As Baute explains, there’s approximately 30,000 liters of air in the structure, which he estimates would typically sustain a human being for three days. But, as he points out, the carbon dioxide levels would build up to a lethal point long before that if the right plants weren’t around to counteract it. The 200 plants that are spread around Baute’s temporary shelter, reportedly including sunflowers, corns, and beans, were chosen specifically for that purpose.
Baute has equipped the space with environmental-measuring tools to ensure the oxygen and carbon dioxide levels stay at a healthy rate. Should the percentage of carbon dioxide in the air reach a dangerous level, he says he’s prepared to abort the mission.