Tinfoil would stop the heat from the sun getting IN. The glass keeps the air heated by the sunrays from getting out.
We have special glass in our house, a so called K-Glass. It lets the heat easier in than out.
A manufacture with applied physics, acting on the knowledge on how greenhouse effect works.
So, in my example, tinfoil cover would work like dimming (components from volcanoes like i.e. sulphur do that, the effect being that the sunrays do not reach the surface to heat) while darker surface (such as sea vs ice) will trap the heating effect, and then certain components (such as the effect of my living room window, C02, Methane etc) will bounce the heat back in.
I do not understand your "feelings" about the whole deal as any other than a hot-headed denial. Mine are different, - some concern about the whole business, with growing scepticism on the deniers, since their forts seem to be falling one by the other like Hortlund so promply put it.