Will everyone here with an advanced degree in, and a career studying, climate science please raise their hands? All I hear are the same old quasi-political arguments rehashed in an aviation forum.
This is not a zero-sum game: If engineers could get funding to develop a Star Trek transporter, how would that be any skin off your cyranos? The development of flying machines was anything but a straight line and enormously dependent on unanticipated scientific discoveries and technical breakthroughs. And wars.
The last environmentally-friendly fuel that humans used for transportation was hay, but those engines were 'way too heavy to get off the ground. But their exhaust was good for the Earth.
As for future aircraft energy sources, I’ve never heard so many creatures arguing in favor of continuing to use their own fossilized remains.