Insulation works both ways, it keeps heat in and it keeps heat out. The mad scientists say co2 is keeping some sun heat in so it must also be keeping some sun heat out, so the global heat capacity must be in balance. But maybe the heat capacity is not in balance because at night there is no sun so there is a positive loss of heat which means the planet is cooling not heating. If it is heating up the extra heat maybe coming from some other cause like the earths molten core bleeding heat out.
