A person or companies carbon footprint is caused by the emission of carbon dioxide due to the burning of fossil fuels. As this carbon dioxide is released into the atmosphere it typically accumulates there when there is not enough bio-capacity to turn it back into oxygen. Carbon dioxide is one of the greenhouse gases alongside, Water vapor, Methane, Ozone, Nitrous oxide and Chlorofluorocarbons.
When these gases remain in the atmosphere they cause the earth to heat up and as such are responsible for the melting of ice caps. Ultimately the destruction of natural habitats are a core reason for global warming and climate change, alongside heavy industry.
The more that an individual or entity contributes in terms of carbon dioxide emissions into the atmosphere, increases the size of that individual or entities’ carbon footprint.