Commentary on Sections Interpretation Section 93: Measurement of emissions etc by reference to carbon dioxide equivalent
488.This section provides that emissions of greenhouse gases are to be measured or calculated in “tonnes of carbon dioxide equivalent” (defined in subsection (2)); this is to allow for the differing relative forcing effects and atmospheric lifetimes of differing greenhouse gases – for example, over 100 years, a tonne of methane has 23 times the global warming effect of carbon dioxide. These factors are known as “global warming potentials”, and are to be calculated consistently with international carbon reporting practice (defined in section 94).