The average temperature of the surface of the earth is approximately14◦c.

what would the steady-statetemperature of the earth be if there were no greenhouse effect — i. e. if the emissivity of the earth was independent ofwavelength?

give your answer in◦c.

note that the radius of the earth is6.38×106m, and the intensity of sunlightat the earth’s location is1366w/m2.

hint, how much power from the sun would strike a plate with the same radiusas the earth?

how does that power compare to the power that hits the earth?

another hint — i didn’t give you anemissivity. just all it, and if you remember that absorptivity and emissivity are the same, it will cancel out.