From Wikipedia, the free encyclopedia
A carbon footprint is “the total set of GHG (greenhouse gas) emissions caused directly and indirectly by an individual, organization, event or product” (UK Carbon Trust 2008). An individual, nation or organization's carbon footprint is measured by undertaking a GHG emissions assessment. Once the size of a carbon footprint is known, a strategy can be devised to reduce it.
Carbon offsets, or the mitigation of carbon emissions through the development of alternative projects such as solar or wind energy or reforestation, represent one way of managing a carbon footprint.
 Reducing a carbon footprint
The carbon footprint can be efficiently and effectively reduced by using a Carbon Diet or applying the following steps:
- Life Cycle Assessment (LCA) to accurately determine the current carbon footprint
- Identification of hot-spots in terms of energy consumption and associated CO2-emissions
- Where possible, changing to another electricity company to switch to buying electricity from renewable sources (from wind turbines, solar panels or hydroelectrical plants -or- from nuclear power plants
- Optimisation of energy efficiency and, thus, reduction of CO2-emissions and reduction of other GHG emissions contributed from production processes
- Identification of solutions to neutralise the CO2 emissions that cannot be eliminated by energy saving measures. This last step includes carbon offsetting; investment in projects that aim at the reducing CO2 emissions, for instance tree planting.
 Kyoto Protocol, carbon offsetting, and certificates
Carbon dioxide emissions to air (and the emissions of other GHG's) are almost exclusively associated with the conversion of energy carriers like natural gas, crude oil, etc.
The Kyoto Protocol defines legally binding targets and timetables for cutting the greenhouse-gas emissions of industrialized countries that ratified the Kyoto Protocol. Accordingly, from an economic or market perspective, one has to distinguish between a mandatory market and a voluntary market. Typical for both markets is the trade with emission certificates:
 The mandatory market
To reach the goals defined in the Kyoto Protocol with least economical costs the following flexible mechanisms were introduced for the mandatory market:
The CDM and JI mechanisms specify requirements for projects which create a supply of emission reduction instruments, whilst Emissions Trading allows those instruments to be sold on international markets.
- Projects which are compliant with the requirements of the CDM mechanism
Emissions Reductions (CERs).
- Projects which are compliant with the requirements of the JI mechanism generate Emissions Reduction Units (ERUs).
The CERs and ERUs can then be sold through Emissions Trading. The demand for the CERs and ERUs being traded is driven by:
- Shortfalls in national emission reduction obligations under the Kyoto
- Shortfalls amongst entities obligated under local emissions reduction schemes.
Nations which have failed to deliver their Kyoto emissions reductions
obligations can enter Emissions Trading to
purchase CERS and ERUs to cover their treaty shortfalls. Nations and groups of
nations can also create local emission reduction schemes which place mandatory
CO2 targets on entities within their national boundaries. If the rules of a
scheme allow, the obligated entities may be able to cover all or some of any
reduction shortfalls by purchasing CERs and ERUs through Emissions Trading.
While local emissions reduction schemes have no status under the Kyoto
Protocol itself, they play a prominent role in creating the demand for CERs
and ERUs, stimulating Emissions Trading and
setting a market price for
A well-known mandatory local emissions trading scheme is the EU Emission Trading Scheme (EU ETS).
 The voluntary market
In contrast to the strict rules set out for the mandatory market, the voluntary market provides companies with different options to acquire emissions reductions. A solution, comparable with those developed for the mandatory market, has been developed for the voluntary market, the Verified Emission Reductions (VER). This measure has the great advantage that the projects/activities are managed according to the quality standards set out for CDM/JI projects but the certificates provided are not registered by the governments of the host countries or the Executive Board of the UNO. As such, high quality VERs can be acquired at lower costs for the same project quality. However, at present VERs can not be used in the mandatory market.
The voluntary market in North America is divided between members of the Chicago Climate Exchange and the Over The Counter (OTC) market. The Chicago Climate Exchange is a voluntary yet legally binding cap-and-trade emission scheme whereby members commit to the capped emission reductions and must purchase allowances from other members or offset excess emissions. The OTC market does not involve a legally binding scheme and a wide array of buyers from the public and private spheres, as well as special events that want to go carbon neutral.
There are project developers, wholesalers, brokers, and retailers, as well as carbon funds, in the voluntary market. Some businesses and nonprofits in the voluntary market encompass more than just one of the activities listed above. A report by Ecosystem Marketplace shows that carbon offset prices increase as it moves along the supply chain——from project developer to retailer. .
While some mandatory emission reduction schemes exclude forest projects, these projects flourish in the voluntary markets. A major criticism concerns the imprecise nature of GHG sequestration quantification methodologies for forestry projects. However, others note the community co-benefits that forestry projects foster. Project types in the voluntary market range from avoided deforestation, afforestation/reforestation, industrial gas sequestration, increased energy efficiency, fuel switching, methane capture from coal plants and livestock, and even renewable energy. Renewable Energy Certificates (RECs) sold on the voluntary market are quite controversial due to additionality concerns.. Industrial Gas projects receive criticism because such projects only apply to large industrial plants that already have high fixed costs. Siphoning off industrial gas for sequestration is considered picking the low hanging fruit; which is why credits generated from industrial gas projects are the cheapest in the voluntary market.
The size and activity of the voluntary carbon market is difficult to measure. The most comprehensive report on the voluntary carbon markets to date was released by Ecosystem Marketplace and New Carbon Finance in July 2007..
 Carbon Labelling
A carbon label,
which shows the life cycle carbon emissions or carbon footprint embodied in a
product in bringing it to the shelf, was introduced in the UK in March 2007 by the Carbon Trust. The label is
closely linked to a collaboration between The Carbon Trust and
Standards Institute. The label is intended to comply with a new British
Standard, PAS2050, () and is being actively piloted by The Carbon Trust and
various industrial partners ().
Examples of products which already feature this carbon footprint label include Walkers Crisps, a smoothie product from Innocent Drinks, and a shampoo product produced by Boots Group.
 Age-related carbon footprint
A number of studies have calculated the carbon footprint of organisations and nations. One UK study by the Stockholm Environment Institute (Gary Haq et al, 2007) examined age-related carbon emissions based on expenditure and consumption. The study found that on average people aged 50-65 years have a higher carbon footprint than any other age group. Individuals aged 50-55 years old have a carbon footprint of approximately 13.5 tonnes/capita per year compared to the UK average of 12 tonnes.
 Carbon footprint for various types of electricity production
|It has been suggested that this article or section be merged into Life cycle assessment. (Discuss)|
The following table compares the carbon footprint of various forms of energy generation, from a study of full life cycle emissions by the Swedish utility Vattenfall of Nuclear, Hydro, Coal, Gas, Solar Cell, Peat and Wind generation technology ( and ), from the United States Environmental Protection Agency figures  and from various other studies.
|Technology||g/kWh Vattenfall (Sweden)||g/kWh EPA||g/kWh other|
|Gas (combined cycle)||450|
|Nuclear||3.10 Forsmark Nuclear Power Plant |
|Nuclear||5.05 Torness Nuclear Power Station |
The Vattenfall study thus concluded that hydroelectric and nuclear power produced the least CO2 per kilowatt-hour of any of their electricity sources. These figures do not allow for emissions due to accidents or terrorism. Lastly some relatively new green renewable electricity generation methods such as geothermal power emit no carbon during operation, but do leave a minor footprint during contruction phase using the cradle-to-grave approach of the complete production life cycle.
 Carbon footprint for various form so heat supply for buildings
The previous table gives the carbon footprint per kWh of electricity generated, which is about half the worlds man made CO2 output. The CO2 footprint for heat is equally significant and is contained in the following table  IT shows that using waste heat from power generation has the lowest carbon footprint.
 Holidays as extra environmental burden
An analysis of the carbon footprint of Christmas in the UK shows that consumption of items such as food, travel, lighting and gifts at Christmas produces as much as 650 kg of carbon dioxide (CO2) emissions per person - equal to 5.5% of the UK annual carbon footprint. Over Christmas, the average person could produce as much as:
- 26 kg of CO2 from Christmas food
- 96 kg of CO2 from Christmas Car travel
- 218 kg of CO2 from extravagant lighting displays
- 310 kg of CO2 on Christmas Shopping
Christmas carbon emissions could be reduced by up to 60 percent to about 250 kg. 
 See also
- ^ http://www.nytimes.com/2008/02/17/magazine/17wwln-safire-t.html
- ^ ClimateTalkReport_V7AB.indd
- ^ ENG 30966_Lca_DivK
- ^ nuclearinfo.net. Greenhouse Emissions of Nuclear Power
- ^ Electric Power Industry CO2 Emissions accessed 20 October 2007
- ^ Vattenfall 2004, Forsmark EPD for 2002 and SwedPower LCA data 2005.
- ^ Energy Analysis of Power Systems accessed 20 October 2007
- ^ The carbon footprint of christmas
- UK Carbon Trust (2008) "Carbon Footprinting".
- Parliamentary Office of Science and Technology POST (2006). Carbon footprint of electricity generation. October 2006, Number 268
- Wiedmann, T. and J. Minx (2008). A Definition of 'Carbon Footprint'. Ecological Economics Research Trends. C. C. Pertsova: Chapter 1, pp. 1-11. [[Nova Science Publishers, Inc, Hauppauge NY, USA. https://www.novapublishers.com/catalog/product_info.php?products_id=5999, also available as ISA-UK Research Report 07/01 from http://www.censa.org.uk/reports.html.
- World Energy Council Report (2004). Comparison of energy systems using life cycle assessment.
- Energetics (2007). The reality of carbon neutrality.
 External links
- A Definition of Carbon Footprint ISA Research and Consulting United Kingdom
- Carbon Footprint: what it is and how to measure it European Commission
- Introduction to Life Cycle Assessment European Commission
- LCA Resources Directory European Commission
- Carbon footprint calculator The Nature Conservancy