Methane and Other Non-C02
Pollutants Have Role in Closing Emissions
Gap
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in Cancun
Cancún (Mexico), 3 December
2010 - Cutting emissions from the global
waste sector, including the potent greenhouse
gas methane, could play a part in combating
climate change, says a new report released
today.
The waste management
sector is contributing 3-5 per cent of global
man-made greenhouse gas (GHG) emissions,
equal to around the current emissions from
international aviation and shipping, according
to some estimates.
But the report says
the waste sector is in a strong position
to move from being an emissions source to
being a major emissions saver, in part by
harvesting the methane from rubbish tips
for fuel and electricity generation.
In doing so the sector
can play a role in bridging the gap between
where emissions need to be in 2020 and where
emissions are heading under the various
pledges associated with the 2009 Copenhagen
Accord.
According to the recent
Emissions Gap Report, presented in advance
of the UN Climate Change Conference in Cancun
by UNEP and researchers from 25 modelling
centres, a best-case scenario would see
emissions fall to around 49 gigatonnes (Gt)
of C02 equivalent, if the Copenhagen pledges
are fully implemented.
Scientists estimate
that emissions need to be as low as 44 Gt
in 10 years' time to stand a good chance
of keeping a 21st century temperature rise
to under 2°C.
Accelerated action on
C02 emissions will be key to bridging this
5 Gt gap. But this could be assisted by
greater action on a range of non-C02 pollutants
ranging from black carbon and nitrogen compounds
to methane.
"Every avenue,
every opportunity and every option for cutting
greenhouse gases needs to be brought into
play if the world is to combat dangerous
climate change and set the stage for a transition
to a low-carbon, resource-efficient Green
Economy urgently needed in the 21st century,"
said Achim Steiner, UNEP's Executive Director
and Under Secretary General of the UN.
"The waste sector
is already acting to minimize the impacts
of potentially potent greenhouse gases like
methane, but this is often done on a country-by-country
basis. The time is ripe to scale up and
deliver a far more coordinated and global
response, especially in respect to developing
economies. This offers multiple benefits
ranging from curbing greenhouse gas emissions
to generating new green jobs and increased
access to energy from waste-into-electricity
projects," he added.
The report, Waste and
Climate Change: Global Trends and Strategy
Framework, was prepared by the United Nations
Environment Programme's International Environmental
Technology Centre, based in Japan. The authors
examine the contribution the waste sector
can make in the fight against climate change
and suggest a strategy for increasing this
contribution.
The report lists three
main areas in which GHG savings can be made
in the waste sector:
- Reducing the amount
of primary materials used in manufacturing
through waste avoidance and material recovery
through recycling (avoiding the GHG emissions
from the energy used to extract or produce
the primary materials)
- Producing energy from
waste to replace energy from fossil fuels
- Storing carbon in
landfills and through the application of
compost to soils
But the study also underlines
that much work remains to fully estimate
the potential emissions contribution - and
thus possible emissions savings - from the
waste sector because in many countries data
can be patchy and methods of calculating
waste-related pollution vary between nations.
Indeed the report notes
that levels of uncertainty can be as high
as 10-30 per cent for developed countries
(with good data sets) to more than 60 per
cent for developing countries that do not
have annual data.
Methane emissions from
landfills are generally considered to represent
the biggest impact on the climate from the
waste sector, followed by incineration of
waste. Methane is generated in landfills
when microbes form and begin to break down
organic matter, such as food, paper, wood
or garden trimmings.
A roughly even mix of
carbon dioxide and methane gas forms during
the decomposition process, but the practice
in some locations of burying or covering
waste can result in a greater proportion
of methane being produced. When that methane
escapes into the atmosphere it is thought
to have a global warming potential 25 times
that of carbon dioxide over 100 years.
Landfills that have
gas recovery systems in place capture the
methane and convert it into fuel and compost.
Capture rates vary from landfill to landfill
(because they depend on the mix of the materials
dumped in them) but estimates from managed
landfills in developed countries put capture
rates at 50-80 per cent.
One study quoted in
the report suggests emissions savings of
132-185 kg CO2 equivalent per tonne of wet,
mixed municipal solid waste input stored
in well-managed, European landfills. Another
study suggests that simply by diverting
food, garden and paper waste to composting
or recycling stations, thereby reducing
the amount of organic matter in landfills,
emissions could be cut by 250kg CO2-equivalent
per tonne of municipal solid waste.
For example, Germany,
between 11000 and 2005, gradually banned
untreated organic waste in landfills. By
2012, it is expected that this will have
avoided 28.4 million tonnes of CO2-equivalent
of methane emissions.
The report estimates
that in many developing countries, the level
of organic waste (and thus a potential source
of methane emissions) is around 50 per cent
and could, in a rapidly developing country
such as China, represent more than half
of the waste stream up to and beyond 2030
if no action is taken.
The report notes that
handling of greenhouse gases in the waste
sector needs to be considered in the light
of other environmental, social and economic
implications of waste management strategies,
which will differ from location to location.
Although average annual
per capita waste generation in developing
countries is estimated at 10-20 per cent
of that of developed countries, this figure
is rising in response to economic and population
growth. One of the key challenges is to
decouple waste production from economic
growth. Some of the world's poorest countries
have difficulty accessing finance and technology
to implement waste management and recovery
programmes although some projects are being
fast-tracked with support under the Kyoto
Protocol and its Clean Development Mechanism
(CDM).
A separate assessment
by UNEP's Risoe Centre in Denmark estimates
that around 320 (or just under 6 per cent)
of CDM projects in the pipeline are related
to landfill gas.
This, according to experts,
is just the "tip of the iceberg"
in terms of the potential. China for example
produces 254 million tons of refuse a year
yet only 2.5 per cent of all CDM projects
in China are landfill ones. In India just
under two per cent of CDM projects are landfill.
The Executive Secretary
of the Basel Convention, Ms Katharina Kummer
Peiry, supported the Waste and Climate Change
report. "I welcome this report as a
basis for addressing the ways in which waste
management can help combat climate change,
an important issue that has so far been
underestimated. The Secretariat looks forward
to joining forces with others in strengthening
this link through the environmentally sound
management of waste," she said.
Notes to Editors:
The full report can be downloaded from:
http://www.unep.or.jp/Ietc/Publications/spc/Waste&ClimateChange/Waste&ClimateChange.pdf
The Basel Convention
on the Control of Transboundary Movements
of Hazardous Wastes and their Disposal is
the most comprehensive global environmental
agreement on hazardous and other wastes.
For more information see www.basel.int
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