I don't imagine it's "Aether" power being disrupted.

Uldah at least uses cerulium for all of it's lighting and burning purposes, that's what those large machines in Bluefog are for they are Cerulium harvesters. Gridanians use a different type of oil (Not mentioned) but refuse to use Ceruliem becuase it is "Devoid of elementals" where all other items in the world have elementals within them that will speak with the Conjurers.

This may be a hint that Cerulium is from a time before elementals existed, or some other strange susbstance that doesn't belong in Eorzea. As far as I can tell though it's the modern world equivelant to oil.