; or (B) have entered into a binding, exclusive agreement with the operator to capture and dispose of in secure geological storage a specified quantity of greenhouse gas emissions. (3) Amount of offset credit For purposes of subsection (b)(2)(B)(iii), the total amount of the offset credit for any year shall be equal to the percentage obtained by dividing— (A) the quantity of certificates described in paragraph (1) surrendered to the Administrator by the operator during the previous calendar year; by (B) the total net lifecycle greenhouse gas emissions for the fuel or mix of fuels consumed by all of the flights operated by the operator in the previous calendar year as regularly scheduled flights subject to part 121 of title 14, Code of Federal Regulations (or successor regulations). (4) Limitation (A) Calendar years 2025 through 2049 The quantity determined under paragraph (3) may not exceed— (i) for calendar year 2025, the percentage determined under paragraph (3) shall not exceed 50 percent; and (ii) for each of calendar years 2026 through 2049, the percentage determined under paragraph (3) shall not exceed a maximum percentage that is 2 percentage points lower than the maximum percentage for the previous calendar year. (B) Calendar year 2050 and thereafter Beginning in calendar year 2050, and in each calendar year thereafter, no certificates under this subsection may be surrendered to the Administrator for purposes of determining the amount of the adjustment under subsection (b)(2)(B)(iii). (5) Expiration of certificates A certificate issued by the Administrator under this subsection shall expire 1 year after the date of issuance. (6) Additionality By not later than January 1, 2024, the Administrator shall promulgate regulations to ensure that any certificates issued under this subsection are for greenhouse gas emissions that— (A) are captured directly from the ambient air and disposed of in secure geological storage