Global Warming Question: How does the Air get hot?

Written by Anthony Bright-Paul

Now here’s a problem all you Anthropogenic (man-made) Global Warmers can help me with, especially as I notice that at least one of you seems to know some Physics. How does the atmosphere get warm?

We are all agreed that 99% of the atmosphere is composed of Nitrogen and Oxygen, which leaves just 1% for the ‘Greenhouse Gases’, which includes Water Vapour and Carbon Dioxide at just 0.04% (or 400 parts per million, the human portion being just at most 0.000012%).  attenboroughNow the infrared radiation from the Sun encounters the mass of the Earth and heat is produced on the sands, rocks, oceans and lakes. So that is the picture. But the question is how does the air get hot?

The thing is – pardon my unlettered language – the thing is that Nitrogen and Oxygen are transparent to infrared radiation, near infrared and far infrared, that is oncoming and outgoing radiation. Of course, you guys have taught me that the ‘Greenhouse gases’ and in particular Carbon Dioxide is opaque to radiation, absorbs and emits it; -that is it emits radiation and thereby cools.

Apart from the fact that the molecules of Carbon Dioxide are only in proportion 1 to 250,000 that is not the real problem. It is the radiation.

You see and you must agree that the air does get hot or very warm indeed. Imagine standing in the middle of the Sahara with the sun beating down. The temperature of the sand gets to 70ºC and the air immediately above gets to 40ºC as happened in a most famous documentary with David Attenborough (pictured above).

So how does the air get hot? Can you guys help me out? If it can’t be radiation how does the heat transfer occur? Looking forward to your help.