Climate Change

It is appropriate to look a bit deeper into the evaporation process itself. The Aral Sea was a large water body and it had large sea-going vessels plowing its waters. As such, the sea had a huge amount of water in it. If we assume that it contained 1.5 billion litres of water prior to the accelerated evaporation, and 1 billion liters were evaporated. We can calculate the amount of energy that was required to covert liquid water to vapour. In physics, it is know that approximately 1200 calories of heat energy is required to convert 1 litre of liquid water to vapour. So in the case of the Aral Sea water reduction, 1.2 trillion calories of heat energy were required to convert the 1 billion litres of sea water to vapour. That amount of energy was stored in the vapour as latent energy, and given that vapour can travel in any of the three possible dimensions, i.e., upward, north, east, south and west, that huge energy reservoir could have been transported to any part of the globe where it would be expended when the vapour is converted back to liquid in a rainfall. In the event of the vapour being converted to snow, the amount of heat energy expended would even be larger than the 1200 calories per litre. If you consider that large bodies of water such as the Dead Sea, Lake Mead, Lake Victoria, Lake Chad and many others have had large net losses of water leading to drops in the levels of those water bodies, it is clear that the dynamics of heat transfer to the atmosphere have been stupendous over the past two decades. Liquid water requires heat energy to power the transformation from liquid to vapour. The absorbed heat energy is transferred to cooler vapour molecules when rain is formed from vapour. In the case of the Aral Sea example, 1.2 trillion calories of energy were absorbed at the lake site to create vapour. But this vapour travelled thousands of kilometers from Aral and as it was hovering at a place far away, in Alaska for example, it released the latent heat in order to be transformed to snow or rain. More heat would have been released if the transformation was from vapour to snow than it would have been if the transformation was from vapour to rain.