3 June 2021
The Earth is
groaning under the weight of the increasing destruction of ecosystems. If the
boundaries are reached of what the Earth can bear, ecological restoration is no
longer possible. Nine planetary boundaries have been defined. They include
climate change, overfishing and large scale deforestation.
There is now enough evidence to recognise plastic pollution as the tenth planetary boundary, assert researchers in the journal Environmental Science and Technology.
PLASTIC POLLUTION AS A PLANETARY BOUNDARY
The Stockholm Resilience Centre has recognised nine planetary boundaries for the Earth. Plastic pollution must meet three criteria to be recognised as a planetary boundary. There is great consensus about two of the three: plastic in the environment is irreversible (it cannot be or can hardly be cleaned); and plastic is pervasive. Over the last couple of years, the scientific discussion has centred around the question of whether it meets the third criterion of having a disruptive effect on the Earth’s system.
TWO IMPORTANT PHENOMENA
In the article that has now been published, the authors
assert that there is enough evidence to show that plastic does have a
disruptive effect on ecosystems. They point to two phenomena: the fragmentation
processes and the leakage of chemical substances into the environment. As, at
the same time, the amount of plastic in the sea is increasing, these phenomena
could lead to the critical boundaries being exceeded in the future.
CONTINUOUS FRAGMENTATION
Plastic is subject to all sorts of fragmentation mechanisms.
For example, plastic breaks up in sunlight, breaking down into smaller and
smaller pieces that can never be removed from the ecosystem. This process can
go remarkably quickly. The authors refer to research that determined that by releasing
millions of micro and nanoparticles, a 4 mm thick piece of Styrofoam lost 5% of
its weight within one month.
CHALLENGE
While the authors say that it is essential to define the
boundary’s criteria, they recognise that this is a huge challenge given that
the mechanisms are so complex. Research in natural conditions is extremely
difficult to carry out. Furthermore, there is no agreement about measuring and
monitoring methods. This makes the outcomes of research very hard to compare.
The implication is that the boundaries may be exceeded before they are even
defined.
But we should not delay taking action until there is
complete consensus about the boundaries. The world should take preventive
action as quickly as possible to avoid further plastic pollution. This message
is close to Plastic Soup Foundation’s heart.
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