1. The temperature at which motionless saturated air would induce, in a sedentary worker wearing ordinary indoor clothing, the same sensation of comfort as that induced by the actual conditions of temperature, humidity, and air movement. Effective temperature is used as a guide in air-conditioning practice, and, on the comfort chart (American Society of Heating and Air Conditioning Engineers), it appears as a family of curves that serves as one coordinate in defining comfort zones. Compare sensible temperature, cooling temperature, operative temperature. 2. In phenology, the temperature at which plants, especially cereals, begin to grow; generally about 0°C (32°F), for example, winter wheat, to 7°–10°C (45°–50°F), for example, maize. See degree-day. 3. With respect to radiation, the blackbody temperature that would yield the same amount of radiation as that emitted. The effective temperature of the earth as a whole is about 254 K, corresponding to an average emittance of 236 W m−2.