Scientists Say We're Not in the 'Age of Humans'

The Anthropocene or age of humans will for now remain an unofficial unit of geological time. A committee of scientists has voted down the idea of the Anthropocene epoch marked by humans' significant impact on the planet after some 15 years of debate. A panel of experts was convened in 2009 to determine whether recent changes to the planet warranted a new geological epoch. The panel determined the Anthropocene had begun around 1950 and offered up Ontario's Crawford Lake as evidence. The lake had preserved records of microplastics, ash from coal-fired power plants, and radioactive plutonium from atmospheric atomic bomb tests in its sediments, as panel member Naomi Oreskes explained at Scientific American.

To make the Anthropocene official, the proposal needed to gain 60% support from three separate committees under the International Union of Geological Sciences, but it didn't even get past the first. The Subcommission on Quaternary Stratigraphy rejected the Anthropocene with a 12-4 vote last month with two abstentions, the New York Times reports. Several members found the proposal's definition of the Anthropocene too limited. "Human impact goes much deeper into geological time [than 1950]," said committee member Mike Walker, an earth scientist and professor emeritus at the University of Wales Trinity Saint David, per the Times. "If we ignore that, we are ignoring the true impact, the real impact, that humans have on our planet."

Such a definition "narrows down the whole importance of the Anthropocene," added committee member Jan A. Piotrowski, a geologist at Denmark's Aarhus University, arguing that the onset of agriculture, the Industrial Revolution, or the colonizing of the Americas could arguably show how humans reshaped the planet. The decision to stick with the current Holocene epoch, which began with the most recent glacial retreat 11,700 years ago, doesn't mean experts refuse to believe plastics, industrial ash, greenhouse gases, and radionuclides are leaving their mark. Walker, Piotrowski, and others just refer to the Anthropocene as an "event," rather than an "epoch." Scientists in the future might decide the committee was wrong, Piotrowski acknowledges. After all, "our impact is here to stay," he tells the Times. (More Anthropocene stories.)