398.2 ÷ (398.2 + 18.4 + 86.4) = 79% radiation

Notice on the energy graph, as pointed out by the folks at CFACT, that back radiation is stated as 340.3 w/m² onto the surface, while the sun's radiation is 163.3 w/m², as if the cold atmosphere could radiate more energy onto the Earth's surface than the sun can. That happens because of endless contradictions that can't be resolved when contriving absurdities.   Back to Stefan-Boltzmann Constant   Radiative Transfer Equations