United Airlines is the first U.S. airline to publicly commit to reducing its own greenhouse gas emissions by 50 percent by 2050, relative to 2005. It is the equivalent of removing 4.5 million vehicles from the road each year, or the total number of cars in Los Angeles and New York City combined.

“At United, we believe there is no point in setting challenging and ambitious goals without also taking tangible steps toward achieving them, especially when it comes to securing the health of our communities and our planet,” said Oscar Munoz, CEO, United. “While we’re proud to be [the] first U.S. carrier taking such an ambitious step, it is a distinction we look forward to sharing as the rest of the industry catches up and makes similar commitments to sustainability.”

To celebrate, United operated Flight 44 from its San Francisco (SFO) hub to Zürich (ZRH) with its most fuel-efficient aircraft, the Boeing 787, via a blend of sustainable aviation fuel. The airline used 16,000 gallons of biofuel at a 30/70 blend with conventional jet fuel. It is the longest trans-Atlantic flight to date powered with biofuel volume of such a size.

United is the first airline globally to use sustainable aviation biofuel on an ongoing daily basis and invested more than $30 million in sustainable aviation fuels producer Fulcrum BioEnergy.