Jan 'splite' K.

And I'm not a scientist, but I think 75 years is not enough. CO2 is not going to disappear by itself, it has a lifespan of 1000 years, so you would need ~13 jumps to get rid of todays CO2. And first jumps will be probably really messy - the climate is so messed up right now that acid rain clouds are (probably) protecting us from warming. If you shut everything down, temperature will goes up, not down. At least initially..

If you took the power source of this device and reuse it, you could shut down all the dirty and probably most of the clean power sources we use today.

IANAL but this is silly... You just need Offer letter - I can create dummy ltd, write you offer for bambilion $ and dissolve the dummy ltd. You have your letter (which is just piece of paper bcs company no longer exists) and I will never pay you a single penny - you can sue but good luck, this ltd (which was legally responsible, not me.) no longer exists...

50 to 100 km is nothing in space (lets say, rounding error when triangulating position from visible stars will be muuuuuuuuuuuch bigger then negligible 100 km) Also, heat doesnt move nor exists well in vacuum (there isnt any material to bring the heat from one point to another), so 3000/5000 K hot sphere isnt really gonna work just like that...

I think great question would be other way around - what would fantasy army do after their first annihilation? Direct attack is out of the question now that they know they are against great magic ("Any sufficiently advanced technology is indistinguishable from magic." © ® ™ Arthur C. Clark.) and... What next? I think we are looking at the beginning of the hell of asymmetric warfare at much greater scale then Iraq (a much smaller expedition corps - you say ~300 soldiers - vs... whole word minus one faction?)

Not for full answer, so i leave just comment: Long time ago i read (fantasy ;) ) book about desert nation with so few resources that each person at 25th birthday make suicide and was bring back as... not zombie exactly, but something like zombie haunted by original soul. They had to consume magic, but not food and they was just "living" as happy as before. The book was about some "dark" necromancers who wanted to know how they can create so flawless undead (and the secret was that they did it voluntarily & no-one even try to control them). Whole nation was ok with necromancy.