Inert gas asphyxiation are more uncomfortable in low-oxygen environments that result from inert gas exposure; however, the experience is still less aversive than CO exposure. A typical human breathes between 12 and 20 times per minute at a rate primarily influenced by carbon dioxide concentration, and thus pH, in the blood. With each breath, a volume of about 0.6 litres is exchanged from an active lung volume (tidal volume + functional residual capacity) of about 3 litres. Normal Earth atmosphere is about 78% nitrogen, 21% oxygen, and 1% argon, carbon dioxide, and other gases. After just two or three breaths of nitrogen, the
Nu Earth Souther forces arrive to recapture the trenches. Nu Earth Nu-Earth is the name of a fictional planet near two suns and a wormhole that is the main setting for the Rogue Trooper fictional universe. Due to its strategic importance the Southers and the Norts are fighting over the planet. This perpetual war has seen the use of just about every weapon of mass destruction, which made the planet's atmosphere toxic. Most life forms became extinct or mutated, and all inhabitants must wear protective chem-suits at all times. Because of this the Souther scientists were instructed to start the G.I. program