Could a partial answer to the power question be a large-scale bike system merging the power from people pedaling (probably some hydraulics in there) to drive a generator?
It seems that people could burn a few calories and generate substantial kilowattage with a bit of clever engineering.
Same concept applied to an Archimedes pump bringing seawater to the top of a gravity-driven reverse-osmosis purification plant could increase arable land.
It seems that people could burn a few calories and generate substantial kilowattage with a bit of clever engineering.
Same concept applied to an Archimedes pump bringing seawater to the top of a gravity-driven reverse-osmosis purification plant could increase arable land.