We get ~240watts per square meter and radiate at 290 kelvin where does the extra come from?

Question

A blackbody radiating 240w/m^2 cannot be at a temperature of 290 kelvin and yet the greenhouse therory says it does.

Answer 1

The Earth radiates 240 W m–2, which is equivalent to a surface with a temperature of around –19°C (254 K).  Greenhouse gases in the atmosphere absorb and re-radiate  much of this energy, which warms the surface to roughly 14°C (287 K).