Calculating GHG emissions.

(a) Except as provided in paragraph (b) of this section, continue to monitor and report CO 2 mass emissions as required under § 75.13 or section 2.3 of appendix G to 40 CFR part 75, and § 75.64. Calculate CO 2 , CH 4 , and N 2 O emissions as follows: (1) Convert the cumulative annual CO 2 mass emissions reported in the fourth quarter electronic data report required under § 75.64 from units of short tons to metric tons. To convert tons to metric tons, divide by 1.1023. (2) Calculate and report annual CH 4 and N 2 O mass emissions under this subpart by following the applicable method specified in § 98.33(c). (b) Calculate and report biogenic CO 2 emissions under this subpart by following the applicable methods specified in § 98.33(e). The CO 2 emissions (excluding biogenic CO 2 ) for units subject to this subpart that are reported under §§ 98.3(c)(4)(i) and (c)(4)(iii)(B) shall be calculated by subtracting the biogenic CO 2 mass emissions calculated according to § 98.33(e) from the cumulative annual CO 2 mass emissions from paragraph (a)(1) of this section. Separate calculation and reporting of biogenic CO 2 emissions is optional only for the 2010 reporting year pursuant to § 98.3(c)(12) and required every year thereafter. [75 FR 79155, Dec. 17, 2010]