Plug in an electric blanket. That's the sun. It radiates heat.
Now, lie on top of the electric blanket. You are the Earth. By lying in close proximity to the heat source, you become comfortable. You like your temperature.
Now, put a big down comforter on top of your body. This (the Left would say) represents Greenhouse gases. Suddenly, your temperature is increasing as more heat is retained. If you were comfortable 5 minutes ago, now you are uncomfortably warm.
The whole question is: Can humans put a blanket on the Earth? Do we produce CO2 is sufficient quantities so as to significantly cause the planet to retain heat better and therefore raise our base temperature a few degrees?
That's the whole question of AGW. And I still don't see where the Second Law of Thermodynamics fits in.
Well, yes, but it would have to be really, really big, and it would cost an awful lot.
Do we produce CO2 is sufficient quantities so as to significantly cause the planet to retain heat better and therefore raise our base temperature a few degrees?
CO2 doesn't help anything retain heat. Actually, it pretty much does the opposite.