As the aviation industry intensifies its climate accountability efforts, it’s becoming clear that carbon dioxide (CO₂) tells only part of the story. The non-CO₂ effects of aviation can contribute just as much—or more—to global warming. In response, regulators have established a structured framework for Monitoring, Reporting, and Verification (MRV) of these impacts.
This guide explains what non-CO₂ effects are, why they matter, and how aircraft operators can prepare to monitor and report them effectively.
What Are Non-CO₂ Aviation Effects?
When aircraft burn fuel at high altitudes, they release a range of emissions beyond CO₂. These include:
- Nitrogen Oxides (NOx): These increase ozone (O₃) and reduce methane (CH₄), both greenhouse gases.
- Water Vapour (H₂O): At high altitudes, this can form contrails that evolve into warming cirrus clouds.
- Non-Volatile Particulate Matter (nvPM): Includes soot particles that promote cloud formation and radiative forcing.
- Sulphur Oxides (SOx): Leads to sulphate aerosol formation, with complex climate interactions.
Together, these non-CO₂ effects significantly amplify aviation’s climate footprint, often doubling the total warming effect of a given flight.
Why Are These Effects Regulated?
The scientific community has highlighted the urgent need to include non-CO₂ effects in aviation climate policy. Although less direct than CO₂, these effects are immediate and potent contributors to global warming.
A structured MRV approach improves transparency, enables fair comparisons across airlines, and lays the groundwork for future market-based measures, incentives, and potential carbon pricing reforms.
Core Elements of the Non-CO₂ MRV Framework
Aircraft operators must track and report their non-CO₂ effects using standardised methods and models. Key elements include:
- Monitoring Plan: Must define methodology, data sources, and applicable routes.
- CO₂e Conversion: All effects must be translated into CO₂-equivalent (CO₂e) using Global Warming Potential (GWP) and efficacy weighting (EGWP).
- Models Used:
- CoCiP: Predicts contrail formation and evolution.
- aCCF: Assesses NOx and water vapour effects.
- OpenAirClim: Provides climatological estimates for small emitters.
Operators can use the EU’s official tool (NEATS) or approved third-party software that aligns with regulatory requirements.
Two Monitoring Methods: Method C vs. Method D
Operators must choose a monitoring methodology:
- Method C (Weather-Based): Uses actual flight data and meteorological inputs for higher accuracy. Default for large operators.
- Method D (Climatological): Simplified approach for small emitters using route- and altitude-based averages.
Each method affects the level of detail in reporting, tool requirements, and verification procedures.
Why This Matters for Airlines
Comprehensive MRV of non-CO₂ effects:
- Enhances climate credibility and ESG performance
- Reduces regulatory risk
- Strengthens stakeholder trust and market access
- Supports future eligibility for incentives or emissions trading benefits
How Vurdhaan Supports Non-CO₂ MRV Compliance
Vurdhaan is a leading advisory and technology partner for non-CO₂ MRV implementation. Our team brings deep expertise in aviation operations, emissions modeling, and regulatory strategy.
We help operators with:
- Monitoring Plan design and documentation
- Selection and configuration of Method C or D
- NEATS integration or third-party tool validation
- Emissions modeling and data enhancement
- Verification preparation and evidence pack creation
Whether you’re a large carrier or a small emitter, Vurdhaan ensures your non-CO₂ compliance framework is audit-ready, cost-efficient, and future-proof.
Want expert support for your non-CO₂ MRV strategy? Contact Vurdhaan to simplify your compliance journey and lead on climate accountability.