International Civil Aviation Organization CAEP/13 CO2 standards

In February 2025, the International Civil Aviation Organization’s (ICAO) Committee on Aviation Environmental Protection (CAEP) agreed on an integrated dual-stringency with updated noise and CO2 certification standards for future aircraft development, called the CAEP/13 standards. This policy update provides an overview of the CAEP/13 CO₂ standard.

For new aircraft designs, also referred to as new type aircraft, the standard requires a 10% reduction in CO₂ metric value for the largest aircraft starting in 2032, measured against the CAEP/10 standard. For in-production aircraft types— new aircraft that have already been type certified—the standard requires up to a 6% reduction beginning in 2035 relative to the CAEP/10 standard. Compared to the current fleet’s performance, the standard requires future aircraft to have an average metric value reduction of 0% to 5%.

The ICCT conducted an impact analysis to assess the stringency of the new standards for new type and in-production aircraft. The analysis yielded the following results:

• Most new aircraft already comply with the CAEP/13 in-production limits, suggesting the standard will not drive further efficiency gains.
• The new standard provides limited incentives for additional technological innovation beyond existing market forces.

The ICAO Council and Assembly approved the recommended CAEP/13 CO₂ standard in June 2025 and October 2025, respectively. Member states will enforce it through domestic type-certification rules for new-type aircraft from 2032 and in-production aircraft from 2035, preventing non-compliant aircraft from operating internationally.

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