Merchants of Doubt had Hansen again repeat his nonsensical assertion that the high temperatures on Venus are due to the greenhouse effect. This is mindless mythological nonsense started by Sagan and constantly repeated by clueless climate scientists
Venus surface goes for months at a time without receiving any sunlight (due to very slow rotation on its axis) yet the temperature does not drop more than a few degrees. How can a “greenhouse” operate without any sunlight? The whole point of a greenhouse gas is that it allows SW solar radiation to pass, but blocks LW radiation.
Equally as damning is that the dry lapse rate on Earth is similar to Venus, and that it is unaffected by humidity.
When a mass of air is lifted, it cools at the dry adiabatic lapse rate of 5 1/2°F per 1,000 feet as long as it remains unsaturated (relative humidity below 100 percent).
Air at 99% humidity has ~99 times as much greenhouse gas as air at 1% humidity, yet the lapse rate is the same. It obviously has nothing to do with the greenhouse effect. The temperature at the surface is primarily controlled by the height of the troposphere. Temperature and volume are the only two degrees of freedom in the Ideal gas law. PV = nRT
Atmospheric pressure is fixed by the weight of the atmosphere . That doesn’t change. Similarly, n is fixed. R is a constant. The only degrees of freedom are V (determined by height of the troposphere) and T.
During the winter, the height of the troposphere decreases and temperature drops. During summer, the height of the troposphere increases and the temperature increases. If n increased (say due to volcanic activity) then P and V would also increase and T would rise proportional to the increase in number of molecules.
Venus is hot because it has a very tall, high pressure troposphere. If Earth didn’t have oceans and limestone, it would be extremely hot here for the same reason.
As long as the height of the troposphere remains relatively fixed, the temperature on Earth won’t change tremendously. If the Sun suddenly went out, the troposphere would collapse and so would temperatures.