Moving Beyond Carbon: Advancing Aviation Contrail Accounting and Reporting

RMI piloted three methodologies for accounting for aviation contrails in corporate travel, finding that a 'bottom-up' flight-specific approach is significantly more accurate than standard static multipliers. The pilots revealed that roughly 2% of flights cause 80% of contrail impacts, with higher risks during winter and nighttime. The report advocates for data-driven travel policies and alignment with emerging regulations, such as the EU's MRV framework, to reduce the total climate impact of aviation.

• RMI, in collaboration with Boston Consulting Group (BCG), Roland Berger, and Estuaire, piloted three methodologies for corporate contrail accounting: a Baseline Approach using a static 1.7x multiplier on CO2, a Differentiated Default Approach using tiered multipliers based on flight characteristics, and a Bottom-Up Approach using flight-specific modeling.
• The bottom-up accounting method provides significantly higher accuracy for CO2, contrails, and other non-CO2 effects compared to standard methods. Pilot results using this approach showed non-CO2 effects averaging a 1.3x to 1.32x impact, which is lower than the baseline 1.7x multiplier.
• Contrail climate impacts are highly concentrated; the pilot analysis revealed that approximately 2% to 2.14% of flight bookings are responsible for 80% of the total contrail impact.
• Contrail impact is non-linear and varies by season and time of day, with higher mean impacts observed during winter, cool spring, and fall months, as well as during evening and nighttime flights compared to morning departures.
• Current corporate reporting often relies on static multipliers that may misrepresent true climate impacts. The document suggests that companies can reduce emissions by using granular data to avoid routes and flight characteristics with high contrail-formation potential.
• The European Union's monitoring, reporting, and verification (MRV) framework, amended on September 23, 2024, requires airlines operating within the European Economic Area (EEA) to monitor and report non-CO2 emissions from each flight annually through 2026.

APA

RMI (2025). Moving Beyond Carbon: Advancing Aviation Contrail Accounting and Reporting. https://rmi.org/resources/moving-beyond-carbon-advancing-aviation-contrail-accounting-and-reporting/

Chicago

RMI. Moving Beyond Carbon: Advancing Aviation Contrail Accounting and Reporting. 2025. https://rmi.org/resources/moving-beyond-carbon-advancing-aviation-contrail-accounting-and-reporting/.

Wikipedia

{{cite report |author=RMI |title=Moving Beyond Carbon: Advancing Aviation Contrail Accounting and Reporting |date=8 December 2025 |url=https://rmi.org/resources/moving-beyond-carbon-advancing-aviation-contrail-accounting-and-reporting/ |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{rmi2025moving, author = {{RMI}}, title = {{Moving Beyond Carbon: Advancing Aviation Contrail Accounting and Reporting}}, institution = {RMI}, year = {2025}, month = dec, url = {https://rmi.org/resources/moving-beyond-carbon-advancing-aviation-contrail-accounting-and-reporting/}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }