Aviation has a problem: it's reliant on fossil fuels which release greenhouse gases when they're burned in a jet engine. Other industries are worse polluters, but in the next few decades, they are likely to decarbonise much faster than the airline sector.

Why? Because kerosene is a light enough fuel for planes to get off the ground, while producing enough thrust for them to do so. Also it enables airliners to carry passengers to the other side of the world.

International flight has only been around for less than 100 years, but research suggests that it's responsible for 4% of total global warming to date. It's not just that airliners pump out carbon dioxide, but they also emit nitrous oxides and soot. Even contrails, which are mostly water vapour, have a warming effect high up in the atmosphere.

Can efficiencies in jet engines, optimal routes and air traffic control lead to less fuel being used? What technologies are available to make flying cleaner? Is the pace of change fast enough to meet net zero by 2050?

Presenter: Ben Ansell

Contributors:

Rethink is a BBC co-production with the Open University