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Sea Level Rise

(See "Climate Detectives" fact sheet)

Materials:

Electric hot plate, heat-resistant drinking
glass, cake pan, water, ice cubes.

First Part—To Prove That:

Water expands when heated. As the Earth's
atmosphere traps more heat, the oceans will
warm and expand—and sea level will rise.

Procedure:

Fill the glass with very cold water. Make
sure to fill the glass almost to overflowing,
so the water is right at the rim's edge.

Place the glass in the cake pan, put the pan
on the hot plate, and turn the heat to the
lowest setting. Wait several minutes.

What happens to the water?

Does it expand?

Second Part—To Prove That:

Ice that is already floating on the ocean does
not raise the sea level when it melts. Melting
glaciers, however, do raise sea level slightly.

Procedure:

Put two ice cubes in the glass and then fill
with water, almost to overflowing. Watch
the water level as the ice melts.

What happens?

Does the water overflow?

After the ice has melted, put another piece
of ice in the glass.

What happens?

Why would sea level rise from a melting
glacier, but not from a melting iceberg?

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The Greenhouse Effect

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(See "Check out the Greenhouse Effect"
fact sheet)

Use either I or II

Materials:

1 empty plastic soda bottle (two-liter size)
with a cap, a nail, two thermometers.

To Prove That:

A transparent or semitransparent covering
traps heat, just as gases in the atmosphere
trap heat like a greenhouse.

Procedure:

Both thermometers and the bottle should
be outdoors on the ground in full sunlight.
Using the nail, make a hole near the top
of the plastic bottle. Place one of the
thermometers in the hole. Place the other
thermometer outside the bottle, next to it
on the ground. Be sure that both
thermometers are receiving the same
amount of sunlight.

What happens?

Do both thermometers register the same
temperature?

If not, which one is higher?

Why?

Materials:

2 thermometers, use of a car.

To Prove That:

A transparent covering traps heat,
just as gases in the atmosphere
trap heat like a greenhouse.

Procedure:

Take the class or group to the presenter's
or teacher's car. Place one of the
thermometers in the car. Place the other
thermometer outside the car. Be sure that
both thermometers are receiving the same
amount of sunlight.

What happens?

Do both thermometers register the same
temperature?

If not, which one is higher?

Why?

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