Iswearihaveajob is correct - that card will protect you from the Greek Fire.
Note however that it only protects you from ONE boost card. So if you had already used to to protect yourself from say, Particle Beam, or Electromagnet, it would offer no extra defense.
Actually the Faraday Cage allows you to ignore multiple opponents' boost cards the round you play it: "if you played this card immediately after an opponent played a boost card, you may ignore it. Also, ignore any further Boost cards you choose for the rest of the round."
So yes you can ignore the extra track damage from Greek Fire by playing Faraday Cage before or in response to it.