Does this mean that humans haven't actually changed the planet? Not at all and while we may not officially be in a geological Anthropocene, the term will likely persist in reference to human environmental interference in years to come. As such, the wake of this vote is perhaps the best moment to consider a more essential question: what will we do next? Can we take the official rejection on an Anthropocene epoch as an implicit vote of confidence in our ability to return the planet to Holocene-like conditions? Is climate change reversible? As a limnologist, I can share insights from long-term research on lakes. And as one Canadian lake, Crawford Lake, had been selected as the candidate "golden spike" of the Anthropocene epoch, what lakes tell us of human impacts, and recoveries from those impacts, may be worth considering. There are elements of our future which cannot be undone. Although we can reduce future extinction rates, there is no coming back for the countless species that have disappeared due to human actions. Likewise, a global human-caused redistribution of species is a permanent symptom of (and evidence for) the Anthropocene. On the other hand, some measures of the Anthropocene seem inherently more ephemeral. The residues of widespread nuclear weapons testing through the 1950s into the 1960s have generally been seen as a particularly strong indicator of the Anthropocene. Scientists find evidence of this in lakes around the world in the form of trace amounts of Plutonium and Cesium in the sediments deposited during this period. A rapid drop in atmospheric bomb testing in 1963—upon the signing of the Nuclear Test Ban Treaty—has created a unique "bomb pulse" which represents a global, unequivocally human, fingerprint. The bomb pulse was considered evidence for a 1950 Anthropocene epoch start date and was likely the most critical factor in defining the Anthropocene. However, which global human signal is more... |