1. A method for environmental management of a vehicle having a window, at least one sensor for sensing a respective environmental condition of the vehicle, and a heating, ventilating and air conditioning (HVAC) system including an HVAC control system operable to perform a plurality of functions, including controlling operation of: a fan system for generating an airflow, an air conditioning system for cooling the airflow, a recirculation system for controlling the amount of fresh and recirculated air introduced into the HVAC system, a mode system for controlling the direction of the airflow, and a heating system for heating the airflow, at least some of the functions being automatically controllable to effect defogging of the window, at least some of the automatically controllable functions being subject to manual overrides by a vehicle occupant, the method comprising: determining certain environmental conditions for the vehicle; determining when it is desirable to defog the window based on the determined environmental conditions; determining a status of the manual overrides; and implementing at least some of the automatically controllable functions of the HVAC system to effect defogging of the window when it is determined that none of the manual overrides has been selected.