Just spoils ecosystems which shouldn't be happening. Trains are the most greenest form of transport but we have to be aware of the ecological damage we do while building infrastructure. Even electrification is not green as most of electricity is produced by Coal. TN can make efforts to produce nuclear energy, it is very clean. India should take this up and there's mass production of power and it's almost 96% recyclable . Solar as well will become very bothering as there is not a lot of things we know about recycling solar panels.