Waste handling and disposal generates greenhouse gases (GHG) both directly and indirectly.

The most efficient way to reduce direct and indirect GHG emissions in waste management is to reduce waste generation at source, followed by material recycling.

Direct emissions are decreased when waste is not disposed at landfills nor treated in any other way (e.g. combustion).

Indirect emissions can be cut down by decreasing the energy consumption both in acquiring and producing raw material and also in manufacturing the product itself.

It is possible to substitute virgin material with recovered material. In most cases, the replacement of virgin material by recycled material decreases the use of net energy and thus the GHG emissions.

For example, recycling 1 tonne of paper reduces 1 metric tonne of carbon dioxide (CO2 ) equivalent emissions. As a result, use of recycled material in place of fresh material could lead to reduction in GHG emissions.