What is a "Carbon Footprint"?

A carbon footprint is a measure of the impact our activities have on the environment, and in particular climate change. It relates to the amount of greenhouse gases produced in our day-to-day lives through burning fossil fuels for electricity, heating and transportation etc. The carbon footprint is a measurement of all greenhouse gases we individually produce and has units of tonnes (or kg) of carbon dioxide equivalent.

The pie chart above shows the main elements which make up the total of an typical person's carbon footprint in the developed world.

A carbon footprint is made up of the sum of two parts, the primary footprint (shown by the green slices of the pie chart) and the secondary footprint (shown as the yellow slices).

1. The primary footprint is a measure of our direct emissions of CO2 from the burning of fossil fuels including domestic energy consumption and transportation (e.g. car and plane). We have direct control of these.

2. The secondary footprint is a measure of the indirect CO2 emissions from the whole lifecycle of products we use - those associated with their manufacture and eventual breakdown. To put it very simply – the more we buy the more emissions will be caused on our behalf.

To calculate your carbon footprint - click here

For tips to reduce your footprint - click here

Further definitions of "Carbon footprint" on the Web:

• A carbon footprint is a "measure of the impact human activities have on the environment in terms of the amount of greenhouse gases produced ...
  en.wikipedia.org/wiki/Carbon_footprint

• A measure of the amount of carbon dioxide produced by a person, organization or state in a given time
  en.wiktionary.org/wiki/carbon_footprint

• A form of carbon calculation that measures the amount of carbon dioxide equivalent that a country, a business, an industry or an individual produces or is responsible for. The footprint calculates the direct and indirect level of CO 2 -e emissions. ...
  www.epa.vic.gov.au/climate-change/glossary.asp

• A Carbon Footprint is made up of the sum of two parts, the direct / primary footprint and the indirect / secondary footprint. ...
  www.city-carpets.com/ContentPage.aspx

• The total amount of carbon dioxide and other greenhouse gases emitted into the atmosphere during one's life, or during the time it takes to ...
  www.cookiemag.com/homefront/2007/09/greenglossary

• Total emissions of greenhouse gases from source being measured, eg an individual or organisation.
  www.prospects.ac.uk/cms/ShowPage/Home_page/Explore_job_sectors/Environmental__food_chain_and_rural/jargon_buster/p!ejFdgk

• The estimated emissions of carbon dioxide (CO2) and other GHGs associated with a particular activity (eg a plane trip), use of your car, your family’s overall lifestyle, or use of a particular product or service. ...
  www.tcnj.edu/climate/GlossaryofTerms.htm

• Your carbon footprint is the sum of all CO2 emissions that are directly and indirectly associated with your activities over a given time frame ...
  www.carbondescent.org.uk/glossary.php

• A measure of the amount of greenhouse gases emitted because of one’s activities. These can be tracked at global, state, or local levels as well as by companies and individuals. ...
  www.clackamas.us/sustainability/glossary.htm

• The term "footprint" is frequently used incorrectly to describe a GHG Inventory. This term actually refers to the amount of productive land (forest) required to sequester (remove) the equivalent amount of GHGs that a company emits. ...
  www.triplepundit.com/pages/carbon-market-terminology-deci-003010.php

• A measure of an individual's, family's, community's, company's, industry's, product's or service's overall contribution of carbon dioxide and other greenhouse gases into the atmosphere. It takes into account energy use, transportation methods and other means of emitting carbon. ...
  www.firemansfund.com/servlet/dcms

• The overall amount of carbon dioxide produced from human activities. Climate change is attributed mostly to increased levels of carbon dioxide. Click here for more.
  www.carbondiet.ca/going_green/green_terms.html

• A measure of the greenhouse gas emissions attributable to an activity; it is commonly used at an individual, household or business level.
  www.organicguide.com/blog/thinking-green/glossary-of-climate-change-terms/

• The total carbon emissions for a given person, organization, building, operation etc. The carbon footprint of an operational office typically include the carbon emitted by the commuting of the office staff. Wikipedia - Carbon footprint
  www.astralweb.co.uk/smart-meters-glossary.html

• The amount of greenhouse gas emitted each year through direct (such as driving) and indirect (such as electrical purchases) sources.
  standardcarbon.com/resources/

• The amount of carbon released by subject (human, building, factory, production and so on), how much carbon is being produced as a result of specific actions. ...
  www.aronsoncustomhomes.com/greenbuilding-glossary.html

• Means (in tonnes of carbon dioxide equivalent) Greenhouse Gas emissions associated with the Sites determined in accordance with the Project Andromeda™ Carbon Footprint Methodology
  www.projectandromeda.com/terms2.html

• The total amount of GHGs emitted by activities, such as electricity use and travel, over a certain period of time. ...
  talklessdomore.org/whysustainability/greenglossary.html