The Journal

Four Routes to Lower Aviation Emissions, Ranked by Timescale

Aviation decarbonisation is usually discussed one technology at a time, which makes it hard to see how they relate. Put side by side, they sort into a clear…

Why Kerosene Is So Hard to Replace

Kerosene has powered commercial aviation for seventy years, and it is worth understanding why nothing has displaced it — because the reasons are also the…

What Fuel Actually Costs an Airline

Fuel is one of an airline's largest costs and the one that moves most, which is why fuel price is discussed like weather in the industry.

Bigger Aircraft Are Not Always More Efficient

The intuition that bigger aircraft are more efficient per passenger is widespread and, on a fixed route, wrong often enough to be worth checking.

Hydrogen Is a Volume Problem, Not an Energy One

Hydrogen looks like the obvious answer to aviation: it carries nearly three times the energy of kerosene per kilogram and produces no carbon dioxide at all…

The Battery Gap: Why Electric Flight Is Short-Range

Batteries are not a little too heavy for aviation. They are off by more than an order of magnitude, and the gap is best seen by putting the same mass of…

Why a 2% SAF Blend Saves 1.4%

Blend mandates for sustainable aviation fuel are usually reported as a percentage, and the emissions saving is always smaller than that percentage.…

Why One Kilogram of Jet Fuel Makes Three of CO₂

Burn a kilogram of jet fuel and you get about 3.16 kilograms of carbon dioxide. The number surprises people because it is larger than the fuel — and the…

Electric Aircraft and the Battery Problem

Hydrogen Aircraft: The Case and the Catch

Jet Fuel: What It Is and Why Kerosene Won

Sustainable Aviation Fuel: What It Is and What It Replaces