Question

The tropospheric lapse rate (the rate at which temperature decreases with altitude) is approximately 6°C per kilometer. Given that the mean surface temperature of Earth is 288 K and the effective radiating temperature is 255K, from what altitude does most of the emitted radiation derive?
drwls
33 C/(6 C/km) = 5.5 km above the earth's surface is where the atmospheric temp is 255 K.