Professor David C. Wilson
Waste & Resources Management Consultant
Visiting Professor in Waste Management
Imperial College, London

Waste and climate – an opportunity

STOP PRESS: DCW has been invited to speak at the All-Party Parliamentary Sustainable Resource Group (apsrg) seminar on ‘COP21 and Waste: Exploring the Resource Industry’s Potential of Contributing to Climate Change Mitigation’ at Westminster on 10 December 2015.

POSTED 09 November, 2015. In the run-up to the Paris summit on climate change, the search is on for short and medium term opportunities to achieve significant reductions in greenhouse gas (GHG) emission across the economy. Several recent reports have pointed to the potential for improved waste and resource management as one such ‘entry point’. Some major developed economies have already reduced total GHG emissions by 5% through reduction of methane emissions from landfill. Tackling food waste could reduce global GHG emissions by 9%. Overall, the recent UNEP Global Waste Management Outlook (edited by DCW) has estimated that improved waste and resource management has the potential to save 15-20% of global GHG emissions across the economy.

Waste management is a cross-cutting issue impacting on many aspects of society and the economy. The link between waste and climate is particularly important. Waste management is generally considered a small but important contributor to GHG emissions. Its direct contribution through methane (CH4) emissions from anaerobic decomposition of organic wastes at disposal sites was estimated by the Intergovernmental Panel on Climate Change (IPCC) at around 3% of total GHG emissions in 2010. However, this figure grossly underestimates the potential contribution of improved waste and resource management to global GHG mitigation, both because it ignores savings already made prior to 2010, and because the IPCC has used a very narrow definition of the ‘waste sector’.

Planet-wide MSW generation in 2010 was dominated by high-income countries, which had already substantially reduced methane emissions from landfills. For example, changes in Germany’s waste sector between 1990 and 2006 reduced the country’s total GHG emissions by 5% , and this was in addition to the significant mitigation of methane emissions already achieved prior to 1990.

The IPCC sector estimates are necessarily carefully segmented to avoid any possibility of double counting. So their estimate also omits those emissions displaced through waste prevention, reuse, recycling and biogenic energy recovery, as these occur outside of the ‘waste sector’ – a point which has also been highlighted in a recent report prepared for Zero Waste Europe. An earlier study for the German government, using a life cycle approach, estimated that a 10-15% reduction in global GHG emissions could be achieved through improved solid waste management, including landfill mitigation and diversion, energy from waste and recycling.

Including waste prevention could further increase this estimate. An on-going UN project estimates that 1.3 billion tonnes of edible food waste is generated every year, representing one third of all food produced for human consumption. Prevention of this food waste would reduce total global GHG emissions by an amazing 9%: more than the total emissions of any country other than the US and China.

Overall, the GWMO concludes that the potential impact of improved waste and resource management on reducing GHG emissions across a broad range of economic sectors could be 15-20%.