A paper published today in Atmospheric Chemistry and Physics finds that clouds located in the stratosphere over the poles act to cool the stratosphere by adiabatic cooling, which is the cooling of air parcels as they rise and expand, rather than by ‘trapping heat’ below the clouds resulting in ‘radiative cooling’ of the stratosphere above.
This finding contradicts a tenet of AGW theory, which predicts that infrared radiation from greenhouse gases will ‘trap heat’ to create a ‘hot spot’ in the troposphere and cooling of the stratosphere. This study finds that cooling of the stratosphere is instead due to rising air parcels rather than a decrease in radiation due to heat ‘trapped by greenhouse gases’.
Gravity is a far more potent force than radiative cooling.
The Gas Laws dictate that as a gas (e.g. air) is heated at constant pressure, it expands, reducing the density. [This makes hot air balloons work.]
Gravity (Archimedes’ Principle) dictates that a body (a warm ‘air mass’) becomes bouyant when immersed in a larger mass of fluid (the atmosphere).
If the bouyancy exceeds the weight of the body, it will float. [This makes updrafts.]
Gravity also dictates that the pressure of a compressible fluid will decrease with altitude.
Thermodynamics dictates that when a gas is allowed to expand adiabatically (by reducing the pressure that confines it with no chance for it to exchange heat with its surroundings), it will cool down.