TCoPS - 38

multiplied the waste management cost per tonne
(US$125.68) by the tonnes of plastic produced in 2019
that becomes waste (257.6 million). This uses the cost per
tonne of municipal solid plastic waste as a proxy for a cost
per tonne of plastic waste overall and uses the cost per
tonne of waste in 2016 as a proxy for the cost per tonne
of waste in 2019. This estimated the cost of waste
management for the plastic produced in 2019 as
~US$32 billion.278
3. Ecosystem service cost of plastic pollution on
marine ecosystems:
● The following inputs were used to estimate the
ecosystem service cost of the plastic produced in
2019:
ocean in 2011 estimated by Constanza et al. as◦ Input 1: Value of ecosystem services provided by the
While there are other papers
~US$49.7
trillion in 2007 dollars.279
on the importance of marine ecosystem services, Costanza
et al. provide a value for global ecosystem services which
is based on a figure from Costanza et al. 1997280
using
updated ecosystem service values and land use change
estimates and updated data. They also respond to
criticisms of the 1997 paper to increase the robustness of
their valuation.
◦ Input 2: Reduction in ecosystem services because
of marine plastic pollution estimated by Beaumont et al.
as between 1-5%.281
This was based on an expert scientific
panel reviewing available evidence on the damage imposed
by plastic on each ecosystem service. This includes damage
posed by plastic on all regulating, cultural and regulatory
services provided by the ocean. Only where sufficient
evidence was available were reductions estimated.
◦ Input 3: Stock of plastic in the ocean in 2011
estimated by Beaumont et al.282
million283-150 million tonnes.284
as between 75
◦ Input 4: Time horizon of plastic pollution in the
ocean assumed to be infinity. This is based on the fact
that most plastics will remain permanently in the ocean
continuing to break down into smaller and smaller
particles and plastic continues to cause harm regardless of
how small a piece it becomes. More research is emerging
that outlines the harmful impacts of micro and nanoplastic.
However, in the methodology, due to the use of a discount
rate (see input 5), 85% of the lifetime cost comes from the
costs incurred in the first 100 years, and 95% from the
costs incurred in the first 150 years; The costs incurred
after the first 200 years are being discounted by more than
98% and do not significantly contribute to the lifetime cost
estimates.
based on Drupp◦ Input 5: Social discount rate (SDR) estimated as 2%
were comfortable with a median SDR of 2%. 285
et al. where more than 2/3 of 200 experts
◦ Input 6: Plastic production in 2019 estimated by
PlasticsEurope Market Research Group (PEMRG) and
Conversio Market & Strategy GmbH as 368 million
metric tonnes.286
◦ Input 7: Proportion of the plastic produced in
WWF INTERNATIONAL 2021
2019 that becomes waste estimated as 70%. This is based
on a study by Geyer et al.287
that estimated 70% of the
cumulative plastic produced between 1950-2015 has
become waste. The authors of this report also assumed that
this proportion has remained constant over time.
◦ Input 8: Tonnes of municipal solid plastic waste and
primary microplastics288
that leaked into the ocean in 2016
estimated as 11.1 million tonnes in Breaking the Plastic
Wave.289
◦ Input 9: Tonnes of fishing gear that leak into the
ocean annually estimated as 0.6Mt by Boucher and
Friot.290
◦ Input 10: Proportion of at-sea based sources of
leakage into the ocean accounted for by fishing gear
estimated as 65% as per Arcadis 2012,291
the other 35%
coming from shipping which could be domestic waste from
the ship, leaked cargo, or ropes.
by Geyer ◦ Input 11: Plastic waste generated in 2015 estimated
et al.292 as 302 million tonnes.
● The following steps were taken to estimate the
ecosystem service cost of the plastic produced in
2019:
Step 1: The authors converted the value of marine
ecosystem services in 2011 in 2007 US$ into 2019 US$
using data on the U.S consumer price index from The
U.S. Labor Department's Bureau of Labor Statistics. This
estimated the value of ecosystem services in 2011 in 2019
US$ as ~US$61.3 trillion.
Step 2: To estimate the minimum cost imposed by plastic
pollution in the ocean in 2011, the authors took 1% of $61.3
trillion (i.e., the most conservative end of the 1-5% range
from the Beaumont et al. paper293
). This estimated the
minimum cost imposed by plastic pollution in the ocean as
~US$613 billion.
Step 3: To estimate the cost per tonne of plastic pollution,
the authors divided the cost imposed by plastic pollution
in the ocean ($613 billion) by the lower bound and upper
bound stock of plastic in the ocean (75 million and 150
million). This estimated the minimum cost per tonne as
between ~US$4,085-8,171. This estimate is an average
cost per tonne of plastic. However, in reality the cost per
tonne will change depending on the type and size of the
plastic, where the plastic was emitted from and where it
moves to. Therefore, each tonne of plastic in the ocean is
likely to have a cost that is either greater or smaller than
the average based on these factors.
Step 4: Several of the main contributors to plastic waste
that end up in the ocean can take more than 400 years to
degrade, with research showing that plastic can remain in
the ocean for thousands of years. Therefore, plastic waste
will generate costs for societies and governments for at
least several hundreds and even potentially thousands of
years. However, given the uncertainty of estimating costs
in the future, the authors built this model conservatively.
They used a perpetual net present value formula to
estimate the lifetime cost per tonne of plastic in the ocean.
A net present value formula calculates the present value of
a future stream of costs which discounts the future costs

TCoPS

Table of Contents for the Digital Edition of TCoPS