Under the new deal, airlines will be expected to offset their emissions growth after 2020 by buying “offset credits” in line with their carbon footprint.

The carbon costs are expected to incentivise the industry to develop lower-carbon fuels and technologies, while the money raised by the credits will fund environmental initiatives to help to tackle climate change.

This cost is forecast to grow to as high as $23.9 billion by 2035, or 1.8 per cent of the airlines’ revenue. At the same time airlines will need to spend more on developing lower emissions aircraft, technologies and fuel.

Still, there are many who believe that the cost is too low. UN observers at the campaign group Transport and Environment claim the costs are “peanuts” to the airlines and will amount “to little more than adding the price of a cup of coffee to a ticket”.