The boss of the world's second biggest airline has said that tackling climate change will make flying more expensive.
"Over time, it's going to cost us all more, but it's the right approach that we must take," Delta Air Lines chief executive Ed Bastian told the BBC.
Aviation is responsible for about 2.5% of the carbon emissions that are warming the planet, according to the International Energy Agency.
Critics argue the best way to reduce them is by flying less. Atlanta-based Delta says that after spending $30m (£22.4m) a year on carbon-offsetting it has been carbon neutral since March 2020. It has also pledged to spend $1bn over the next decade to cancel out all the emissions it creates.
More fuel-efficient planes, sustainable aviation fuels and removing carbon from the atmosphere are some of the ways it hopes to achieve this.
Reducing carbon emissions is crucial if the world is to limit global warming to 1.5C above pre-industrial levels as agreed in Paris in 2015.