Opportunities for Reducing Greenhouse Gas Emissions through Residential Waste Management

All human activities have an environmental impact. In particular, the way we choose to manage our
residential solid wastes has a direct impact on the generation of methane, carbon dioxide and other
greenhouse gases (GHG) linked to global warming and climate change. This report provides decisionmakers
with a quantitative, comparative assessment of the currently practicable waste management
options in terms of their potential generation of GHG. The analysis is based on representative Canadian
waste generation data, and employs a streamlined, yet rigorous, life cycle methodology developed for
the U.S. Environmental Protection Agency (U.S. EPA). Additional waste management data used in the
analysis has been compiled by the technical staff of the Environment and Plastics Industry Council
(EPIC). Information on anaerobic digestion has been taken from work conducted by Environment
Canada.
If all the residential waste in Canada were landfilled, food wastes would generate the greatest amount of
GHG, followed by office paper, mixed paper, and corrugated box board. In comparison, the emissions
related to the landfilling of metal, glass and plastics are insignificant. In order to achieve the greatest
possible reductions in GHG emissions, waste managers should address the materials present in the
waste stream in the largest quantities. For example, a one percent increase in the recycling of paper
products is equivalent to tripling the recycling rate for some plastics. Redirecting food wastes to
composting would reduce GHG emissions by 210,000 metric tonnes of carbon equivalent (or 780,000
tonnes of carbon dioxide) per year. The anaerobic digestion of food waste in a closed vessel to produce
methane would provide even greater benefits.