Pope Benedict said on Monday that saving humanity from homosexual or transsexual behavior was just as important as saving the rainforest from destruction.
"(The Church) should also protect man from the destruction of himself. A sort of ecology of man is needed," the pontiff said in a holiday address to the Curia, the Vatican's central administration.
"The tropical forests do deserve our protection. But man, as a creature, does not deserve any less."
The Catholic Church teaches that while homosexuality is not sinful, homosexual acts are. It opposes gay marriage and, in October, a leading Vatican official called homosexuality "a deviation, an irregularity, a wound."