Assume that someone made a 400,000+ km long rope and managed to attach it to the Moon. The rope is strong, but not unrealistically strong (carbon nanotube?). Now, Earth and Moon have kinetic and potential energy.Hhow would you use the rope to collect this energy for human use, up to the point when the Moon will be very close and the Earth will tidal lock to it? And how much power and total energy it would theoretically be possible to harvest in such way? What would be the most noticeable short-term and long-term effects on Earth? Would the Earth get tidally locked to the Moon much before the Moon comes really close (about the geostationary orbit) to the Earth?
Edit: as suggested in one of the comments, the rope should be really strong and light in order not to break just because of its own weight. Any conventional material would probably break, though there are indications CTNs (carbon nanotubes) might be fit for the job ( https://en.wikipedia.org/wiki/Space_elevator ). However, unlike a Space Elevator here the rope would not necessarily stand vertical to the earth surface. If the rope is instead kept horizontal (for example keeping its end around a point on Earth where the Moon appears at the horizon), would then the stress on the rope's material be significantly less than the Space Elevator case?