Rigorous electromagnetic scattering solutions, based on the extinction theorem, are used to investigate the surface geometry contributions to the directional and hemispherical emissivity and to the directional hemispherical reflectivity for one-dimensional configured or random rough surfaces with different material properties. The surface parameters that affect the scattered energy are the surface geometrical shape, including the ratio of transverse length scale over wavelength r/A and height over wavelength a-/A, and the optical properties of the surface material. Through numerical calculations, the dominant contribution to these surface radiative properties is shown to be the slope of the surface, expressed by CT/T. For a surface consisting of multiple-length scales with different slopes, the subscale with a larger slope is shown to dominate the surface radiative properties of the surface.