|Incredible impact on the environment (Kevin Gill/flickr/cc)|
Changes to the Earth system that characterize the potential Anthropocene Epoch include marked acceleration to rates of erosion and sedimentation; large-scale chemical perturbations to the cycles of carbon, nitrogen, phosphorus, and other elements; the inception of significant change to global climate and sea level; and biotic changes such as unprecedented levels of species invasions across the Earth. Many of these changes are geologically long-lasting, and some are effectively irreversible. These and related processes have left an array of signals in recent strata, including plastic, aluminium and concrete particles, artificial radionuclides, changes to carbon and nitrogen isotope patterns, fly ash particles, and a variety of fossilizable biological remains. Many of these signals will leave a permanent record in the Earth's strata."Being able to pinpoint an interval of time is saying something about how we have had an incredible impact on the environment of our planet," said Colin Waters, principal geologist at the British Geological Survey and secretary for the working group. "The concept of the Anthropocene manages to pull all these ideas of environmental change together."
Indeed, the Guardian compiled more "evidence of the Anthropocene," saying humanity has:
- Pushed extinction rates of animals and plants far above the long-term average. The Earth is now on course to see 75% of species become extinct in the next few centuries if current trends continue.
- Increased levels of climate-warming CO2 in the atmosphere at the fastest rate for 66m years, with fossil-fuel burning pushing levels from 280 parts per million before the industrial revolution to 400ppm and rising today.
- Put so much plastic in our waterways and oceans that microplastic particles are now virtually ubiquitous, and plastics will likely leave identifiable fossil records for future generations to discover.
- Doubled the nitrogen and phosphorous in our soils in the past century with our fertilizer use. This is likely to be the largest impact on the nitrogen cycle in 2.5bn years.
- Left a permanent layer of airborne particulates in sediment and glacial ice such as black carbon from fossil fuel burning.
The Guardian points out: "For the Anthropocene, the best candidate for such a golden spike are radioactive elements from nuclear bomb tests, which were blown into the stratosphere before settling down to Earth." However, Jan Zalasiewicz, a geologist at the University of Leicester and chair of the working group, told the paper that while "the radionuclides are probably the sharpest - they really come on with a bang," humanity has left no shortage of signatures. "We are spoiled for choice," he said. "There are so many signals."
According to the Telegraph, once one or more golden spike sites have been selected, a proposal for the formal recognition of an Anthropocene epoch will be made to a series of commissions, culminating at the International Union of Geological Sciences. The process is likely to take at least three years.