They're both in the wrong though. Magma wants to get rid of the ocean, and pretty much wiping out most water Pokémon in the process and a huge water source for humans once we actively use technology to de-toxify sea water. Aqua wants to get rid of the land, thus wiping out many terrestrial Pokémon in the process.

Either way, they're both contradicting their own goals. So I'd actively try to stop both.