The Earths Energy Balance
I will now introduce a popular diagram showing the Earth’s Energy Budget .
You can see the 342 W/m2 incoming solar radiation in the top-centre of the picture.
We will now look at he next points in the CSIRO’s explanation.
“Sunlight passes through the atmosphere, warming the earth’s surface.”
This point is further expanded in another CSIRO information booklet  as follows:-
“The atmosphere (including its GHGs) is largely transparent to the Sun’s energy, most of which arrives in the form of light.”
This is a bit misleading. The implication is that Sunlight passes through the atmosphere un-impeded. This is obviously not true.
Of the 342 units of Sunlight reaching the Earth, 77 (or 22.5%) are reflected by the atmosphere – mainly by clouds. As well 67 units, or about 20%, are absorbed by the atmosphere (once again – mainly by clouds). This energy does not reach the surface of the Earth. 30 units or about 9% are reflected at the surface.
Of the original 342 units only 168 is available for “warming the earth’s surface.” The atmosphere is hardly “transparent to the Sun’s energy”.
In turn, the land and oceans release heat, or infrared radiation, into the atmosphere, thus balancing the incoming energy.
NO – once again this is misleading. The incoming 168 units of energy is balanced by outgoing convection and radiation. According to Kiehl and Trenberth’s model, 102 units of energy are released from the surface due to convection (air flow and latent heat), and 66 units by radiation. (This is obfuscated in the diagram – there is 350 + 40 upwards and 324 downwards = 66 upwards).
More heat is released from the surface of the Erath by convection then by radiation. this is important, why is it over looked?
Water vapour, carbon dioxide and some of the other trace gases absorb part of this radiation, allowing it to warm the lower atmosphere, while the remainder is emitted to space.
‘Part of this radiation’ that is ‘absorbed’ by GH gasses, means part of the 66 units radiated from the surface, (see above) not the 102 units of energy flow from the Earth by convection. This energy is not absorbed by these GH gasses.
It is not clear what is meant by “allowing it to warm the lower atmosphere”. There seems to be a common view that heat can flow from a cold atmosphere and warm the warmer surface of the Earth. This proposition defies the second law of thermodynamics. Surely scientists at our leading scientific bodies understand basic thermodynamics?
A consequence of the second law of thermodynamics is that heat flows from a hot body to a cold body. Heat exchange between two bodies will cause the hotter body to cool and the colder body to warm until some equilibrium is reached. It is that simple; there is no known observation of heat flow causing cold bodies to increase the temperature of a hot body. This is a fundamental law.
Why then do we have this climate model where it is proposed that heat flowing from the cold atmosphere somehow raises the temperature of the warmer Earths surface. I have seen and read many wonderful explanations of how this happens. Usually it is something like the following:
“…the greenhouse gases in the atmosphere absorb some of the outgoing terrestrial (infrared) radiation and re-radiate infrared energy in all directions. There is thus now more radiant energy (short wave plus long wave) being absorbed by the ground and so it heats up further, by some tens of degrees, until the upward infrared emission just balances the total downward infrared and solar radiation…” (BOM Publication, The Greenhouse Effect and Climate Change)
This reasoning shows a misunderstanding of heat flow and energy flow. It is probably easier to understand if we were to consider heat flow by convection.
Have you ever stood in front of an air-conditioner on a hot day. The surface of the air conditioner is cold. Air is forced over the surface and is blown toward you, cooling your face. Now, in this process the cold surface of the air conditioner warms, your warm face cools. Heat flow is from your face to the air-conditioner. But air flow is in the opposite direction. The air obviously has quite a bit of internal and kinetic energy. Air flows from cold to hot but the hot surface cools and the cold surface warms. The effective heat flow is in the opposite direction.
Lets look at an illustration from the Energy Budget diagram above. In the lower centre of the diagram are the arrows indicating heat flow by convection or air flow (Thermals and evapo-transpiration). But as everyone knows this mass flow is not just upwards. Rain and hail is one example of mas flow, and therefore energy flow, downwards. Does hail warm the surface of the Earth? No! Does hail have energy? Yes! So why doesn’t this energy increase the temperature of the Earth?
Unlike convection it is harder to comprehend exactly what radiation is. Can we picture radiation energy as photons, little balls of energy like miniature hail-stones? Or is it a wave like waves on the oceans or in a slinky spring like we used in high-school? All these ideas are just models to help us picture and maybe predict the behaviour of radiation. Whatever the model there is no reason to assume that it will not obey the second law of thermodynamics. “Cold” photons may flow downwards but heat will flow from hot to cold.
The statement “There is thus now more radiant energy (short wave plus long wave) being absorbed by the ground and so it heats up further” is fundamentally and demonstrably wrong.
Why is this flawed argument used by our ‘leading’ scientific bodies?
Are these the arguments that have convinced government to spend billions to curb “climate change”?
Next, I will look at what controls the temperature of the Earth
1. CSIRO Marine and Atmospheric Research, “The greenhouse effect Information Sheet” accessed at http://www.cmar.csiro.au/e-print/open/holper_2001b.html
2. CSIRO publication “Climate And Greenhouse Gases, By Michael Raupach and Paul Fraser” accessed at http://www.publish.csiro.au/?act=view_file&file_id=CSIRO_CC_Chapter%202.pdf
4. Kiehl, J. T. and Trenberth, K. E., 1997 Bull. Amer. Meteor. Soc., 78, 197-208.
5. BOM Publication, The Greenhouse Effect and Climate Change, http://www.bom.gov.au/info/GreenhouseEffectAndClimateChange.pdf