Many cities now have recycling programs in place to deal with the waste generated by industrial and commercial operations as well as residential waste streams. Nevertheless, a significant amount of waste is still being directed to landfill sites. Much of the waste that is sent to these landfill sites is organic matter or derived from organic matter and, as such, produces landfill gases as it decomposes. (Source: Canada's Greenhouse Gas Inventory, 1990-2000)
Much of the gas produced is methane. Methane (CH4) is regarded as one of the most important Green House Gasses (GHGs) because its global warming potential has been estimated to be more than 20 times of that of carbon dioxide (CO2) and atmospheric methane concentration has been increasing in the range of 1–2% per year (IPCC, 2007a).
Canada has over 10,000 landfill sites and, in 2000, solid waste disposal on land accounted for 3 percent of Canada's total GHG emissions and was responsible to 25 percent of Canada's total methane emissions (Environment Canada's Greenhouse Gas Inventory, 1990-2000). The Environmental Protection Agency states that, in the U.S., landfills accounted for approximately 22 percent of total methane emissions in 2008 — their second largest source.
Management of GHGs is becoming more important to communities across the country. To see how Fredericton, New Brunswick has turned the city’s landfill into a source of carbon credits, please click on the link below: