[Teknoman117]

What's the justification to expect that 25-50% of human climate impact will be from aviation by 2050?

Growing population? Lower cost of access to flight? Other industries decarbonizing and causing aviation impact to just be a larger fraction of overall impact?

[jabl]

IIRC it's a combination of air travel continuing to expand at the roughly 2.5% yearly rate it has been doing for the past decades, and other sectors of the economy successfully decarbonizing.