The 2025 Aviation Sustainability Lexicon is here
A guide to 50+ key terms shaping the future of flight.
Back in 2023, we released our first sustainable aviation dictionary—a guide to 35 essential terms that helped make sense of aviation’s climate conversation. It was a time when SAF was still gaining traction, “book and claim” felt niche, and the Paris Agreement’s 1.5°C target hadn’t yet been breached.
Fast forward to 2025, and the stakes—and the language—have changed. So has our lexicon.
Our updated edition includes over 50 entries that reflect how the conversation has evolved—from deepening regulatory frameworks to emerging technologies and market mechanisms that didn’t even exist a few years ago.
What’s new in this edition
We’ve added more of the essentials: clearer explanations of carbon insetting, CO₂ removal, and why things like “additionality” and “permanence” matter in real climate action.
The SAF section is stronger, with a simple breakdown of how fuels are made, what counts as sustainable, and why certifications like RSB, ISCC, and GREET matter.
New terms help unpack the infrastructure behind climate claims — from energy certificates to SAF registries — so you don’t get lost in the jargon.
You’ll also find updated entries on greenhushing, frequent flyer taxes, and flight shaming, as public expectations and scrutiny grow.
Whether you work in the industry, follow climate policy, or simply want to understand the changes happening in the skies above, this resource is here to support that understanding.