We present an adiabatic model of the earth's atmosphere that describes the thermal behavior observed under the greenhouse effect. The adiabatic regime assumes an average distribution of thermodynamic variables in the atmosphere, which depend only on altitude. Non radiative thermal contributions are included by adjusting the adiabatic coefficient, such that the thermal lapse rate coincides with the measured value in the tropics, equal to 6.5 K/km. Global warming is derived from an energetic radiation balance of the incoming solar radiation, and radiations from the earth's ground and troposphere. We assume the increase of CO2 concentration in the atmosphere in the industrial era, as the main cause of global warming. Using the concept of radiative forcing, we derived expressions for the tropospheric emissivity as a function of CO2 concentration. Moreover, we established a simple expression to describe the lapse rate behavior with increasing CO2 concentration in the troposphere. Finally, we discuss some experimental techniques for the detection of global warming in the next decades.
adiabatic atmosphere; greenhouse effect; climatic evolution; global warming
