Abstract: In a method for detecting carbon dioxide in an enclosed volume, a CO2 detection system is triggered to awaken from a deep sleep state. Once awake, the system queries system sensors to determine the current system parameters, including current CO2 level and temperature. Current and expected CO2 decay rates are calculated, and the system determines whether the current CO2 decay rate is within an expected normal range for an unoccupied enclosed volume. If the volume is static, i.e., not moving, and the CO2 rate is rising and the temperature is rising, a series of alerts are sent to contacts previously set up by the user. If the alerts are not cleared by a user, emergency management personnel are notified.