Indirectly and to some degree, that heat IS involved, but much greater is the effect of Greenhouse Gasses (so the theory goes) that allow more SOLAR HEAT to collect and not get re-radiated into space, and I would have to include with that the great wastes and therefore overproduction in the power system that creates and transports that electricity; from basic inefficiencies and line-losses, to countless, mis-applied systems. We casually turn on the A/C to Cool a space that is simultaneously/constantly being heated by a Refrigerator, Lighting and other Electronics, and Solar Gain thru windows and leaky, uninsulated Walls and Roofs, while the ground, some 5 feet below the first floor is probably at a very acceptable temperature.  

  That statement might sound very pollyanna-istic (expiali-docious!).. but is easily proven with a few simple changes, some at each end of the Grid..