Zero Waste by Robin Murray, Greenpeace Environmental Trust 2002

disposal. The issue of toxicity is a shadow over the present
management of waste that will not go away.
Climate change
If waste is a threat, it is now also seen as an opportunity –
nowhere more so than in relation to climate change. At
one level, it is a question of cutting emissions – of
methane in the case of landfill or of carbon dioxide
(C0 2 )and oxides of nitrogen (NOx) in the case of
incineration. Equally significant is the potential
contribution of waste management in displacing other
global warming activities and in acting as a carbon sink.
In the words of the US Environmental Protection Agency
(EPA) in 1998:
“Among the efforts to slow the potential for climate
change are measures to reduce emissions of carbon
dioxide from energy use, reduce methane emissions and
change forestry practices to promote long-term storage of
carbon in trees. Different management options for
Municipal Solid Waste provide many opportunities to
affect these same processes, directly or indirectly.” 13
Of these, the most significant is the opportunity to retain
the energy embodied in waste products by reuse and
recycling. One quarter of greenhouse gas (GHG) emissions
stem from the life cycle of materials. Any substitution of
the demand for primary materials by the reuse and
recycling of secondary materials and discarded products
stands to contribute significant savings in energy and the
resulting emissions. 14
One estimate of the savings has been made for the USA in
an exhaustive study by the USEPA. In the USA, nearly half
the municipal waste is accounted for by five materials –
p a p e r, steel, aluminium, glass and plastic. The virg i n
p roduction of these materials consumes one third of all
manufacturing industry ’s energy consumption. According to
the USEPA study, recycling these materials rather than
disposing of them by landfill or incineration would result in
savings of 0.8 metric tonnes of carbon equivalent (MTCE)
for every tonne of waste diverted, or 17 million MTCE for
each 10% of municipal waste diverted from disposal. 1 5
For the UK, the intensive diversion of waste from disposal
has a similarly striking impact. One model that used the
USEPA data on relative CO2 effects found that the reuse
and recycling of 70% of the UK’s municipal waste would
lead to a saving of 14.8 million MTCE, which would have
a similar impact to taking 5.4 million cars off the road. 16
If this was repeated for commercial and industrial waste,
the total savings would amount to nearly a third of the
reductions (over and above existing measures) that would
be necessary for the UK to meet its target of 20% cuts in
CO2 by 2010. This is one measure of the significance of
waste diversion within the context of the Kyoto protocol. 17
There are two other ways in which the form of waste
management can reduce net CO2 emissions. The first is
the impact of using composted biodegradable waste on
land as a soil amendment and, in doing so, ‘sequestering’
carbon from its everyday cycle. Applying compost acts as
a counterweight to the release of stored-up carbon in soils
resulting from depletion induced by intensive agriculture.
This is an area of increasing scientific interest in the
context of agricultural and climatic sustainability. One
estimate is that 20 billion tonnes a year of carbon are
captured in the soil’s organic matter, compared with 80
billion tonnes of anthropogenic carbon emitted to the
atmosphere. 18 In Italy, Favoino cites evidence to suggest
that an increase of 0.15% of organic carbon would lock
the same amount of carbon into soil biomass as is released
annually into the atmosphere by the use of fossil fuels in
Italy. 19 The significance of composting for carbon
sequestration in soils was recognised by the recent Bonn
Conference on Climate Change and is becoming an
increasing influence in EU policy.
The other potential impact of waste management on CO2
reduction is more controversial, based as it is on the
production of power (and in some cases heat) from
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