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).