How does CO2 affect sleep?

Andrew Huberman explained that during sleep, a specific issue arises related to the buildup of a CO2 cloud around your face. This occurs because, unlike during the day when your exhalation has more force and disperses the CO2, at night your exhalation is much gentler. Thus, CO2 tends to accumulate around your face, and when this exhaled gas is rebreathed, it can lead to disturbances in sleep. This problem is significant enough that it has long been studied in astronauts but is only recently being translated into applications for improving sleep in non-astronaut populations 1.