Skip to main content.

Archived publication

This publication is no longer current or has been superseded.

Waste sector

Greenhouse gas emissions from waste are predominantly methane, formed as organic wastes such as food decay. Small amounts of nitrous oxide are also generated from incineration of solvents and decomposition of human waste. Carbon dioxide emissions from the breakdown of organic material are not reported because the carbon dioxide emitted is assumed to be reabsorbed by growth in vegetation and other organic matter in the following year.

Figure 9: Waste sector emissions: 2005

Thumbnail of image. See figure at its full size including text description.

Waste emissions were 1.8 Mt CO2-e in 2005, a decrease of 0.6 Mt CO2-e (26 per cent) since 1990. This decrease is due to improved processing and the capture of landfill gas from solid waste disposal. The waste sector contributed 2 per cent to New Zealand’s total greenhouse gas emissions in 2005.

Solid waste disposal on land represented 79 per cent (1.5 Mt CO2-e) of waste sector greenhouse gas emissions in 2005. This is a reduction of 29 per cent since 1990 (2.1 Mt CO2-e).

Wastewater handling makes up the remaining 21 per cent (0.4 Mt CO2-e) of emissions from the waste sector. Emissions from wastewater are largely driven by changes in human population.