I just read an article about another city in California ramping up their desalination of sea water to supplant their city's water needs. This is in response to a drought in CA since the desalinated water cost 30% more so they don't do this casually. But how does desalination in general affect atmospheric water vapor a marginal factor in atmospheric heat retention (think clouds)?
All else equal salt water boils at 103' C*** vs 100'C for fresh water so fresh water evaporates more easily. That may only be a small marginal effect, but I suspect the far larger issue is surface area exposed for evaporation. The sea surface area is relatively constant for this discussion, while any extra water removed from the ocean and used for agriculture, or washing cars and watering lawns will marginally increase water in the local atmosphere.
Rainfall tends to average out, so drought here means more rainfall somewhere else. While a warmer atmosphere can hold more water (just like summer humidity vs winter). Adding desalinated water to compensate for local drought increases total water in the atmosphere.
It seems rainfall will automatically prevent the atmosphere from holding too much water locally while there are probably large regions of the atmosphere well below saturation and holding less water.
While I don't know that california cities are altering the atmospheric balance, I wonder about major desalination programs to support agriculture in former dessert areas like in the middle east.
I am not making any claims one way or the other just throwing out some armchair science to chew one. Increasing clean water resources using desalination is clearly a man made phenomenon. I don't know if it's good or bad, but like so much, everything can have unintended consequences.
JR
*** the actual boiling temp for sea water depends on how much salt it is holding in solution. The ocean around the equator is more salty than the ocean in polar regions.
All else equal salt water boils at 103' C*** vs 100'C for fresh water so fresh water evaporates more easily. That may only be a small marginal effect, but I suspect the far larger issue is surface area exposed for evaporation. The sea surface area is relatively constant for this discussion, while any extra water removed from the ocean and used for agriculture, or washing cars and watering lawns will marginally increase water in the local atmosphere.
Rainfall tends to average out, so drought here means more rainfall somewhere else. While a warmer atmosphere can hold more water (just like summer humidity vs winter). Adding desalinated water to compensate for local drought increases total water in the atmosphere.
It seems rainfall will automatically prevent the atmosphere from holding too much water locally while there are probably large regions of the atmosphere well below saturation and holding less water.
While I don't know that california cities are altering the atmospheric balance, I wonder about major desalination programs to support agriculture in former dessert areas like in the middle east.
I am not making any claims one way or the other just throwing out some armchair science to chew one. Increasing clean water resources using desalination is clearly a man made phenomenon. I don't know if it's good or bad, but like so much, everything can have unintended consequences.
JR
*** the actual boiling temp for sea water depends on how much salt it is holding in solution. The ocean around the equator is more salty than the ocean in polar regions.
