I guess this could also work after you make separate fuel tanks for take-off and cruise.

The only drawback I see is the aesthetically unpleasant view of black smoke tails coming from the planes in the sky... not that it is that high of a price IMO, but I guess it would cause resistance.

I hope to analyze the prospects for direct injection of H2S into the stratosphere as a way to make cooling aerosols.  Haven't gotten there yet, and it would be a last-ditch effort anyway (hazardous to ozone).