Since noone mentioned it, i rather would.
Anything within the athmosphere which in some way blocks radiation - often works both ways. I.e., there is not only reduced amount of Sun's energy which reaches the surface (that is, if a given substance is not hugely transparent to all major sunlight's frequences), but also reduced amount of energy which ends up radiated back into space (that is, if same given substance is not hugely transparent to all major frequences radiated by Earth, most importantly IR bands).
Forest fires, for example, produce lots of black soot. Sure, that blocks much of sunlight. However, what you think will happen when IR photons from the surface of Arctic go up? Obviously, lots of them will be blocked by the same soot. And then that soot will re-radiate, probably also some IR, and much of that will go back down - instead of happily ending up in space and starting its journey to far reaches of our pretty Universe.
Calculating these balances is still well beyond the scope of truly detailed and precise 3d modelling of Earth's athmosphere, i believe. With all sorts of frequences, substances, densities of particulates (which change all the time in every direction), it's a nightmare for any modeller...
P.S. Oh, and we do have an excellent example of "there is lots and lots of things in the athmosphere" nearby - planet Venus. If it's of any indication, then we can massively oversimplify and generalize by stating this: when there is lots of dense and non-transparent things in the sthmosphere - surface temperature tends to be higher than otherwise it'd be. My personal assumption to the cause of this is rather simple: incoming radiation is more energetic than secondary radiation which the planet radiates back, and due to higher energy, incoming radiation penetrates "deeper" per photon per meter than secondary radiation, and therefore, average case is a photon which ended up deep enough into semi-transparent athmosphere than it's needed for another average photon to have average chances to be radiated back into space. It's sort of a trap. Then, of course, with constant income of more and more sunlight over time, the "extra bit" accumulates, being re-radiated in any random direction (including downrards). This explanation might be clumsy and hugely rudimentated, but i think it grasps the cause of Venus' very high surface temperature somewhat.