The actual temperature of Earth's surface is an average 288 K (15 °C) as of 2020. The difference between the two values is called the greenhouse effect. The greenhouse effect results from materials in the atmosphere (greenhouse gases and clouds) absorbing thermal radiation and reducing emissions to space, i.e., reducing the planet's emissivity of thermal radiation from its surface into space. Substituting the surface temperature into the equation and solving for ε gives an effective emissivity of about 0.61 for a 288 K Earth. Furthermore, these values calculate an outgoing thermal radiation flux of 238 W m (with ε=0.61 as viewed from space) versus a surface thermal radiation flux of 390 W m (with ε≈1 at the surface). Both fluxes are near the confidence ranges reported by the IPCC.