P ART 2 E MISSIONS ACCOUNTING 13 Net Scottish emissions account: restriction on use of carbon units 30 (1) In section 13 of the 2009 Act— (a) subsections (2) to (4) are repealed, (b) in subsection (5)— (i) in paragraph (a), after “may”, insert “or may not”, and (ii) in paragraph (b), after “may”, insert “or may not”, and 35 (c) after subsection (5), insert— “(5A) But the amount of carbon units purchased by the Scottish Ministers that may, by virtue of regulations under subsection (5), be credited to the net Scottish emissions account for a period is zero, unless regulations under section 13A specify a higher limit in relation to that period.”.