Imagine that you have two people using breathing gear under water. Diver 1 is using an old style “rebreather” that removes carbon dioxide before the mixture is “rebreathed” and therefore decreases overall carbon dioxide concentrations in the blood. Diver 2 is using regular SCUBA gear and is breathing air with the normal amount of carbon dioxide that does not lower blood levels of carbon dioxide. Which diver would have a higher blood pH and which would feel more an “urge to breathe”?