Does Superman need to breathe?
No. Superman flies in space for fun when he first discovers he can fly. Superman flies through space in order to rescue Lois from her damaged escape pod. Superman takes a round trip up to the orbiting Wayne Enterprises satellite and back. Less overt feats include walking through the burning oil rig without breathing apparatus, remaining underwater during an entire flashback sequence, traveling at extraordinary speed which would rip the air from one’s lungs, and routine feats of super-human strength as discussed in MOSAIC Episode 4. Whether or not you accept these later examples, the first three are undeniable proof that Superman does not have to be within (and breathing) Earth atmosphere to have his strength and powers.
This is both the typical Superman tradition and a logical application of our understanding of what respiration does for us. Simply put, we breathe oxygen in order to biochemically “burn” our food stores for energy. Therefore, it is logical that Superman bypasses the need for oxygen because he primarily metabolizes sunlight, rather than food, and that his feats would consume more energy than food stores could ever provide.
Why do some think he needs Earth’s atmosphere to be strong?
They are likely drawing a few faulty conclusions. First, that Jor-El’s atmosphere line pertained to Superman’s powers. Second, that Jor-El changing the atmospherics on the ship was giving Superman back the source of his strength, rather than understanding that the main point was to take away the Kryptonian atmosphere that was suppressing Superman’s strength (he adapted it to Earth merely to kill two birds with one stone and allow Lois to breathe freely if her helmet was to be compromised). Addressing each in turn: read more
