http://cn.arxiv.org/ftp/arxiv/papers/0811/0811.0357.pdf The Pseudo Radiation Energy Amplifier (PREA) and the mean earth’s ground temperature Ahmed Boucenna Laboratoire DAC, Département de Physique Faculté des Sciences, Université Ferhat Abbas, 19 000 Sétif, Algeria ………………………………………………………………... From the radiation balance diagram1 illustrating the IPCC reports2 one can estimate the power received by Earth from the sun at Pin = 342 W/m2 and the power consumed, remitted and reflected by the earth and its atmosphere at Pout = 599 kW/m2. It seems that the earth emits more power than it receives. The earth’s ground mean temperature is estimated at 15 °C. A calculation based on the black body radiation theory gives an earth’s ground mean temperature of the order of -18 °C which is much lower than 15 °C. The important gap between these calculated and estimated temperature mean values requires an explanation. Here we show that a gray body separated from vacuum by an interface and submitted to outside incident radiation can behave like a Pseudo Radiation Energy Amplifier. The Earth which is a gray body separated from the space by an interface, behaves like a Pseudo Radiation Energy Amplifier. The balance of the energy exchanged between Earth and outer space is reconsidered and the 15 °C Earth’s ground temperature mean value is then derived. Our result revives the discussion on the parameters that control the Earth climate. The solar and terrestrial radiation reflection coefficients by the earth and its atmosphere acquire a privileged role. The Pseudo Radiation Energy Amplifier can be a starting point to improve the energy use. The materials having the adequate reflection coefficients will be indicated for specific applications.-----------------------------, I am not sure i understand this.