[dustinmoorenet]

That just seems odd to me to have a wire for earth... carried above the earth. I can understand having earth wires in houses made of concrete and wood since they have to get to the earth through those materials, but what makes a common earth ground better than just lots of many grounding points? All that wire has got to get expensive.

[ars]

See here: https://en.wikipedia.org/wiki/Single-wire_earth_return

[JoeAltmaier]

The earth is a pretty terrible conductor.

[dustinmoorenet]

The point of an earth ground is to dissipate the accumulation of static built up. Ground is not connected to the power supply so there is nothing to return to the power company. The earth is the best place for it.