"The more man-made carbon dioxide we put into the ocean, the shallower those saturation points will become, " says Mathis.

Olefin (or alkene) Any unsaturated hydrocarbon containing one or more pairs of carbon atoms linked by a double Bond (see covalent Bond, saturation).

With a blood saturation of 10% to 20% carbon monoxide, a tightness across the forehead and a slight headache are the only sensory changes observed.