Procedures to determine the carbon footprint indicator

The „footprint „ has to trace all those emitted GHG, which are directly or indirectly related with the performed activities, to be able to analyse the life cycle. In the life cycle assessment (LCA) two methods are used: one is the downstream starting process analysis (PA), the other is the upstream started environmental input-output analysis (IOA).

• the PA was developed, to assess the environmental impact of individual products  during the life cycle from the production stage to  the end user stage (recycling) with other words  from (business to consumer, B2C). In the  assessment by using primary or secondary data good results can be obtained but as the system boundary has to be clearly defined, the credibility of the assessment is reduced and is cost and labour intensive
• the IOA serve an alternative solution to PA and is more economic. It can be used for the  assessment of products, product groups, companies and countries
• in order to avoid the gaps of the previous methods it was introduced the hybrid assessment method (hybrid LCA). With this method is it possible to use the advantages offered by the PA methods (e.g. the downstream starting process assessment, use of detailed data) and to avoid the fragile points (e.g. system boundaries), also to use the advantages of the IOA method (e.g. introducing the less important processes).

Which method to use? Before starting the work a quick IOA screening can be of helpful. In any case results efficiency, accuracy and cost factors should be evaluated. 

Examples to the standards, which use the PA and IOA life cycle assessment (details in the Standards menu)

• PAS 2050:2011: in Europe in 2008 for the first time Carbon Trust and DEFRA from UK launch  together the standard for the CF assessment of  products and services. In principle the standard is  based on the PA method, the IOA method is less  applied. In the next version tha standard will be improved by the application of the hybrid LCA.
  
• The World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD) together developed in 2009 two standards in the frame of GHG Protocol. One is the Product Life Cycle Accounting and Reporting Standard and the other is the Corporate (Scope 3/Supply Chain) Accounting and Reporting Standard. The standards mainly use the PA methods and less the IOA method The standards take in account all indirect corporate emissions, therefore make a distinction between Scope 1- 2- 3. The Scope 1. standard deals with the corporate own direct emissions, while the Scope 2 and 3 deals with the indirect (inputs from outside) emissions.
• the International Organisation for Standardisation (ISO) is developing a new product standard ISO 14067 Carbon Footprint of Products. The standard use mainly the PA assessment and secondly the IOA assessment. (Other works are made to develop a standard for the corporate carbon footprint, ISO 14069).

In the carbon footprint assessment based on the IOA method the consumption is taken in account at individual, local, regional or national level.

Example on the national level carbon footprint (CO₂e Mt/year)

(source: own, based on international data)

Note: the welfare countries has a higher GDP, a higher GHG emission, a higher energy consumption and a bigger carbon footprint. The sustainability level at the heating and transport is 5-6.

Beside the GHG formulated in the Kyoto Protocol several other gases are responsible for climate change. Each of them has a different Global Warning Potential (GWP). In order to have a common ground for the assessment the Intergovernmental Panel on Climate Change, (IPCC) introduced the GWP, which is the measure of the heating impact of CO₂during a 100 year period and is expressed in CO₂ equivalent (CO₂e). The carbon footprint is expressed in CO₂e.

The carbon footprint indicator is used with several aims, e.g. for quality commitments, the assessment of the life cycle of a product/service, individual/ corporate/national CF assessments, to save energy or to increase the energy efficiency, to communicate the assessment results to others (CSR), marketing purposes and for awareness rising or education.

It should be noted that, very similar products can have different carbon footprints as the input sources entering in the process, the life cycle steps,  data sources, system boundaries are different. For example related meat products, mineral water, shoes, services can have different CF.