Using coal, natural gas or oil for electricity, heat or transportation releases carbon dioxide into the atmosphere. The daily carbon dioxide emissions make up the

The total daily carbon dioxide released by using fossil fuels makes up a carbon footprint.

Carbon dating measures the age of once-living material and is unrelated to emissions accounting.

A carbon credit is a tradable permit, not the measure of emissions produced.

A carbon footprint sums the greenhouse gases attributable to a person, product or activity.

It is usually expressed in tonnes of carbon dioxide equivalent per year.

Individuals can shrink their footprint through cleaner energy and reduced consumption.