According to an international report, we have entered a new geological age and should recognize that fact.

A number of geologists have been appointed to a panel tasked with evaluating whether or not we should add an Anthropocene (Age of Humans) to the history of the Earth. The group released their preliminary recommendations on Monday, and they say that the Anthropocene time segment should be recognized. The release was published by the Anthropocene Work Group (AWG).

Human Footprint, Earth
Photo by Kevin M. Gill

On the hunt for a “golden spike”

The group is now working to identify a marker in the environment that can be used to show the beginning of this phase. The AWG report was presented to the 35th International Geological Congress in South Africa by secretary Colin Waters from the British Geological Survey.

“This is an update on where we are in our discussions,” he told BBC News. “We’ve got to a point where we’ve listed what we think the Anthropocene means to us as a working group. The majority of us think it is real; that there is clearly something happening; that there are clearly signals in the environment that are recognizable and make the Anthropocene a distinct unit; and the majority of us think it would be justified to formally recognize it.”

However the process is not yet finalized. “That doesn’t mean it will be formalised, but we’re going to go through the procedure of putting in a submission,” said Waters.

The challenge now is to look for a so-called “golden spike,” which is defined as a marker that will be used to pinpoint the start of the Anthropocene Epoch in years to come. Waters says that it would be an epoch, meaning that the current Holocene epoch is now over.

Anthropocene Epoch started in the 1950s

The working group has 35 members, 10 of whom believe that the “golden spike” could be plutonium fallout from nuclear bomb testing during the 1950s. This could be found in marine or lake sediments, layers of ice or perhaps speleothems like stalagmites and stalactites.

Other members of the panel believe that there may be better candidates for the “golden spike.” These include remnant plastics or a carbon signature that could provide evidence of the rapid increase in emissions of carbon dioxide.

Whichever marker is selected, the majority of the group believe that the 1950s is the right time. This period is known as the “great acceleration” and marks the time when humans started to impact the Earth much more intensely and on a global scale.

A decision on the golden spike is not expected to be made in the next two or three years. This is when the team will release their final assessment report, which will then be subject to scrutiny from the geological community around the world.

AWG appeals for help from global scientific community

If the Anthropocene Epoch is to be included in the “official” version of the history of our planet, it needs to be recognized by the International Commission on Stratigraphy (ICS) and receive ratification from the executive committee of the International Union of Geological Sciences (IUGS).

According to Waters the AWG is now looking for assistance from researchers who have samples of ocean sediment, speleothems, coral specimens and more. All of these pieces of evidence could be relevant to the golden spike.

“There may be research groups out there who have bore holes drilled through glacial ice, for example, which go through successions that could be used to define the Anthropocene,” said Waters. “If they were to make those available so that we could do analyses of all the different signals, it would help us understand better whether this concept of the mid-20th Century being the boundary is the best one.”

This would potentially save the AWG from having to drill new holes, which are expensive and time consuming.