Carbon footprint

A life cycle assessment (LCA), also known as life cycle analysis, of a product or process begins with an inventory of the energy and environmental flows associated with a product from "cradle to grave" and provides information on the raw materials used from the environment, energy resources consumed, and air, water, and solid waste emissions generated. GHGs and other wastes, sinks, and emissions may then be assessed (Sheehan et ah, 1998). The net GHG emissions calculated from an LCA are usually reported per imit of product or as the carbon footprint. 

Rotz, C. A., Montes, F., and Chianese, D. S. (2010). The carbon footprint of dairy production systems through partial life cycle assessment. J. Dairy Sci. 93,1266-1282. 

Carbon Footprint as a Tool to Limit Greenhouse Gas Emissions... 

Keywords Carbon Footprint, ISO 14067, GHG, Life Cycle Assessment... 

Table 1. Carbon footprint of continents and most important nations [3]...

Carbon footprint is most appropriately calculated using life-cycle assessment or input-output analysis [3,4]- In this sense it is based on the ISO 14040 [4] and ISO 14043 [5] norms, on life cycle assessment (LCA). Specific norms for carbon footprint of enterprises and products are ISO 14064 (part 1,2, and 3) [6-8], ISO 14067 [9], and PAS 2500 [10]. Carbon footprint calculation process is shown in Figure 1. 

Carbon Footprint as a Tool to Limit Greenhouse Gas Emissions 287 http //dx.doi.Org/10.5772/62281... 

Main emissions due to the most important processes are added through the whole life cycle. Carbon footprint of a purchased good or service can be calculated using Equation 1 [11]. 

In order to calculate carbon footprint, it is very important to consider the boundaries of the process which emissions should be considered in calculation of the footprint This problem can be solved by considering three definitions Scope 1, Scope 2, and Scope 3. 

The carbon footprint of transport fuels has been analyzed in several studies starting from 1990. One of the most important is the study realized by Sheehan et al. [13] at National Renewable Energy Laboratory of the United States.This is an LCA study that includes the impact of C02 emissions. Most important operations belonging to the petroleum diesel product system include crude oil extraction, its transport to an oil refinery, crude oil refining to diesel fuel, its transportation to the user, and its use in a bus engine. 

Carbon footprint of electricity generation through fossil fuels... 

Figure 3. Carbon footprint of different heating fuels [18]...

Carbon footprint of transport biofuels (biodiesel, bioethanol, biomethane)... 

The carbon footprint of electricity generation through RES (Renewable Energy Systems) are described in this section. Elydro-electricity is described first, and then wind power, followed by bioenergy systems and solar energy. 

Carbon footprint of residential heating systems based on renewable energy... 

Figure 5. Carbon footprint of different types of food products at retail. Average values estimated to be representative for food products sold on the Swedish market. Error bars show ranges of values found in the literature. Emissions from land use change and carbon stock changes in soils are not included [47]...

Another issue is represented by dairy production and the carbon footprint of milk [56,50], An important area of research is the production of animal feed for the different diets used in livestock production [57-58],... 

Ligure 6 presents the carbon footprint of cotton textiles and of synthetic textiles. In the case of cotton, different yarn thickness are taken into account. They are expressed on dedtex (abbreviated dtex). In the case of synthetic textiles, only yam thickness of 70 dtex is taken into account. 

Figure 6. Carbon footprint of cotton textiles with yarn thickness comprised between 70 and 300 dtex (left) and synthetic textiles - acryl, nylon, PET, elastane-, with yarn thickness of 70 dtex (right) [59]...

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