13The net Scottish emissions account
(1)The net Scottish emissions account means the aggregate amount of net Scottish emissions of greenhouse gases—
(a)reduced by the amount of carbon units credited to the net Scottish emissions account for the period in accordance with regulations under subsection (5);
(b)increased by the amount of carbon units that, in accordance with such regulations, are to be debited from the net Scottish emissions account for the period.
(2)The net amount of carbon units credited to the net Scottish emissions account for a year for which an annual target has been set (a “target year”) must not exceed the allowable amount.
(3)The “allowable amount” is—
(a)the amount equal to the limit, set by virtue of section 21(1), on the net amount of carbon units that may be credited to net Scottish emissions accounts during the period which includes the target year; or
(b)where a net amount of carbon units has been credited to the net Scottish emissions account for any other target year in that period, the balance (if any) remaining of the amount referred to in paragraph (a).
(4)In subsections (2) and (3), the “net amount of carbon units” has the meaning given by section 21(3).
(5)The Scottish Ministers may, by regulations, make provision about—
(a)the circumstances in which carbon units may be credited to the net Scottish emissions account for a period;
(b)the circumstances in which such units may be debited from that account for a period;
(c)the manner in which this is to be done.
(6)The regulations must contain provision for ensuring that carbon units that are credited to the net Scottish emissions account for a period cease to be available to offset other greenhouse gas emissions.