Carbon Footprinting

What is a carbon footprint?

The adverse impact of human activity on the environment is an increasingly important issue affecting all areas of our lives. “Carbon footprinting” is a measure in both production and service sectors. A carbon footprint is defined as "the total set of GHG (greenhouse gas) emissions caused directly and indirectly by an individual, organisation, event or product" (UK Carbon Trust, 2008).

The most important GHGs, covered by the Kyoto Protocol, are carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride. Each GHG has a different capacity to cause global warming; this is defined by its “Global Warming Potential” (GWP). The Intergovernmental Panel on Climate Change (IPCC) uses GWPs to measure how much of a given mass of a GHG is estimated to contribute to global warming. A GWP is defined as the warming influence over a set period of time of a gas relative to that of carbon dioxide. The figure is then given as the total carbon dioxide equivalent, or CO2e.

Calculating the carbon footprint of products is a complicated process that requires a very detailed approach. It is important to use a consistent methodology to ensure an accurate, credible result that can be compared with other organisations or products. There are existing, recognised methods for carbon footprint calculation that are widely accepted and understood, for example PAS 2050, which was developed by the British Standards Institution (BSI). The updated edition released in 2011 is available to download from the BSI website:

What is the carbon footprint of flour?

Each flour will have its own carbon footprint that is closely linked to both agricultural production and the grain chain as a whole. The second largest source of GHGs, after the energy sector, is agriculture. However since 1990 emissions from the agricultural sector have been decreasing. 

Flour milling is the manufacturing stage, with wheat being the source ingredient. Flour would be classed as a “Business-to-Business” (B2B) product, rather than a “Business-to-Consumer” product (B2C), as it is processed for use in secondary products. Therefore, to consider the carbon footprint of flour production all stages up to the secondary producer must be considered.

Where can I find a carbon footprinting guide for wheat?

In 2012, AHDB published a carbon footprinting guide and decision support tool, which offers a straightforward and transparent way to calculate the carbon footprint of a particular crop and to test different scenarios to identify areas in which efficiency gains can be made.
This is available for download on the right or from the AHDB website.