wat da hell for
they dont explain it until a different set of comics. The Quiver story arc.
taken from wiki:
The character appears in Frank Miller's Batman: The Dark Knight Returns and the sequel Batman: The Dark Knight Strikes Again. Despite missing an arm (implied to be because of Superman), Oliver still proves to be an effective archer (he grasps the nocks of his arrows in his teeth).
The Emerald Archer later acquires a cybernetic replacement for his lost arm from Batman in the sequel. The death scene in Green Arrow #100–101 pays tribute to Miller's story. Superman's only course of action to rescue Green Arrow is by removing his arm, but Queen refuses to let him--admitting later in Quiver that he refused due to both his own issues at this point in his life and the more practical issue that he would be useless as an archer with one arm--thus bringing about his apparent death.
In The Dark Knight Returns, Queen is portrayed as an anarchist, while in The Dark Knight Strikes Again he is explicitly described as a "billionaire turned Communist."
Cant wait for Arrow to return this week on CW