Sciency Words: Holocene (An A to Z Challenge Post)

April 10, 2017

Today’s post is a special A to Z Challenge edition of Sciency Words, an ongoing series here on Planet Pailly where we take a look at some interesting science or science related term so we can all expand our scientific vocabularies together. In today’s post, H is for:


Real dinosaur fans can tell you that dinosaurs lived in the Mesozoic Era, a geological era that is subdivided into the Triassic, Jurassic, and Cretaceous Periods.

Real fans of humans can tell you that humans live in the Cenozoic Era, in a subdivision called the Quaternary Period, in a further subdivision known as the Holocene Epoch—a name which can be translated from Greek to mean “entirely recently.” Again, scientists, you can be more creative than that.

This “entirely recent” epoch began approximately 11,700 years ago, a time which corresponds loosely to the end of the most recent ice age and also corresponds loosely to what archeologists call the mid to late Stone Age.

Major developments during the Holocene include melting glaciers, the extinction of animals like the woolly mammoth and saber-toothed tiger, and of course the rise and spread of human civilization.

The Holocene ends with… well, obviously we don’t know how it ends. Or maybe we do.

There’s an ongoing debate among geologists about whether or not the Holocene has ended already. Some say a new geological epoch—called the Anthropocene—has begun. Anthropocene is derived from the Greek word for human, and it would be characterized by the effects human activities are having on the geology of this planet.

The International Commission on Stratigraphy is in charge of naming geological time periods and defining their start and end points, and the I.C.S. has a working group studying the Holocene vs. Anthropocene issue.

If the Anthropocene is accepted as an official geological epoch by the I.C.S., then the Holocene may have ended about two hundred years ago with the beginning of the Industrial Revolution. There’s an alternative proposal that would have the Holocene end in the mid-20th Century with the dawn of the nuclear age, because changing levels of radioisotopes in rock strata would make the boundary between the two epochs easier to identify. And there’s a proposal to make the Anthropocene a subdivision within the Holocene, rather than making it its own separate epoch.

Whatever the I.C.S. decides to do, their decision will probably be controversial. But it won’t be the first time an international organization like this stirred up controversy over how to define scientific terms. More on that tomorrow.