Brighter Planet

What units and measures are used for carbon footprints and offsets?

“Carbon dioxide equivalent” (CO₂e) is the industry standard way of describing the climate impact of different types of greenhouse gas.

Carbon dioxide is the main greenhouse gas, so other gasses’ climate impact is expressed relative to CO₂:

• 1 unit of carbon dioxide = 1 unit of CO₂e
• 1 unit of methane = 25 units of CO₂e
• 1 unit of nitrous oxide = 298 units of CO₂e

As you can see, methane and nitrous oxide are much more potent greenhouse gases than carbon dioxide. That’s why farm methane digesters like those Brighter Planet members support are such great projects—they convert methane to less-harmful CO₂ and create heat or electricity at the same time!

What is a ton?

In the U.S. carbon offset market, organizations typically use “short tons” as the unit of mass.

• 1 short ton = 2000 pounds (lbs)
• 1 short ton = 907 kilograms (kg)
• 1 short ton = 0.91 metric tonnes

What is a greenhouse gas (GHG)?

Some greenhouse gases (GHG) occur naturally in the atmosphere, such as water vapor, carbon dioxide (the most common greenhouse gas), methane, nitrous oxide, and ozone. Other gases, like those used for aerosols, are man-made. Greenhouse gases absorb radiation from sunlight and trap the heat in the atmosphere, a process referred to as the “greenhouse effect.” Certain human activities, primarily the burning of fossil fuels, add to the levels of these naturally occurring gases. Overly abundant GHG speed up the warming greenhouse effect.