For high voltage distribution they are very efficient and change relatively little about the ecosystem. Moving the same power through the earth is not only more

For high voltage distribution they are very efficient and change relatively little about the ecosystem. Moving the same power through the earth is not only more expensive (counter-intuitively, buried power cables must have thicker conductors to carry the increased reactive loading due to the cable itself; and you obviously need insulation; and digging trenches is more expensive than erecting a steel tower every few hundred meters or so), but puts quite a lot of heat into the ground, apart from a lot of digging. [1] (There are actively managed buried cables which are oil or gas filled, but this becomes impractical for longer cables, or extensive networks. It's extremely expensive as well. This technology is mostly used in the catacombs underneath cities, to get 380 or 220 kV to power stations inside [or underneath] cities). Low or medium voltage distribution is a different story and has been buried in most of central Europe for many decades. I don't recall seeing power lines in any city. [1] Just to avoid someone from posting it inevitably: No, HVDC does not solve this.