When was the Dawn of the Anthropocene?
August 30, 2016
New conversation about exactly when the Anthropocene – a new geological age in which Man has been the primary driver of planetary conditions.
Current discussion is around the idea that a “golden spike”, or marker, will be the agreed upon event that future generations will fix as the new age’s beginning. Will that marker be radioactive isotopes from the nuclear age? or bits of indestructible plastic in sedimentary rock?
A growing group of scientists maintain that the real impacts of human civilization on climate go back even much further, to the beginning of agriculture, as Steve Vavrus outlines above.
Humanity’s impact on the Earth is now so profound that a new geological epoch – the Anthropocene – needs to be declared, according to an official expert group who presented the recommendation to the International Geological Congress in Cape Town on Monday.
The new epoch should begin about 1950, the experts said, and was likely to be defined by the radioactive elements dispersed across the planet by nuclear bomb tests, although an array of other signals, including plastic pollution, soot from power stations, concrete, and even the bones left by the global proliferation of the domestic chicken were now under consideration.
The current epoch, the Holocene, is the 12,000 years of stable climate since the last ice age during which all human civilisation developed. But the striking acceleration since the mid-20th century of carbon dioxide emissions and sea level rise, the global mass extinction of species, and the transformation of land by deforestation and development mark the end of that slice of geological time, the experts argue. The Earth is so profoundly changed that the Holocene must give way to the Anthropocene.
Below, John Cook and I interviewed Bill Ruddiman himself on the issue:
Prof Chris Rapley, a climate scientist at University College London and former director of the Science Museum in London said: “The Anthropocene marks a new period in which our collective activities dominate the planetary machinery.
“Since the planet is our life support system – we are essentially the crew of a largish spaceship – interference with its functioning at this level and on this scale is highly significant. If you or I were crew on a smaller spacecraft, it would be unthinkable to interfere with the systems that provide us with air, water, fodder and climate control. But the shift into the Anthropocene tells us that we are playing with fire, a potentially reckless mode of behaviour which we are likely to come to regret unless we get a grip on the situation.” Rapley is not part of the WGA.
Martin Rees, the astronomer royal and former president of the Royal Society, said that the dawn of the Anthropocene was a significant moment. “The darkest prognosis for the next millennium is that bio, cyber or environmental catastrophes could foreclose humanity’s immense potential, leaving a depleted biosphere,” he said.
The hunt is now on for a “golden spike”, as it is known – the marker that scientists can point to years hence – perhaps millions of years hence – and say, “There! That’s the start of the Anthropocene Epoch.”
And it would likely be an “epoch”, said Dr Waters, meaning the current phase of Earth history known as the Holocene has terminated. We would, however, remain within the Quaternary Period and the Cenozoic Era, which are higher rankings in the division of time.
Ten members of the 35-strong working group believe the best spike will probably be plutonium fallout from bomb tests in the 1950s, to be found in marine or lake sediments, ice layers or perhaps even speleothems (stalagmites and stalactites).
Others on the panel, however, think there could be better spikes than the radionuclide. Counter-proposals include remnant plastics or some kind of carbon signature that signifies the rapid rise in CO2 emissions.
Nonetheless, a clear majority of group members (28 of them) accept that whichever marker is chosen, it should reflect events on Earth around the 1950s.
This is the beginning of what is often referred to as the “great acceleration”, when human impacts on our planet suddenly intensified and became global in extent.
George Carlin may have gotten it right, after all.