01
Some sunlight is reflected
Clouds, ice, land, and ocean reflect different fractions of incoming sunlight. That fraction is called albedo.
Earth & space · 25 minutes
A planet must balance its energy
A planet warms when it absorbs energy faster than it loses energy. A warmer surface then radiates more infrared energy.
Keep this question in mindHow can a small change affect a whole climate?
01
Notice the problem
Every watt must eventually leave.
Reflection changes the input. Greenhouse absorption changes how easily infrared escapes.
340 W/m² arrives on averageEvery watt must eventually leave.
Reflection changes the input. Greenhouse absorption changes how easily infrared escapes.
02
Three things to notice
Look at these three ideas.
Each picture shows one part of the question. You will test the ideas next.
02
Warm matter emits infrared
Earth sends energy toward space as infrared light. Warmer surfaces emit more.
03
Greenhouse gases slow the escape
Water vapour, carbon dioxide, and other gases absorb some outgoing infrared and emit it in new directions.
03
Your prediction
What should a planet do after greenhouse absorption increases?
Choose what you think will happen. It is fine to be wrong. The experiment will help you find out.
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