It is starting to happen now. Many ocean current turnovers rates are at or approaching the time since the start of the industrial revolution. Up until a few dec

It is starting to happen now. Many ocean current turnovers rates are at or approaching the time since the start of the industrial revolution. Up until a few decades ago we kept getting clean water coming up from below with low concentrations of CO2. Now we are getting CO2 laden water that can't absorb nearly as much and what "fresh" water we got left coming to us isn't going to last much longer.