[Pollster1]

There are about 342543511 cubic miles of water in the oceans (think of a cube 700 miles along each edge!). I’m impressed if we can change the pH enough to matter - considering that we have about 60,000,000,000 gallons per person.

[Flint]

This one is easy.

People swim in the ocean. When swimming they pee in the ocean. Make a law to stop peeing in the ocean. Problem solved!

[I got the rope]

The acidity would have to change at least a 100 times to start harming marine life.

BUT...think about this...higher levels of CO2 would mean that the CO2 would start to precipitate out as calcium carbonate...even higher levels would precipitate out as gypsum. If it were extremely high it would precipitate out as dolomite. Ocean acidification due to man-made CO2 is impossible.

[Aut Pax Aut Bellum]

There are about 342543511 cubic miles of water in the oceans (think of a cube 700 miles along each edge!). I’m impressed if we can change the pH enough to matter - considering that we have about 60,000,000,000 gallons per person.
Well, I did pee in my 60,000,000,000 gallons a couple of times last vacation, so that could explain why my share went up in PH...