If the entire world's population jumped into the ocean at the same time totally submerging themselves, sea level would rise by 0.0014mm, the thickness of a plastic bag. Here's my logic.
The average male weighs 82kg; female 70kg. Assuming a body density the same as water (hence why we float, but only just), that gives us 1g/cm3, or respective body volumes of 0.082 and 0.070 cubic metres.
With 1.01 males per female and a world population of 6.6bn, we have 3,316,417,910 males and 3,283,582,090 females with combined body volumes of 502,686,567 cubic metres. The world's oceans and seas occupy 361 million square kilometres of the world's surface, so evenly applying the volume to that area gives you 0.0014mm.
Jump in on your tod, and the water level will rise by a fifth of the width of an atom's nucleus.
Feel small?
