Lets ignore the temperature and climate debate, stuff involving ice sheets that constantly melt and refreeze and so on.
Are you doubting the numbers about how the ocean is more acidic than it used to be? I ask for the acidity is something that does not fluctuate on a daily basis like climate does. There are many ways to make the oceans more acidic but a higher amount of CO2 in water as (Hydro) Carbonic Acid is one such way of increasing the acidity.