"Well, put lots of living things everywhere. To explain exactly what happened to cause the apocalypse - there are centers, hearts of - damn, you don't have the word for it, uh, essence? Of the world. You can drain the hearts of essence to power all sorts of magical things. Just taking a little bit is fine, they regenerate on their own. Taking more than that is ill-advised, but not in itself world ending. The problem is when you figure out a way to move the essence hearts, and then put them all in one location so you can easily recharge all of your magic things. Because then, you have places that don't have any essence hearts at all, and that will kill everything, because new hearts will try to form to replace them. But they won't have any essence, and will steal it from living things to reform. So that happened.

"In order to fix that, I need to feed them essence so that the new - nodes, nodes are a better term than essence hearts, so that the new nodes have essence again. There are a few ways to do that, but the method I'm favoring is growing lots of plants with a lot of essence to steal from, because even fixing the nodes wouldn't restore the climate, and I might as well do both at once."