They might make sense if you have a very tall capital that is already boosted by a ton of trade routes (though there are few % modifiers, making the focus on a single supercity less desireable.). Peripheral cities would produce the gold necessary to make the capital awesome (and provide the TR's)
I just wish the AI was less spam-happy with them.
The link is broken - the ")" is outside the URL code.Oh, thats right it overwrites the base tiles yields:
http://civilization.wikia.com/wiki/Terrascape_(CivBE)
So really only going to be useful on low yield tiles.
Considering the only "low yield" base tiles are snow thanks to the Mass Digester and Vivarium boosting tundra and desert respectively, that energy cost makes a lot of sense. You're heating up hundreds of square miles of frozen wastes to have an open air tropical forest in the arctic circle after all!
But yeah, Terrascapes are something you build rarely and judiciously honestly, even with the +1/+1/+1 virtue for them. I just wish the AI was less spam-happy with them.
Of course you can get rid of them.