Carbon can exist in the atmosphere as carbon dioxide (CO2), methane, (CH4), or as a lot of bigger organic molecules like ethane. Over years, methane you release will eventually decay into CO2. But until that happens, the methane has 20 times the greenhouse effect that CO2 does. So processes like this can take CO2 from the air and turn it into methane, which is bad.

We need less flying, but if we’re going to have flying, it should use technologies like this which have 1/10th the lifecycle emissions of fossil jet fuel.