Home Discussion Forum How much energy is emitted by the Sun, and how much is...

# How much energy is emitted by the Sun, and how much is emitted by the Earth?

okay call me stupid but I can not find the answer to this anywhere it is either not explicitly stated or not known or eluded too or is just referred to as 6000 K (kelvin) for the Sun and 300 K for Earth…
Also how would I figure it out the energy Earth emits if it were say 30â€œC…

1. At any given time the Sun is emitting 400 trillion trillion watts of energy. In one second, the Sun produces enough energy to power our entire modern civilization’s needs for half a million years.

2. http://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)
3.34Ãƒâ€”10^31 J =the total energy output of the Sun each day
1.5Ãƒâ€”10^22 J = the total energy from the Sun that strikes the face of the Earth each day
now with global warming, the earth is not radiating all of the energy it receives.
so the earth is emitting, probably, more than 1.49Ãƒâ€”10^22 J each day.
if the earth did not do that, it would heat up fairly rapidly.
it is heating, but not rapidly, on a day-to-day basis.
note that, if you know the energy that the sun is radiating, and you know the size of the earth, and it’s distance from the sun, it’s not a terribly difficult calculation. On the other hand, if they’re going to just hand me the answer, i’ll use it.

3. The total energy emitted is equal to Surface Area*flux per m^2.
As Surface Area = 4 pi R^2 and flux = sigma * T^4 (Stefan’s law for black bodies) the answer is
L= 4 pi R^2 sigma T^4.
For the Sun T = 5,780 K and for the Earth T= 288 K.

4

6

7

3

6