Major US airlines and Amazon.com's aviation unit are joining an effort to speed the development and use of sustainable aviation fuels (SAF) to decrease emissions in air transport.

The Sustainable Aviation Buyers Alliance (Saba) said Amazon Air, Alaska Airlines, JetBlue, and United Airlines are joining the effort, which includes major corporate airline customers, to help drive greater SAF production, price cuts and technological advancements.

The Environmental Defense Fund and the Rocky Mountain...