Coming after nearly 15 years of deliberation, a ruling by geologists on Tuesday feels almost anticlimactic: Our species has not so radically altered our world as to have started a new chapter in its history, at least not yet, a scholarly panel decided.
But even if textbooks and research papers don’t feature the “Anthropocene” epoch anytime soon, earth scientists have no doubt that humans are changing the planet. In deciding whether or not to amend the geologic timeline to reflect this, they contemplated a variety of human-driven changes that will be marked in the rocks for a long time to come.
In the end, several scholars who voted on the Anthropocene question said humankind had left too many different kinds of imprints on nature, over too broad a stretch of time, to be captured neatly by a single starting point, which is what geological timekeeping requires.
Here are some of the planet-spanning changes they considered.
Nuclear fallout
A key part of the case that some scientists made for declaring the start of the Anthropocene epoch was the pulse of radioactive isotopes that hundreds of nuclear detonations scattered across the Earth in the mid-20th century. There’s zero doubt that humans are responsible for these particles, even if they end up in different places at slightly different times.
Some scholars have, however, voiced concern about whether using weapons of mass destruction to signpost humankind’s transformation of the planet would send the wrong kind of message about our time.
