Landfills, which are part of the solid waste infrastructure, account for about 25 percent  of the methane emissions — or about 2 percent of the total greenhouse gas emissions — in the United States, according to the U.S. Environmental Protection Agency’s 2007 greenhouse gas inventory.

Greenhouse gas emissions can be addressed by lowering upstream impacts (the demand for new materials and products) and by minimizing downstream impacts (such as transporting waste over long distances and disposing of it in landfills.