A Carbon Footprint is defined as "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.
Despite its ubiquitous appearance, there is no consensus on how to measure and quantify a Carbon Footprint. Owning to a lack of common and harmonized rules, the spectrum of definitions ranges from direct CO2 emissions to full life-cycle GHG emissions. The most central methodological issue is whether the calculation must include indirect emissions embodied in upstream production processes or whether it is sufficient to look at just the direct, on-site emissions of the product, process or person under consideration.
This discrepancy may cause uncertainty and confusion in the users. A credible answer can be constituted by Climate Declarations.
Climate Declarations are a further development of Environmental Product Declarations (EPD). An EPD shows the environmental impact of a product or service throughout its life cycle. A Climate Declaration is an excerpt of all climate-related data from an EPD, declared in so-called CO2equivalent.
When calculating the climate impact for a product or service it is important to take into account a number of greenhouse gases, such as carbon dioxide, nitrous oxide, methane etc. One must also calculate the emissions size for the whole life cycle. The Climate Declaration provides information on during which life cycle stage the emissions occur and the amount of greenhouse gases that is emitted.
The method for producing climate declarations follows relevant standards from the International Organization for Standardization; for life-cycle analysis (ISO 14040 and 14044) and for environmental declarations (ISO 14025). Climate Declarations are also reviewed and approved through an independent verification.
Carbon offsetting can be linked with Climate Declarations in order to compensate for the emissions produced by funding an equivalent carbon dioxide saving somewhere else. Different paths can be followed for this aim: carbon offset labels, reforestation projects, VER (Verified Emission Reduction) purchase from voluntary registries. This last solution guarantees the actual realization of the offsetting indeed.
A VER (Verified Emission Reduction) is a reduction of one metric ton of greenhouse gases emissions (expressed as CO2 equivalent) below a baseline or business-as-usual level (Dayal, 2007). VER carbon credits are a financial instrument that allow individuals and organizations to "balance" emissions of greenhouse gases produced in one place by helping fund emission reductions that occur elsewhere.
VER's registries keep track of the offsets and are vital in minimizing the risk of double-counting (i.e. to have multiple stakeholders taking credits for the same offset.) Registries also clarify the ownership of offsets. A serial number is assigned to each VER (or stock). When an offset is sold, the serial number and "credit" for the reduction is transferred from the account of the seller to the account of the buyer. If the buyer "uses" the credit by claiming it as an offset against their own emissions, the registry permanently retires the specific serial number so that the credit cannot be resold.
An example of VER registry is the eCO2care Carbon Account Registry, managed by CE.Si.S.P, (www.eco2care.org) that gives access to the processes certified by an independent third party, since only projects with a defined baseline, i.e. with a referring scenario for measuring CO2 emissions reduction, can be considered eligible to generate VERs.