Shu and Tefnut's Clique: Environmental Awareness Club (EAC)
There are quite a few nature gods. This group, led by Shu and Tefnut and their friends among the Greek Titans, seeks to make sure the earth (whether as Geb or Gaia) is taken care of.
Mannanan Mac Lir
This Irish god is the big man on the ocean, as well as lands beyond the ocean. (The otherworld needs a clean environment, too!) He's also known for a decent green thumb, with all the apples from the Islands of the Blessed to choose from.
Artemis
When the EAC raises enough money to make pro-environment commercials, they've already decided that Artemis will be their official spokeswoman. Not only is she a drop-dead-gorgeous Grecian hottie, she's Lady of the Beasts. All the animals and forests love Artemis, and can't wait to star alongside her.
Demeter and Persephone
Demeter's dedicated her immortality among the Greek gods to making sure the world stays green and beautiful. That is, of course, until her daughter, Persephone, takes off with her husband Hades to the underworld for a couple of months each year. Even though Demeter knows where she's going after, oh, several thousand years of this….she still throws a tantrum and refuses to let anything grow until little Persie returns. Shu and Tefnut think this is a bit melodramatic, but as long as both of them show up for EAC meetings, it's cool.