Flights of fantasy

Aviation tanked in 2020. The number of people taking flights fell three-quarters compared with 2019 levels and, as a result, there was a significant drop in associated greenhouse gas emissions. But as countries open up and people begin to fly again, aviation is expected to see a slow return to previous levels. The industry expects 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 global heating. CO 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 emissions by this time. Aviation is a complicated sector to decarbonise. It has some prickly ingredients: difficult technological