This graphic is from GRID-Arendal, a Norwegian Foundation collaborating with the UN Environment Programme. It shows CO2 concentrations in the ocean going up over a period of 20 eyars, and the corresponding drop in pH over the same time period.
Ocean acidification is a serious effect of climate change.

There are more climate change related graphics HERE.
Correction: "Ocean acidification AND CLIMATE CHANGE ARE a serious effect of EXCESS CO2"
That may indeed be a better way to put it, thanks for the suggestion.