---
kind: "section"
citation: "40 C.F.R. § 98.43"
title: "40"
number: "98.43"
heading: "Calculating GHG emissions."
url: "https://uscodex.org/cfr/40/98.43"
---

# §98.43. Calculating GHG emissions.

- (a) Except as provided in [paragraph (b)](#b) of this section, continue to monitor and report CO2 mass emissions as required under [§ 75.13](/cfr/40/75.13.md) or [section 2.3](/cfr/40/2.3.md) of appendix G to [40 CFR part 75](/cfr/40/part75.md), and [§ 75.64](/cfr/40/75.64.md). Calculate CO2, CH4, and N2O emissions as follows:
  - (1) Convert the cumulative annual CO2 mass emissions reported in the fourth quarter electronic data report required under [§ 75.64](/cfr/40/75.64.md) from units of short tons to metric tons. To convert tons to metric tons, divide by 1.1023.
  - (2) Calculate and report annual CH4 and N2O mass emissions under this subpart by following the applicable method specified in [§ 98.33(c)](/cfr/40/98.33.md?p=c).
- (b) Calculate and report biogenic CO2 emissions under this subpart by following the applicable methods specified in [§ 98.33(e)](/cfr/40/98.33.md?p=e). The CO2 emissions (excluding biogenic CO2) for units subject to this subpart that are reported under §§ [98.3(c)(4)(i)](/cfr/40/98.3.md?p=c-4-i) and [(c)(4)(iii)(B)](/cfr/40/98.3.md?p=c-4-iii-B) shall be calculated by subtracting the biogenic CO2 mass emissions calculated according to [§ 98.33(e)](/cfr/40/98.33.md?p=e) from the cumulative annual CO2 mass emissions from [paragraph (a)(1)](#a-1) of this section. Separate calculation and reporting of biogenic CO2 emissions is optional only for the 2010 reporting year pursuant to [§ 98.3(c)(12)](/cfr/40/98.3.md?p=c-12) and required every year thereafter.

## Notes

### Amendments

[75 FR 79155, Dec. 17, 2010]

### Authority

Authority: 42 U.S.C. 7401-7671q.

### Source

Source: 74 FR 56374, Oct. 30, 2009, unless otherwise noted.

### Amendments

[75 FR 79155, Dec. 17, 2010]