The aviation sector's Carbon Offsetting and Reduction Scheme for International Aviation is not facing a dearth of verified emissions reductions, but a shortage of governments willing to authorize the credits they already hold and a delay in climate finance to host countries that have signed letters of authorization or LOAs, panelists said Wednesday at a World Bank conference.

"The current supply bottleneck (in eligible credits) is primarily driven by host country authorization and capacity building requirements around the authorization process," said Helen Finney, Head of Carbon Market at the U.K. Department for Energy Security and Net Zero. "It is not actually an underlying lack of underlying mitigation activities."

Kelvin Lee, Head of Sustainability Asia Pacific at the International Air Transport Association noted that failure to achieve broad Phase 1 compliance would trigger fragmentation, with regional schemes and individual countries moving to fill the gap left by a collapsed global mechanism.

"Either Corsia survives Phase 1 and moves on to Phase 2, or it does not. It's zero or 100," said Lee at Innovate4Climate, the World Bank's annual conference held in Singapore.

The Forest Carbon Partnership Facility and the BioCarbon Fund Initiative for Sustainable Forest Landscapes -- two agriculture, forestry and land-use standards managed by the World Bank across approximately 19 to 20 host country programs -- could both supply between a quarter to one third of Corsia Phase 1 demand, assuming a total Phase 1 requirement in the 150 million to 200 million metric tons range.