Heat Trap Simulator | Green Flask Science

Part A. The Photon Trace

Sunlight is visible light. Earth's surface absorbs it and gives off infrared (heat). Each time the surface absorbs energy it sends one infrared packet up. Count what happens to 100 packets of sunlight.

sunlightinfrared from the surfaceinfrared re-emitted by gas

Gas layer absorbs0%

Speed

0sunlight launched

0reflected by clouds and ice (30%)

0absorbed by the surface

0surface infrared emissions

0sent back down by the gas

0infrared escaped to space

Teacher: expected per 100 photons (30% reflected, 70 absorbed): no layer 70 emissions (about -18 C); 80% layer about 117 (about 17 C); 100% layer 140 (about 30 C). One 100-photon run varies by 10 or more counts because of chance, so have students run each setting several times or use the Average of 10 quick runs button. The model is simplified: every absorbed sunlight photon heats the surface, and the layer sends half of what it absorbs down and half up.

Run log

Run	Gas layer	Absorbed	Surface emissions	Escaped	Estimated surface temperature

Run at least two settings, including "No gas layer", to unlock the questions. One run is partly chance, so use "Average of 10 quick runs" to see the pattern clearly.

Part B. The Planet Lab

Tune a planet's distance from the Sun, its reflectivity, and the strength of its gas blanket. The model balances the sunlight a planet absorbs against the infrared it must send back to space.

Distance from the Sun

Reflectivity (albedo)

Gas blanket strength

Blanket strength counts layers of greenhouse gas. One full layer absorbs all the infrared from below and sends half of it back down. Venus has about a hundred layers' worth.

Sunlight absorbed per square meter

Surface temperature

Same planet with no gas blanket

White tick marks show where water freezes (0 C) and boils (100 C).

Planet data

Planet	Distance (AU)	Reflectivity	Blanket	Sunlight absorbed (W/m2)	Model surface (C)	NASA mean (C)

Teacher: Mercury absorbs the most sunlight (about 2,070 W/m2), Venus the least of the three inner planets besides Mars (about 156 W/m2), yet Venus is hottest. This is the key evidence that distance alone does not set temperature.

Challenge: a warmer Mars

Press the Mars preset. Mars averages about -63 C in this model. Change only the gas blanket strength until Mars averages between 5 C and 25 C.

Not yet.

Teacher: a blanket strength of about 1.9 to 2.4 layers puts Mars near 5 to 25 C in this model. Real Mars cannot be warmed this easily, because it lacks enough carbon dioxide to reach that blanket.

Part C. The Gas Gallery

A greenhouse gas absorbs infrared. Decide whether each gas in the air is a greenhouse gas. The first try counts.

Which gas traps the most heat per molecule?

Tap the four gases in order from weakest to strongest heat trapping per molecule over 100 years.

Your order: none yet

Teacher: carbon dioxide (1), methane (about 25 to 30), nitrous oxide (about 265 to 300), CFC-12 (about 10,000). Approximate 100-year global warming potentials; use the values from your textbook table when grading. Per molecule is not the same as total effect, because carbon dioxide is far more abundant.

Part D. The Verdict

Write a claim, evidence, reasoning (CER) answer to this question:

Why is Earth warm enough for life, and what would change if the amount of greenhouse gas changed?

Claim Evidence (use at least two numbers from this simulator) Reasoning (explain how the gas causes the change)

The claim says greenhouse gases keep Earth warmer than it would be without them.
The evidence includes at least two numbers.
The evidence names a planet or a simulator run (for example Venus, Mercury, or no gas layer).
The reasoning uses the words absorb and infrared.
The reasoning says the gas re-emits or sends energy back toward the surface.

Exit question

Your report

Type your first name or student ID. It stays on this device and is never sent anywhere.

Name or ID

Teacher: paste the student's name or ID and score from the report to check the completion code.

CER answer notes: claim that greenhouse gases keep Earth near 15 C instead of about -18 C; evidence such as 70 versus 140 emissions per 100 photons, or Venus at about 464 C absorbing less sunlight than Mercury; reasoning that the gas absorbs infrared and re-emits it in all directions, so some energy returns to the surface and the surface warms until outgoing infrared again equals absorbed sunlight.