(Not wanting this tread to become a GW tread, but still..)
The heat dissipates into space just like the other 99.9% or so of the energy from the sun.
Heat produced by humans have just local effects, the heat will soon radiate away.
Have you ever noticed that a night with clear skies is colder than one where there are clouds? That is because the clouds work like insulation and traps the heat.
(On a cloudy day it's the opposite)
Every day the earth receives enormous quantities of heat from the sun, if not almost all of it went back into space, the earth would be boiling.
The question about global warming is weather a little more insulation is added to the earth or not. It's not about human-produced heat.
Nature intended things that burn to be burnt. A cloud also introduces a libido (white reflectivity) that repels solar heat during the day. Global warming (night and day) is about unnaturally added excess-heat from our (soullessly bestial destructive-anthropogenic) destructive perversions of nature here. (like the destructive and eternally toxic waste-byproducts of pointless thermonuclear-communist Bohemian Grove terrorism)
If fail to see how anyone could excuse a thousand new honorless-war-communist-made "suns" on the surface of our world as anything "natural".