Aviation is responsible for around 2.5% of the carbon emissions that are warming the planet, according to the International Energy Agency.
Delta, which claims to have been carbon neutral since March 2020 after spending £22.4 million a year on carbon offsetting schemes, pledged to spend a further $1 billion over the next decade to "cancel out" all emissions it creates.
Andreas Schafer, professor of energy and transport at University College London, reportedly said it will "cost trillions rather than billions of dollars" to move the global aviation sector to net-zero carbon emissions.
