Latent Heat and Trapped Heat
We have to be careful to distinguish between latent heat and trapped heat, particularly in the sense that Anthropogenic Global Warmers use the term.
Latent Heat is used most often, following Joseph Black, to describe the change of state from ice, a solid, to water, a liquid, to steam, a gas (water vapour), which are all chemically of the same composition.
In order to clarify the difference to ourselves we may buy at a Supermarket a bag of ice. Let us open the bag and pour the contents into a large saucepan, put it on the stove, light the gas. Having applied x calories of heat the ice rapidly turns to water – it has changed from a solid to a liquid, chemical composition H2O.
If I continue to heat this pan of water until 100C, the water will turn to steam, a gas.Steam and water vapour are one and the same, except that the concentration in the atmosphere differs. Steam is clearly visible to the naked eye, whereas water vapour istransparent, though it can be seen on summer mornings as dew rising from the grass.
It is notable that steam rapidly loses its heat and quickly condenses. This demonstrates the volatility of gases. Hot water on the other hand will retain its heat for a long period compared to the gas, demonstrating heat capacity.
Of course, steam can be used to drive turbines and steam engines – the beginning of railways and the industrial age. We can use a bag of ice in order to learn about the Arctic. If we keep the bag in a cold store where the temperature is rarely if ever above zero C. the ice will barely melt at all. However put the same bag of ice in a bowl of tepid water, the ice will melt rapidly. This shows that Arctic Ice will melt, not from the atmosphere, as the AGWs seem to think, but as the result of warm currents of water.
The AGWs use the analogy of sunlight on a stationary car, with windows closed. They aver correctly that the temperature within the car will rise, and they call this ‘trapped heat’. What they omit to add is that this rise of temperature will only occur and continue while heat is being generated. Once the Sun goes down the heat rapidly disperses.
This demonstrates that all sensible heat has to be generated, that such heat is never trapped, but is either being generated or being dissipated. There is no steady state. In particular, there is no way that Carbon Dioxide can trap heat – such an idea is bizarre!
Here I hope I have demonstrated the difference between latent heat and sensible heat in a way that is comprehensible to the layman.
Anthony Bright-Paul
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