion of ice sheets and glaciers. Humans appeared during this period. Then we have epochs and there are 37 of them. An epoch is hundreds of thousands to millions of years long. We are in the Holocene right now, which began 11,700 years ago at the end of the last glacial period. And the smallest unit is ages. Ages are thousands of year to hundreds of thousands of years long. There are 96 ages and we are in the Meghalayan right now. It began 4,200 years ago with a 200 year drought that had a huge impact on the humans in the middle east area. So, to be exact, right now in 2025, we are in the Meghalayan Age of the Holocene Epoch of the Quaternary Period of the Cenozoic Era of the Phanerozoic Ear, and it’s a Sunday.

We are looking at the Anthropocene, which is a theorized epoch. Officially, we are in the Holocene, but a lot of people think we should be in a new epoch that they call the Anthropocene. “Anthropo” comes from the Greek for human and “cene” means new. The argument is that humans have impacted the planet so severely, that we are into a new “human created” epoch that deserves its own classification. Interestingly, there is a group of experts that are in charge of naming or renaming all of the geologic ages and they voted against creating an Anthropocene. This group is called the Subcommission on Quaternary Stratigraphy (SQS) and they are a subgroup of the International Commission on Stratigraphy (ICS), which is a subgroup of the International Union of Geological Sciences (IUGS). Naming geologic time periods is a far more serious subject than I ever thought and they require a lot of evidence. This is the main reason why the Anthropocene has been voted down.

The suggestion that this time of the Earth’s history should be renamed comes about from the impact we are having on the planet. Homo sapiens have been here for roughly 200,000 years and for the largest part of our history, we didn’t have a huge impact. No more than any other animal. It was only as we developed our intelligence, our ability to talk, and our ability to make tools, that we started to have more impact. We began to make bigger changes when we invented agriculture 12,000 years ago, and began to make villages, towns, and cities. From 6,000 years ago we made bigger changes, but nothing that changed the whole planet. Those changes began with the Industrial Revolution, but even then, the changes weren’t enormous. Our incredible impact on this planet began roughly 60 years ago. This has been called the Great Acceleration. Everything has taken off. Al Gore talked about a hockey stick in his movie about climate change, but that hockey stick is not only for the climate. Everything goes up like that. The population. The number of cars. The amount of plastic produced. The amount of fossil fuel burned. The amount of carbon dioxide released. The number of cows farmed. The amount of habitat destroyed. The amount of ice melting. Everything goes up in the same way. That is not surprising because it all compounds and with over 8 billion people on the planet, it makes sense. And the geologists and scientists looked at this and thought we should have a new epoch named for it.

The trouble with defining a geological time period is that you need to have a start, and it is very difficult to define a start for the Anthropocene. Experts know roughly when it started, but there is no geological proof. There is not a new type of rock being laid down, or a new type of fossil being buried. Nothing. Some people think the Anthropocene started when we began to farm, or perhaps with the beginning of the Industrial Revolution, but there is no geological proof for that. Then a geologist had an idea. The Cenozoic era began with the extinction of the dinosaurs and the geological evidence for that turned out to be a layer of iridium all over the world at the same depth. The asteroid that caused the extinction of the dinosaurs contained a lot of iridium, which is not a very common element on Earth and pretty much only comes from space. That thin layer proved the end of one era and the start of the next. This scientist thought about that and wondered if we might not have something similar today. It took a lot of research, but it turned out to be radiation. During World War 2 and for about ten years after, several countries became nuclear powers and tested their nuclear weapons. This put a layer of irradiated material across the world that was buried at a constant depth. This would put the start of the Anthropocene in 1950. The idea was voted down by the SQS because they didn’t think there was enough evidence. I think that because of the way we are using the planet, there will be enough evidence soon. And this is what I learned today.

Try these next:

Sources

https://www.nhm.ac.uk/discover/what-is-the-anthropocene.html

https://education.nationalgeographic.org/resource/anthropocene

https://en.wikipedia.org/wiki/Geologic_time_scale

https://en.wikipedia.org/wiki/Holocene

https://en.wikipedia.org/wiki/International_Commission_on_Stratigraphy

https://en.wikipedia.org/wiki/Meghalayan

https://en.wikipedia.org/wiki/Phanerozoic

https://en.wikipedia.org/wiki/Cenozoic

https://www.nps.gov/articles/000/quaternary-period.htm

Image By Jarred C Lloyd – Own work, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=147428651

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