It's tin foil hat time, but I honestly believe that if the fossil fuel companies we're so powerful and didn't have a vested interest in it not happening, we'd easily come up with a way to supply the world with energy in this way and from other renewable sources.
This is about as close to a balanced argument as I can see on this thread.
We're not in a one thing or the other situation here. Whatever we've put into the atmosphere in the last 100 years HAS made a difference (especially on the polar ice) and we need to stop doing it, there can be no doubt...