No need to throw salt on desal wound

Letter writer Paul J. Trichilo need not worry that the oceans’ salinity will reach unacceptable levels due to either natural processes or human activities such as desalination plants (“Mailbag,” March 23).

First of all, according to theory it has taken about 3 billion years for the oceans to reach their present salinity, a little more than 3%. Presumably it would take another 3 billion years to double that, during which time plants and animals in the oceans would have time to adapt to the higher concentration through the normal process of evolution.

Evaporation of ocean waters is not a significant factor, since the water that is lost is essentially returned in the form of rain or runoff.

Finally, desalination plants do not add salt to the oceans, they only return the salt that was originally in the water. Thus any number of desalination plants would have no effect on the overall salinity of the oceans.

If anything, we are more likely to see a lowering of ocean salt concentrations due to the melting of our polar ice caps from global warming, something that is already being observed in the North Atlantic.