International Review of Waste Management Policy - Department of ...

ut both grow. “Absolute decoupling” means that the economy grows and the
environmental problem declines. “Negative decoupling” implies that the
environmental problem grows faster than the economy (in other words, there is no
decoupling).
The goal of prevention ought to be to achieve absolute decoupling, and to achieve a
reduction in environmental pressure so as to ensure that future environmental quality
is safeguarded, and environmental stocks are effectively managed for the long-term.
The latter is not so easy to define. Hence, an important indicator will inevitably be the
assessment of the degree of decoupling, because of the attention paid in Article 9,
Article 29 (see above) and in the preamble (para 40) of the new WFD (see above).
Point 3 of Annex IV refers to pressure related indicators (see Box 1).
One formulation of a decoupling indicator r(t) for a given year t vis-à-vis a given
reference year t0 is as follows: 9
m(
t)
m(
t0)
r ( t)
=
a(
t)
a(
t )
9
0
where m(t) describes the environmental pressure in year t and a(t) describes the
economic variable in year t (and similarly for time t= t0). In circumstances where the
economic indicator is increasing, positive decoupling can be said to occur when the
decoupling indicator is less than one. Absolute decoupling occurs when the
numerator is less than one even where the economic indicator is greater than one.
There is no decoupling when the indicator equals one. When the decoupling indicator
is greater than one, then where the denominator is greater than one, there is negative
decoupling. These rules have to be reconsidered in the context where the economy is
in decline.
In order to take into account the uncertainty factor in the estimations, a hypothesis
test is needed when trying to determine whether or not there is decoupling. The
uncertainty on the data for an individual production year can be relatively high, which
complicates the estimate of decoupling. For that reason, the numerator and the
denominator in the equation can be replaced by the inclination of a regression line,
which offers greater reliability and robustness than the estimate for a separate year. 10
This methodology has been applied on Flemish data on waste production. Figure 1-1
shows, as an example the decoupling indicator for the total production of industrial
waste compared to the GDP for the periods: 1996-2000, 1997-2001, 1998-2002,
1999-2003, 2000-2004, 2001-2005. 11
9 Mike Van Acoleyen (2004) Indicators for Waste Prevention - Development of a Methodology for, and
Testing of OECD Indicators, OVAM: Mechelen.
10 J. Van Dijck (2004) Hypothese testen van indicatoren voor het afvalstofbeleid, Probabilitas,
Heverlee.
11 OVAM (2008) Bedrijfsafvalstoffen: Cijfers en Trends voor Productie, Verwerking, Invoer en Uitvoer,.
International Review of Waste Policy: Annexes