Human activity has left an indelible mark on our planet, to the extent that some scientists argue we’ve entered a new geological era known as the Anthropocene. This epoch represents a period in which human actions have significantly reshaped the Earth’s fabric. But what exactly does this mean, and how did scientists arrive at this conclusion?
What is an epoch?
Before delving into the Anthropocene, let’s understand what an epoch is and its significance. Geologists, experts in studying rocks and minerals, unravel the Earth’s billions of years of history by dividing it into distinct sections called epochs. These epochs serve as markers for major shifts in the planet’s atmosphere, biology, and geology, marking significant events like mass extinctions, meteor impacts, and alterations in the Earth’s chemical composition.
Currently, some in the scientific community believe we’re still in the Holocene epoch, which began over 10,000 years ago after the last major ice age. However, many others contend that the Anthropocene epoch is already underway. What sets the Anthropocene apart is that it reflects the idea that human beings have caused such a profound physical impact on Earth that, unlike previous epochs lasting millions of years, we’ve triggered a new epoch within a relatively short span of time.
To ascertain the start of the Anthropocene, scientists have turned to innovative techniques and intriguing discoveries. One such discovery took place in Crawford Lake, located west of Toronto, Canada. Why lakes, you might ask?
Lakes are significant because they collect atmospheric particles which settles on the lake’s floor forming sediment. This acts as a record of environmental changes over time. Recently, scientists froze a section of sediment from Crawford Lake, resembling stacked layers like a tube of Pringles, with each layer representing a distinct period in history. By studying these layers, researchers were able to rewind the clock and identify critical environmental markers that shed light on past atmospheric conditions.
The ‘golden spike’
The findings in this chunk of frozen mud were nothing short of revelatory. Among the sediment layers, scientists documented a “golden spike,” a sudden and drastic shift in Earth’s conditions. The layers contained evidence of human-made materials such as microplastics, particles from burning fossil fuels, and even plutonium from bomb testing during the 1950s. This compelling evidence lends support to the argument that human activities have caused irreversible changes to the planet’s ecosystems, strengthening the case for the Anthropocene epoch.
What happens next?
The group of scientists responsible for this discovery aims to present their evidence to the International Union of Geological Sciences. As the authority responsible for naming geological chapters in Earth’s history, this body will ultimately decide whether the Anthropocene epoch deserves official recognition.