Science Deniers and the "isothermal atmosphere" (Now it's getting silly #2)

The Alarmists don’t usually have the guts to say it out loud, but there is a sub-school of psuedo-scientists among them who seem to believe that in the absence of Greenhouse Gases, the atmosphere would be the same temperature all the way up. That’s the problem with flawed theories, you have to keep adding new theories to explain the previous contradictions until it gets laughable.

This is complete insanity; we know that there must be a lapse rate, either from direct experience or reliable evidence from others:

1. Space is empty and “cold”. There is nothing there to store thermal energy, so it is either close to absolute zero, or simply has no measurable temperature at all. So the top layer of the atmosphere that merges into space is also very cold.

2. Sunshine warms the surface of a planet. This warms the air above it by simple conduction and convection.

3. The atmosphere gets thinner (both pressure and density fall, but not at the same rate) as you go up. So it’s thickest at sea level and thinnest where it merges into space.

4. On the basis of this, it would be reasonable – and correct – to assume that the temperature also falls as you go up, as mountaineers and aviators will testify. If a hypothetical atmosphere were isothermal, what temperature would it be? As cold as space or as warm as the surface? The pseudo-scientists never commit one way or another.

5. Clever scientists also tell us that the thicker the atmosphere, the warmer a planet is at the centre. It gets warmer as you go down, even if not much (and effectively no) sunlight ever gets to the centre. Gas giants (Jupiter, Saturn) have atmospheres that are tens of thousands of kilometres thick and as far as we know, their cores are tens of thousands of degrees hot. That’s how stars form, a cloud of (initially cold) hydrogen has enough gravity to compress the gas in the centre to a very high temperature and pressure, sufficient to trigger nuclear fusion (which also gives off thermal energy, but that is a separate phenomenon).

6. Sure, some of gas giants’ core heat is created by a distant relative of nuclear fusion (I can’t remember the name for this effect and don’t claim to understand it anyway), but we notice it even on Venus, whose hard surface gets very little sunshine, but its atmosphere is a hundred times thicker than Earth’s and its surface is very hot. I am quite sure, on the basis of all this, that atmospheric thickness is as important in determining hard surface temperature as is incoming sunlight, even though that is a bit counter-intuitive (how else would stars form? There’s no sunlight to kick-start them.)

7. Any other assumptions are madness. This temperature gradient is stable; the lapse rate is largely because of the trade-off between thermal energy (at the surface) and potential or gravitational energy higher up. And the ratio between temperature, pressure and density is such that it complies with the Gas Laws all the way up. An atmosphere will not and cannot ever become isothermal.

What brings on this rant/recap of things I have explained many times before?

I followed a link from the recent article I covered about hurricanes. The interviewee makes some good points, but being an Alarmist, they let slip that their underlying assumption is that without GHG’s, the atmosphere would be isothermal. They must know that this is bollocks and do not actually commit to saying that air would be absolute zero, although this is implied:

… we would not have hurricanes were it not for the greenhouse effect, by the way.

But the earth has this nice blanket of gasses around it. And some of those gasses are very important greenhouse gasses, water vapor being the most important, and also carbon dioxide, methane. And those gasses absorb some of the heat coming back up from the planet, and then re-radiate it back down to the surface.

Are we to believe that ‘pure’ air, with no water vapour or CO2 would not be warmed up by a warm surface? That there is no such thing as conduction and convection? Surely this would be easy to test in a lab? And air absorbs, stores or ‘traps’ thermal energy, it’s an insulator – that’s how warm clothing or double-glazing work. There is far more thermal energy in the atmosphere that there is in the top layer of the soil/rocks or ocean surface (those bits that warm by day and cool by night).

And as it happens, the ‘effective surface’ of the Earth or Venus is just like the Moon – it emits just as much radiation to space as it receives from the Sun. When you calculate ‘effective temperature’, you are working on the basis of ‘what the planet looks like from space’, so only the ‘effective surface’, what you see from space is relevant. Which in the case of Venus is just clouds, and in the case of Earth is two-thirds clouds and one-third exposed oceans or land. What happens between clouds and the surface between them is a separate, closed system.