"Thinking about aviation fuels you get all the very clever people saying we use biofuels.
Then you speak to people who've done the numbers, for one major carrier to operate half of its domestic fleet on biofuels you must plant the whole of Victoria with palm trees for palm. It’s a staggering amount, so biofuels are not the solution, even though they might be part of it.
And then you get people saying, OK, we need synthetic aviation fuel. Combine molecules with clean hydrogen and make methanol and derivatives, this again, is a possible pathway.
It's a real stretch goal and it may be that we give up and we always accept that long distance aviation will be running on kerosene, and we must do offsets by sequestration.
But if we can solve it at source, of course, that's much better than doing the offsets. Globally pre-pandemic aviation itself is growing 4 or 5%, and as the rest of the easiest sectors to deal with for the economy are decarbonized, aviation would just come a bigger and bigger percentage of what remains."