Geologists, climate scientists, ecologists – and a lawyer – gather in Berlin for talks on whether to rename age of human life
The question confronting the scientists and other specialists is straightforward enough, even if the solution is far from simple. Is it time to call an end to the epoch we live in and declare the dawn of a new time period: one defined by humanity’s imprint on the planet?1
BERLIN — I just participated2 in the first face-to-face meeting of the Anthropocene Working Group, a subset of a branch of the International Commission on Stratigraphy examining whether humanity’s growth spurt (in both numbers and resource appetites) has caused sufficient change to Earth systems to leave a discernible trace in layered rocks that will build and endure far into the future.
Here’s another way to frame the question: Have we left the Holocene Epoch — the warm interval since the end of the last ice age some 10,000 years ago — and entered what is increasingly described as a geological epoch or age of our own making? (A 2011 paper, “The Anthropocene: conceptual and historical perspectives,” is the best scientific overview; also read this fine Paul Voosen story on the Anthropocene concept.)
As Ian Sample reported in The Guardian, some geologists frown on the idea:
Phil Gibbard, a geologist at Cambridge who set up the working group in the first place, is one. “ I’m not in favour of this being defined formally as a division of geological time. I think it’s an extraordinarily difficult thing to do,” he said. “We are living in an interglacial period and there’s no question we’re still within that period, and it’s called the holocene.”
But the consensus of those gathered on Thursday was clearly in support of the Anthropocene, although there are still plenty of questions to answer — like whether it’s an age within the Holocene or a new geological epoch in its own right, and when it started. ...
“It’s not research, it is diplomacy. It’s not necessary for geologists,” says Lucy Edwards, a researcher with the U.S. Geological Survey. Others think there is a case to be made for at least trying to codify the Anthropocene, because it is forcing the global community to think about the true extent of human influence. "It focuses us on trying to work out how we measure the relative control of humans as opposed to nature," says Tony Brown, a physical geographer at the University of Southampton in the United Kingdom.
"For example, is human activity altering the rate of uplift of mountains? If you had asked that question 20 years ago, geologists would have looked at you as if you were mad," says Brown. "But we know some faults are lubricated by precipitation, so if we are altering global precipitation patterns, there is a slight chance of a link. If that is the case, that is quite a profound potential interaction between humans and their environment."
The International Commission on Stratigraphy—the ruling body that sets formal boundaries on geologic ages—has set up a working group to study the case for making the Anthropocene official. The crux of the debate is where to place the starting boundary line, or base. Geologists continue to tinker with the bases for well-established epochs, eras and ages, and there is usually a relatively wide margin of error. "Even the most precisely defined, the end of the Cretaceous 66 million years ago, is plus or minus 3,000 years. This is minute in geological terms but very big in humans terms," says Brown.
In the reference text "The Geologic Time Scale 2012", Crutzen and colleagues lay out three main options for the start of the Anthropocene. It's possible to set the boundary in the early part of the current epoch, called the Holocene, which began about 11,700 years ago. The idea is that the dawn of agriculture in the early Holocene kicked off a steady rise in carbon dioxide that has altered Earth's natural climate cycles. But that potential base is controversial, in part because agriculture spread to various locations at different times, and a formal interval of geologic time should be recognizable globally.3
- 1. Source: http://www.theguardian.com/science/2014/oct/16/-sp-scientists-gather-talks-rename-human-age-anthropocene-holocene
- 2. Source: http://dotearth.blogs.nytimes.com/2014/10/16/does-the-anthropocene-the-age-of-humans-deserve-a-golden-spike/?_php=true&_type=blogs&_r=0
- 3. Source: http://www.smithsonianmag.com/science-nature/have-humans-really-created-new-geologic-age-180952865/#hH6KJkRTdZxOZDDD.99