Two questions for the greenhouse pundits.



The earth is not a greenhouse. Science does not dispute this. A greenhouse gets hot by allowing the sun’s ray through glass. These rays are absorbed by the solid matter within the greenhouse causing the matter within the greenhouse to warm up. The energy comes into the greenhouse as radiation, becomes heat upon absorption and causes the greenhouse to be held at a higher temperature than the air outside as the walls and roof of the greenhouse trap the heat in. Just the same as a car heats up inside if left sitting in the sun.

Science is allowing its self a few liberties in this area with the presumption that the earth must emit as much radiation as what it receives. This presumption was first made in 1824 by Jean Fourier but can it be true. Sure you can find wonderful animations and diagrams all over the web about it but instincts about a star versus a planet says they are barking up the wrong tree.

This presumption is at the heart of why the earth is being allowed to be considered to be something akin to a greenhouse. As a layman, when you first read about the presumption, you could be forgiven for saying “What? Could a square metre of the earth emit as much radiation as a square metre of the sun?” Well as two square metres of the earth as the sun only shines on half the earth.

Instinct says such is just not possible and it would be delightful to find some scientific reckoning somewhere that explains how such could be true. These are the energy ranges of each. Infra red 2 x 10-22 to 3 x 10-19 joule. Ultra violet 5 x 10-19 to 2 x 10-17 joule. If infra red was in its upper end 24 hours a day and ultraviolet was in its lower end all the time it might do it. But the upper end is the radiant emissions from stuff on fire so it doesn’t seem to be a possibility. The quantity of energy emitted increases with heat and much of the earth is pretty cold.

It is with that presumption that the term greenhouse continues to be applied. The four walls and roof of an actual greenhouse trapping heat within are interposed with water vapour and some other minor gases trapping the earth emissions (not heat as in an actual greenhouse) within the earth’s atmosphere.

This is the critical point where the sun emissions = the earth’s emissions seems to take us down the garden path. This presumption makes heat second fiddle. The sun’s emissions arriving on the earth causes the earth to heat. The way the presumption is structured is that the earth’s emissions cause the earth to cool. Don’t think anyone is going to argue that the earth’s emissions take the heat of the day away but we would probably be more with nature if we had a scientific determination on why the earth is unable to hold heat. Why does it get cold at night is the question.

So the two questions for greenhouse pundits are.

1/ Can the earth emit as much radiation as what it receives from the sun?

2/ Where does the heat of the day go to at night?

A no to one means the greenhouse theory is a red herring. A sound answer to two starts to put things into perspective.