Among other things, Christopher James Huff wrote:

> But you can't continue to accumulate it indefinitely...for example, if
> the stored energy were never used, plants would eventually run out of
> CO2 and H20 to build the sugars which they store the energy in. You will
> eventually reach some equilibrium where total input == total output.
> However, if albedo includes radiation as well as reflection, then
> objects like suns and gas giants have albedos greater than 1.
> 
> Also, albedo could be used to refer specifically to visible light...in
> which case it would actually be possible for the reflective albedo to be
> greater than 100%, due to fluorescent materials on the surface.
> Extremely unlikely on a dead rock, though a planet with a large amount
> of fluorescent plant life could do it naturally.

I albedo refers only to reflection, it cannot be higher than 1 and it can be 
certainly lower. The emr (electromagnetic radiation) absorbed and then 
emitted (possibly at a different wavelength) by the body is not reflection, 
it's (heat, black-body) radiation, fluorescence, or whatever.

If albedo refers to all kinds of emissions, it can be higher than 1. The 
Earth was probably born as a giant molten rock ball, now it has a more or 
less solid crust, some energy has been lost and radiated to outer space. 
The albedo can also be lower than 1 if the received energy is transformed 
to a different kind of energy and accumulated in the body itself.

If we are talking about a closed system (no exchange of matter) and in 
equilibrium (something not trivial), then yes, as much energy as it is 
received must be released. But energy is not only emr.

-- 
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