The First Two Laws for Climate and CO2
Written by Anthony Bright-Paul
If I drive my car to my local Supermarket and back, a distance of 5 miles, the engine gets hot. Why is that? Because of work done. To be more specific the engine has got hot by reason of compression, combustion and friction all of which are forms of work that produce an increase of temperature. This illustrates very simply the First Law of Thermodynamics.
If you were to put your hand on that hot engine – well, please don’t – it would also illustrate what is meant by thermal contact. Your hand would be scorched. As it is the air surrounding the engine is warmed.
If I leave my car to stand say overnight in my driveway, what will happen? The engine will cool down, without any work. I do not have to cool my engine because everything under the Sun will cool down naturally and inevitably by the 2nd Law of Thermodynamics. Even red-hot lava will cool to black basalt.
If I make a hot cup of coffee with boiling water at 100ºC the coffee will also cool by itself. If I wish to keep the coffee hot I can put it in a thermos flask. This will delay heat loss, but after 24 hours the coffee will be tepid. The coffee may be trapped, but heat is never trapped.
The Sun does not send heat through space but Solar Radiation. This radiation produces heat on contact with the surfaces of this planet, and the atmosphere is warmed from the bottom up – which explains why there is snow on the tops of mountains. The atmosphere cools by 2ºC for every 1,000 feet of altitude.
Clouds and Water Vapour, Carbon Dioxide and Methane all conspire to keep the Planet cool during the day, and also warmer during the night, by delaying (not trapping) heat. Thick cloud, fog and mist clearly intercept the Sun’s rays in the daytime. Only when the Sun breaks through is there a sudden rise in temperature.
Carbon Dioxide is a clear colourless gas, whose bubbles one can see in every carbonated drink – not to be confused with smoke. Carbon Dioxide is a food for plants – it is their breakfast, lunch and dinner. More Carbon Dioxide will lead to a greener world and increased food production. Plants not only feed off Carbon Dioxide in the atmosphere but all produce Oxygen for us humans and all the animal kingdom to breathe.
Author of ‘Climate for the Layman’