Special relativity has to do with the consequences of the speed of light being independent of the motion of an observer relative to a light source.  General relativity is Einstein's theory of gravity.  There is a nice thought experiment where you imagine being in an accelerating elevator.  A light ray passing by appears to curve due to the acceleration of the observer in the elevator.  But the observer cannot tell the difference between being in an accelerating elevator and at rest in a gravitational field.  Therefore, a light ray will also bend in a gravitational field.  Of course, this is all completely irrelevant to climate.