What are CO2 equivalents?

We use CO2 equivalents to collectively express the human impact on the atmosphere, and to make it tangible and calculable. However, CO2 is not the only gas that is emitted in large quantities by our activities that influences the climate. Methane, for example, is another gas that is released in excessive quantities due to human activity. 1 gram of methane impacts the climate about 25 times more than 1 gram of CO2. Therefore, 1 gram of methane corresponds to 25 grams of CO2 equivalents.