For some years I have spent my time on exactly these questions - both in thinking about ways to prevent war, and in thinking about how to fight, survive, and terminate a war, should it occur.
A lot of people just go to movies that feed into their preexisting and not so noble needs and desires: They just go to action pictures, and things like that.
The places that are most likely to grow trees for carbon sequestration are places where trees aren't growing now.