I have two points.
First, yes, the minister could do this.
Second, of course we'll get to these provisions, but clauses 25 and 26 are relevant to this discussion. Clause 25 requires that the methodology used to report on emissions must be consistent with the methodology we use for our NIRs, and those methodologies are prescribed by the UNFCCC. However, clause 26 allows the GIC to make regulations specifying additional methodologies that might be relevant for clarifying how reporting would be done on emissions and removals to achieve net zero, for example.
That's a long-winded answer, but the short answer is that yes, the minister has the authority to provide all of the descriptions already in the act.