With passenger numbers growing and time to slash emissions dwindling fast, the industry must tackle urgent stumbling blocks on fuel, frequent flyers and more

Aviation tanked in 2020. The number of people taking flights fell by three quarters compared with 2019 levels and as a result there was a significant drop in greenhouse gas emissions from aviation. But as countries open up and people begin to fly again, aviation is expected to see a slow climb back to previous levels. The industry anticipates a return to 2019 passenger numbers globally by 2023 and to be back on track with previous growth projections within a couple of decades.

All this is bad news for the planet. CO₂ emissions from the industry are likely to triple by 2050. But if the world is to limit global heating to 1.5C, it needs to have hit net zero CO₂ emissions by this time. Aviation is a complicated sector to decarbonise. It has some prickly ingredients: difficult technological solutions, hidden extra climate effects, an association with personal freedoms and a disproportionately wealthy and powerful customer base. Here are just a few of the big hurdles the sector will need to overcome if it is ever to be carbon neutral.