EMISSIONS FROM WASTE

A significant by-product of waste disposal is gas emissions into the atmosphere. When organic waste decomposes in landfills, it releases methane and other greenhouse gases, contributing to climate change. Similarly, greenhouse gases can also be emitted during the treatment and processing of wastewater and sewage, or during the incineration of waste.

Recent years have seen significant declines in the total volume of greenhouse gases emitted by the waste sector. Between 1990 and 2008, net emissions from the waste sector declined by 20%. The waste sector's contribution to Australia's total greenhouse inventory has also declined, from 4.3% in 1990 to 2.6% in 2008 (DCCEE 2010).

Declines in waste emissions have been largely due to increases in the volume of greenhouse gases captured at Australia's landfills. In 1990, less than one percent of all landfill emissions were recovered. By 2008, this figure had increased to 28%. During this same period, the total volume of emissions being generated at Australian landfills only experienced a moderate increase (8%). Consequently, net emissions from Australian landfills has fallen by 22% between 1990 and 2008 (from 14.2 million tonnes of carbon dioxide equivalent emissions to 11.1 million tonnes).

Gas captured at Australian landfills can be utilised for many different purposes. Most is used as a fuel for electricity generation, but it can also be used to fuel nearby industrial facilities, or purified and sold to gas providers.