Heat Trap

Heat Trap: the greenhouse effect, seen by the radiation itself

This free game is part of our AQA GCSE Chemistry (8462) course for exams in EXAM YEARS 2027-2029.

The greenhouse effect for AQA GCSE Chemistry

AQA GCSE Chemistry (8462) asks you to describe the greenhouse effect in terms of the interaction of short and long wavelength radiation with matter (spec 4.9.2.1), and to recall two human activities that increase each of carbon dioxide and methane (4.9.2.2). In a textbook it is three steps and an arrow diagram. The hard part is picturing what actually happens to the radiation on the way in and on the way out.

In Heat Trap you are the radiation. You dive in from the Sun, hit the ground and then try to escape back to space, while Dr Kira Lane from the Climate Satellite Team explains what is happening to you. Every rule in the game is the real science: what lets you through, what absorbs you, and where you go next.

Short wavelength in, long wavelength out

On the way down you are short wavelength radiation: a tight, fast wave. Nothing in the air absorbs you, not even the greenhouse gases, so you pass straight through every molecule. When you land, the surface absorbs you, warms up and gives out radiation of a longer wavelength. You see your own wave stretch out.

On the way up you are long wavelength radiation. Nitrogen and oxygen, almost all of the air, still let you through. But water vapour, carbon dioxide and methane molecules absorb you, vibrate, and re-emit you in a random direction, so sometimes you are sent straight back to the surface, which stays warmer. That is the greenhouse effect. The first level starts on a what-if Earth with no greenhouse gases at all: everything escapes and the average temperature would be about −18 °C. Put the natural greenhouse gases back and it climbs to about 14 °C, which is why greenhouse gases keep the Earth warm enough to support life.

Human activities that add carbon dioxide and methane

From the 1850s the landscape changes. A power station, a motorway and a logging site rise out of the ground, and each one puffs its molecules into the sky. Every ray you send in has to land on the source the satellite asks for. For carbon dioxide that means burning fossil fuels (in power stations, homes, factories and vehicles) and deforestation, because fewer trees take in carbon dioxide by photosynthesis and burning or rotting the felled trees releases it. A growing forest and a wind farm are there too, and landing on them costs you points.

From the 1960s come the methane sources: cattle, which release methane as they digest their food, rice paddy fields and landfill sites, where rotting material gives it off. As the years pass the sky fills with more carbon dioxide and methane, escaping gets harder and the thermometer climbs to about 1.3 °C above the late 1800s.

Judging the evidence on climate change

Two fact-check breaks cover the second half of 4.9.2.2. You swipe real-looking reports: trust or doubt. A cold winter in one town over three years, a peer-reviewed global temperature record, a report paid for by a coal company, a simplified climate model that gives a range, a campaign leaflet with no sources and a scientist explaining a peer-reviewed report on TV. Each one teaches a question to ask: is it peer reviewed, does it use the whole evidence or only part of it, could it be biased, and does it describe its uncertainties? You also learn why a simplified model is not the same as a wrong one, and why scientists communicate their results to a wide range of audiences.

Four levels, about 8 minutes

Level 1 has no clock and a guided first catch. Level 2 adds the carbon dioxide sources and level 3 the methane sources, each ending with a quick exam check. Level 4 is a 75-second rush through today's crowded sky. You also build the full exam answer to "describe the greenhouse effect" in the right order, avoiding the classic traps: greenhouse gases reflect heat, there is a hole in the atmosphere, or the Sun gives out the long wavelength radiation. A game takes about 8 minutes, works on a computer, tablet or phone, and saves your best score.