The amount of carbon dioxide released into the atmosphere (during energy generation) is calculated and an investment is made in a scheme that removes the same amount of carbon dioxide from the air.
Because trees absorb carbon dioxide as they grow, they are often used as a means of capturing carbon dioxide, but there are lots of other types of off-setting program.
Other examples include investment in renewable energy schemes. More examples of carbon offsetting schemes.
Supporting verified carbon offsets provides essential finance to renewable energy and resource conservation projects which would not otherwise happen. Some of the best schemes also have benefits to communities, biodiversity and/or animal conservation.