In October 2021, at the 77th IATA Annual General Meeting in Boston, a resolution was passed by IATA member airlines committing them to achieving net-zero carbon emissions from their operations by 2050.

Exploratory work is ongoing to achieve flight without burning fossil fuel. It may be that net-zero flight is achieved by offsetting emissions. But it could also be that new technology allows for emissions-free flight, specifically, carrying passengers through the air without emitting any greenhouse gases. To disrupt fossil fuel flights this would have to be relatively affordable.

A useful benchmark for "affordable" is in relation to the median household income. Median US household income in 2021 was around $67,000, or $1280/week. At the time of writing this question, a one-way flight from New York to London could be purchased for around $350, or roughly 1/4 of one week's median household income. Allowing that technology might not quite become competitive with that level, this question asks whether zero-emissions flight could be achieved for less than 1/2 of one week's median household income in 2050. 1/2 of one week's median household income in 2021 is about $642.