Commentary on Sections Interpretation Section 92: Meaning of “greenhouse gas”
485.This section defines the term “greenhouse gas” to include:
	carbon dioxide (CO2);
	methane (CH4);
	nitrous oxide (N2O);
	hydrofluorocarbons (HFCs);
	perfluorocarbons (PFCs);
	sulphur hexafluoride (SF6).
486.The definition of greenhouse gases follows that used in the Kyoto Protocol. Note that the term “targeted greenhouse gas”, used in relation to the targets and budgets in Part 1 of the Act, is defined separately in section 24; for the time being, the lists of gases are identical.
487.Subsections (2) to (4) give the Secretary of State a power to amend the definition of “greenhouse gas” by negative resolution order. But the power can only be exercised if the Secretary of State considers that an international agreement has been reached which recognises that the gas contributes to climate change.