Plastic
now pollutes every corner of Earth
From
supermarket bags to CDs, man-made waste has contaminated the entire
globe, and become a marker of a new geological epoch
Sunday
24 January 2016 00.05 GMT
Humans have made
enough plastic since the second world war to coat the Earth entirely
in clingfilm, an international study has revealed. This ability to
plaster the planet in plastic is alarming, say scientists – for it
confirms that human activities are now having a pernicious impact on
our world.
The research,
published in the journal Anthropocene, shows that no part of the
planet is free of the scourge of plastic waste. Everywhere is
polluted with the remains of water containers, supermarket bags,
polystyrene lumps, compact discs, cigarette filter tips, nylons and
other plastics. Some are in the form of microscopic grains, others in
lumps. The impact is often highly damaging.
“The results came
as a real surprise,” said the study’s lead author, Professor Jan
Zalasiewicz, of Leicester University. “We were aware that humans
have been making increasing amounts of different kinds of plastic –
from Bakelite to polyethylene bags to PVC – over the last 70 years,
but we had no idea how far it had travelled round the planet. It
turns out not just to have floated across the oceans, but has sunk to
the deepest parts of the sea floor. This is not a sign that our
planet is in a healthy condition either.”
The crucial point
about the study’s findings is that the appearance of plastic should
now be considered as a marker for a new epoch. Zalasiewicz is the
chairman of a group of geologists assessing whether or not humanity’s
activities have tipped the planet into a new geological epoch, called
the Anthropocene, which ended the Holocene that began around 12,000
years ago.
Most members of
Zalasiewicz’s committee believe the Anthropocene has begun and this
month published a paper in Science in which they argued that several
postwar human activities show our species is altering geology. In
particular, radioactive isotopes released by atom bombs left a
powerful signal in the ground that will tell future civilisations
that something strange was going on.
In addition,
increasing carbon dioxide in the oceans, the massive manufacture of
concrete and the widespread use of aluminium were also highlighted as
factors that indicate the birth of the Anthropocene. Lesser
environmental impacts, including the rising use of plastics, were
also mentioned in passing.
But Zalasiewicz
argues that the humble plastic bag and plastic drink container play a
far greater role in changing the planet than has been realised. “Just
consider the fish in the sea,” he said. “A vast proportion of
them now have plastic in them. They think it is food and eat it, just
as seabirds feed plastic to their chicks. Then some of it is released
as excrement and ends up sinking on to the seabed. The planet is
slowly being covered in plastic.” In total, more than 300 million
tonnes of plastic is manufactured every year, states the paper, The
Geological Cycle of Plastics and Their Use as a Stratigraphic
Indicator of the Anthropocene.
“In 1950, we
virtually made none at all. It is an incredible rise,” added
Zalasiewicz. “That annual total of 300 million tonnes is close to
the weight of the entire human population of the planet. And the
figure for plastic manufacture is only going to grow. The total
amount of plastic produced since the second world war is around 5
billion tonnes and is very likely to reach 30 billion by the end of
the century. The impact will be colossal.”
As the paper makes
clear, plastic is already on the ocean floor, remote islands, buried
underground in landfill sites and in the food chain. Even the polar
regions, generally considered still to be pristine zones, are
becoming affected. In 2014, researchers found “significant”
amounts of plastic granules frozen in the Arctic Sea, having been
swept there from the Pacific Ocean.
In some cases,
wildlife adapts to the spread of plastic. For example, on islands
such as Diego Garcia, hermit crabs have taken to using plastic
bottles as homes. However, most of the impact on wildlife is harmful.
Creatures ranging from seabirds to turtles become entangled in
plastic and drown or choke to death. “The trouble is that plastic
is very slow to degrade, so we are going to be stuck with this
problem for a long time,” said Zalasiewicz.
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