Aer Lingus and British Airways owner International Airlines Group has committed to powering 10% of its flights with sustainable aviation fuel by 2030.
The move comes as it seeks to make progress towards its longer term goal of achieving net zero carbon emissions by 2050.
The group's pledge comes on the same day as a US-led climate change summit hosted by US President Joe Biden, aimed at securing commitments from governments on cutting carbon emissions.
IAG said today it plans to purchase one million tonnes of sustainable jet fuel each year by 2030, which is said will be the equivalent of removing one million cars from Europe's roads each year.
The sustainable fuel generally produces up to 70% less carbon than fossil fuels.
This offers airlines a way to become greener while continuing to fly, before less carbon-intensive hybrid, electric or hydrogen aeroplane options become available from the late 2030s.
IAG, an Anglo-Spanish company, is headquartered in Britain, which has one of the world's most ambitious climate change targets. The UK is aiming to cut carbon emissions by 78% by 2035.
Due to the Covid-19 pandemic, flying is currently at very low levels, but at the same time, pressure is growing on carriers to cut emissions.
"It's clearly challenging to transition to a low carbon business model but, despite the current pandemic, we remain resolute in our climate commitments," IAG chief executive Luis Gallego said in a statement.
Airlines hope that by reducing their carbon footprints, they can win back passengers who, due to Covid-19, have realised they do not need to fly as much.
Gallego said that government support would be critical to helping attract investment to get sustainable aviation fuel plants up and running and producing sufficient volumes for the future.
IAG plans to invest $400m in developing sustainable aviation fuel over the next 20 years, including building a household waste to sustainable jet fuel plant in the UK.
