The climate change phenomenon, its causes and consequences, is now generally accepted and recognised by the international scientific community, governments, the private sector, NGOs and the general population.
It requires a robust response. Solutions must be found that will mitigate emissions of greenhouse gases and help to adapt to its unavoidable consequences. The complexity of the issue requires the acceptance of a common responsibility from both the public and private sector.
The waste industry occupies a unique position as a potential reducer of greenhouse gas (GHG) emissions. As industries and countries worldwide struggle to address their carbon footprint, waste sector activities represent an opportunity for carbon reduction which has yet to be fully exploited.
The waste sector offers a portfolio of proven, practical and cost effective technologies which can contribute to GHG mitigation. When adapted and deployed according to local traditions and needs, they can help secure significant global GHG emission savings.
The global direct GHG emissions resulting from waste management activities are around 1.3Gt CO2 eq. or approximately 3 – 5% of total anthropogenic emissions in 2005 (IPCC 2007). However, there is now credible evidence that, taking into account associated avoided emissions, the waste sector can completely change this picture.
Through aerobic and anaerobic biological treatment technologies, organic wastes can be recovered and transformed into soil conditioners and fertilisers. These processes reduce GHG emissions by sequestering biogenic carbon in soils, improving soil physical properties, and adding soil nutrients.
The organic component of waste (e.g. paper, cardboard, food waste or garden waste) ranges from 30-70% of total municipal waste production. If collected separately, it can offer a valuable contribution to GHG emissions reduction and soil improvement.
Organics recovery is particularly effective where soil and organic matter are being eroded due to deforestation, cultivation practices, or as a consequence of climate change.
Anaerobic technologies provide an added energy benefit.
Waste offers a significant source of renewable energy. Incineration and other thermal processes for waste-to-energy, landfill gas recovery and utilisation, and use of anaerobic digester biogas can play important roles in reducing fossil fuel consumption and GHG emission.
Accurate measurement and quantification of GHG emissions is vital in order to set and monitor realistic reduction targets at all levels. Current methodologies form a valuable database for assessment of GHG emissions from waste activities, however, improvements are required to adequately represent the full lifecycle of materials and energy.
- IPCC national waste GHG inventory methodologies estimate direct emissions, but do not include indirect emissions and environmental benefits, especially those which impact other sectors.
- Improved, harmonised and transparent approaches for both the direct and indirect emissions associated with waste management activities must be developed to complement existing methodologies.
- More consistent and coordinated data collection is needed to support the improved methodologies and reduce accounting uncertainties.
More about Waste and Climate Change at ISWA.