Non-CO₂ is the immediate climate lever (hours to days)

The Future of Flight Chemistry

Aviation climate impact isn’t just CO₂. Contrails, soot (nvPM), and sulfur oxides (SOx) dominate near-term forcing, turning fuel chemistry into a first-order lever for compliance and atmospheric protection.

The “2/3 Rule” Non-CO₂ effects represent roughly two-thirds of aviation’s net climate impact in the framing used by this primer.
CO₂
centuries
Long persistence. Necessary to solve, but slow to deliver near-term cooling.
Non-CO₂
hours → days
Short-lived effects provide “climate leverage” that can be adjusted immediately.
MRV
mandatory
NEATS operationalizes chemistry into auditable reporting and financial exposure.

Evidence Pack

TERC (Sheffield) — tLCAF nvPM & Emissions

Third-party ground test outputs (fuel properties + measured emissions) packaged for airline and verifier review. This is intended to provide inputs for evaluation; it does not represent outcome guarantees.

Evidence Pack | Positioning Guardrails

1) The Invisible Impact: Beyond the Visible Exhaust

Radiative forcing Contrails nvPM SOx

Contrail cirrus

High-altitude ice clouds formed when water vapor condenses on soot particles, trapping outgoing longwave radiation (especially at night).

Particulate matter (nvPM)

Non-volatile soot particles that act as the primary “seeds” for ice crystal formation in the upper atmosphere.

Sulfur oxides (SOx)

Fuel-borne sulfur produces SOx and sulfate aerosols, influencing cloud formation and atmospheric chemistry.

Visual: share of impact (illustrative)

This chart mirrors the primer’s framing: non-CO₂ ≈ 2/3; CO₂ ≈ 1/3.

Why executives should care

Non-CO₂ controls short-term forcing and becomes a near-term compliance and reputational lever. This shifts strategy from “fuel volume” to “fuel chemistry + atmospheric interaction per flight.”

Time advantage Unlike CO₂, contrail mitigation can change warming outcomes immediately (hours/days after flights).

2) Regulatory Phase Shift: From Voluntary to Mandatory

Regulation (EU) 2024/2493 MRV NEATS Defaults

What NEATS does

NEATS is an IT-based tool designed to automate tracking of non-CO₂ impacts per flight and enable MRV reporting.

Default-values penalty

If an operator cannot provide required fuel property data (e.g., aromatics or sulfur), the regulator applies “worst-case” defaults—raising reported liability.

Compliance timeline

Jan 1, 2025 — Monitoring mandate begins
Start

Operators are legally required to monitor non-CO₂ effects; the “voluntary era” ends.

Mar 31, 2026 — First verified reporting deadline
Verified

Verified reports on soot, aromatics, and sulfur content are submitted to regulators.

Punitive defaults (worst-case assumptions)

Defaults applied when data is missing Aromatics 25% (vol) Sulfur 0.3% (mass)
Provide monitored primary fuel data to override defaults and reduce reported exposure.

Defaults Override Simulator (qualitative)

Select a tier to evaluate default exposure.

Choose reporting tier

Level 1: defaults assumed. Level 2: provide monitored fuel properties to override defaults. Level 3: highest fidelity (data intensive).
Optional strategic indicator; shown as directional only (not computed here).

Fuel chemistry inputs (optional)

Default: 25.0
Default: 0.300
This is a qualitative illustration of “defaults penalty” vs “primary-data override.” It does not compute legal CO₂e.

3) The “SAF Gap” and the Technical Blend Wall

Scarcity Cost multipliers ASTM D7566

Supply scarcity

Global production remains a fraction of demand; the primer cites UK provisional 2025 supply reaching only ~1.6% of mandated target.

Economic unfeasibility

Bio-SAF (HEFA) pricing at ~3–5× fossil Jet A-1; synthetic e-SAF at ~13×.

The “blend wall”

Under ASTM D7566, most SAF is capped at 50% blend to maintain seal integrity—leaving a large fossil fraction and soot precursors in the tank.

Why the blend wall matters for contrails If half the tank remains high-aromatic fossil, soot precursors persist—capping contrail-forming reductions.

4) Engineering the Solution: The Chemistry of tLCAF

Lubricity paradox ASTM D1655 Drop-in

The lubricity paradox (why this is hard)

Deep removal of sulfur/aromatics can improve emissions, but can destroy natural lubricity. The primer frames tLCAF as using a pure hydrocarbon improver to restore lubricity while staying Jet A-1 compliant.

Headline outcomes

Ultra-low sulfur and low aromatics aim to cut SOx and soot precursors. The goal is a fully compliant, 100% drop-in fuel without a blend cap.

Metric Conventional Jet A-1 tLCAF (DM-XTech) Strategic effect
Sulfur content 3,000 ppm (limit) < 10 ppm (≈99.7% reduction) SOx near elimination; improved short-term forcing profile.
Aromatic content ~18% to 25% (avg) ~8.5% Fewer soot precursors → lower nvPM → contrail mitigation potential.
Blend limit N/A No limit (100% drop-in) Bypasses ASTM D7566 blend cap dynamics for operational scale.
Compliance-friendly posture Primary fuel property data (aromatics, sulfur, etc.) can override default penalties in MRV reporting.

5) Empirical Evidence: TERC Emissions Analysis

Honeywell 131-9A APU nvPM number nvPM mass Parity

nvPM reductions (reported ranges)

Full load: particle number −40% to −50% and mass −30% to −40%. Ready-to-load/idle: particle number −55% and mass −80%.

Local ESG benefit Idle/ground nvPM mass reduction is positioned as valuable for airport air quality narratives.

Visual: midpoint reductions (illustrative)

Midpoints used for visualization only: FL number 45%, FL mass 35%, idle number 55%, idle mass 80%.

NOx

Equivalent to Jet A-1 (no increase) in the primer’s summary table.

CO₂

Equivalent to Jet A-1 (no increase) under the same test framing.

THC

Marginally lower (cleaner burn) in the primer’s table.

6) Atmospheric Protection: Contrail Mitigation as a Climate Lever

Soot-to-ice Short-term leverage Contrails

The “Soot-to-Ice” pipeline

Soot particles emitted into cold, humid air become nuclei for ice crystals; contrails spread into warming cirrus clouds. Lower soot precursors reduce nuclei density—thinning or shortening contrails in marginal conditions.

Fuel aromatics
→
nvPM soot particles
→
Ice nucleation
→
Contrail cirrus

Why it’s strategically potent

Contrail mitigation changes warming outcomes immediately, while CO₂ reduction has long persistence. This makes chemistry-based mitigation a near-term lever for results under pressure.

Immediate cooling effect Reducing soot today can reduce radiative forcing in the hours and days after flights—an actionable near-term lever.

7) Summary: tLCAF as Compliance Infrastructure

Scale now Bypass blend wall Defaults override

Immediate scale

Deployable via existing infrastructure, without requiring new aircraft or supply chains.

Scalability

Bypasses feedstock scarcity and blend wall constraints that limit SAF-led near-term mitigation.

Effectiveness

Targets contrails and SOx and is positioned to eliminate worst-case default reporting penalties under MRV logic.

Operational next step (practical) Create a “primary data pack” (aromatics, sulfur, and other monitored properties) so MRV reporting consistently overrides defaults.
Caveats & positioning guardrails
tLCAF / zLCAF are positioned as drop-in Jet A-1 with a QA + traceability evidence pack. Any MRV interpretation remains airline-controlled and verifier-led.
External caveats Approved vs forbidden claims