Geoengineering ideas from the 20th century that (luckily) didn't make it

Ever since the God of the Old Testament granted our species dominion over the Earth

Injecting their religious beliefs into the article somewhat takes away from its message.

There was a plan to build a canal to the center of Australia since the desert there is below sea level. It would have turned Australia into a Laurel wreath of lush farmland.

Also the nazis wanted to dam the Mediterranean and pump the water out while also having it evaporate to make an African/European supercontinent.