Fill a large beaker with 1000 mL of water containing a few drops of blue food coloring for effect.
This represents all the water on Earth.
Pour 30 mL of this water into a 100mL graduated cylinder.
This smaller amount represents all the freshwater on the planet.
Pour salt into the remaining 970 mL to simulate ocean water unsuitable for human |
The 30 ml of freshwater now in this graduate represents all the freshwater on the planet.
Most of this freshwater is frozen in ice caps and glaciers unavailable for human consumption.
Pour 6 mL of this water into a 10 mL graduated cylinder.
This represents all the non-frozen freshwater.
Place the remaining 24 mL into a freezer or picnic cooler of ice. |
The 6 mL of freshwater now in this small graduate represents all the non-frozen freshwater on the planet.
Use a 1 ml eyedropper to extract approximately 1.5 mL of water from the small graduate.
This full eyedropper represents all the fresh surface water on the planet.
Pour the remaining 4.5 ml onto the soil of a potted plant to represent ground water too deep for use. |
The 1.5 mL of water now in the eyedropper represents all the freshwater on the surface of the planet.
Wait until everyone is quiet with anticipation, and then announce that all of the planet's available clean freshwater that isn't polluted amounts to…
…a drop in a bucket! |
