A new study warns that the Earth's surface is being noticeably altered by the production of long-lasting man-made materials, resulting in an 'age of plastic.' The research suggests that plastics have such a long-lasting impact on the planet's geology because they are inert and hard to degrade.
"Plastics are pretty well everywhere on Earth, from mountain tops to the deep ocean floor -- and can be fossilised into the far future," said Jan Zalasiewicz, professor of palaeobiology from University of Leicester's department of geology.
‘If all the plastic made in the last few decades was clingfilm, then there would be enough to put a layer around the whole Earth.’
"We now make almost a billion tonnes of the stuff every three years. If all the plastic made in the last few decades was clingfilm, there would be enough to put a layer around the whole Earth. With current trends of production, there will be the equivalent of several more such layers by mid-century," Zalasiewicz informed.
Plastics can travel thousands of miles, caught up in the 'great oceanic garbage patches', or eventually being washed up on distant beaches. Plastics can eventually sink to the sea floor, to become a part of the strata of the future.
Their distribution in both the terrestrial and marine realms suggests that they are a key geological indicator of the Anthropocene, an epoch where humans dominate the Earth's surface geology, as a distinctive stratal component.
"Plastics will continue to be input into the sedimentary cycle over coming millennia as temporary stores -- landfill sites -- are eroded," Zalasiewicz said in a paper published in the journal Anthropocene
"Plastics already enable fine time resolution within Anthropocene deposits via the development of their different types and via the artefacts, known as 'technofossils', they are moulded into, and many of these may have long-term preservation potential when buried in strata," the authors wrote.
Zalasiewicz's team included University of Leicester professor Mark Williams and research student Yasmin Yonan from the department of geology and field archaeologist Matt Edgeworth, an honorary visiting research fellow from the varsity's school of archaeology and ancient history.