Screenshot of OFFSET game. play button

Keep Earth in balance!

Carbon dioxide (CO2) is a greenhouse gas. Too much of it in the atmosphere makes Earth too warm. In this game, you must balance CO2 sources with CO2 “sinks.” In other words, you must OFFSET all CO2 emissions so that Earth will not become too warm. To “offset” means to balance out or make up for.

A source of CO2 is anything that burns fossil fuel and produces CO2 as waste. CO2 sources in this game include coal-burning power plants and gasoline-powered cars. A CO2 “sink” is anything that takes CO2 out of the atmosphere. The CO2 sinks in this game are forests, because trees take in CO2 and give off oxygen (O2).

How to play:

When the game starts, you begin to earn money so you can buy “upgrades.”

Upgrade your sources. Buy clean wind energy farms or solar power arrays to replace dirty, coal-burning power plants. Buy new electric cars to replace your gasoline-powered cars.

Upgrade your sinks. Replant your forests, after the lumberjacks chop them down.

When you have enough money for an upgrade, its “price tag” turns green. Click on it to buy the upgrade.

Meanwhile, combat CO2 molecules using the paddle at the top of the screen to keep the CO2 molecules from escaping into the atmosphere. Move the paddle side to side to by dragging on it or dragging along the bottom of the screen. Or use the "A" key to move to the left and the "D" key to move it to the right.

The more CO2 molecules that escape into the atmosphere, the hotter the thermometer gets. When the red reaches the top of the thermometer, game over.

Find out more about carbon sources and sinks, and Earth’s carbon cycle.