Beer's Law

taunuu = e-sec(theta) integ kappanu rho dz
kappanu = sumkappanu(CO2,CO,CH4,N2O) + kappanu(H2O) + kappanu(O3)

Transmittance between the top of the atmosphere and level at z is a function of the quantity and absorption of all gases.

The taller the glass, the darker the brew,
The less the amount of light that comes through.