See carbonfootprint details from incpen.org.
Lifecycle assessment (LCA) quantifies the environmental burdens associated with a product, process or activity over its entire lifecycle, from production of the raw materials to disposal at end of life. It generates a series of lists of materials and energy, and environmental impacts. These cannot be added together into a single number because they are measures of very different things .
“Carbon footprinting” is a newer, measurement system of a small selection of parts of a complete LCA. Whereas LCA covers all quantifiable environmental impacts associated with the product, a carbon footprint covers just greenhouse gas emissions. A single unit of measurement is used, carbon dioxide equivalent, and a single value obtained.
What is a carbon footprint?
A carbon footprint represents the total emissions of carbon dioxide (CO2) equivalents from whatever source is being measured, within a defined system boundary.
Everything has a carbon footprint, and the “system boundary” describes the scope of what is being measured. For example, a carbon footprint may be assigned to
a person or household – emissions associated with the energy they use to heat their home, to power their appliances and drive their cars, the emissions involved in producing all the products they use and getting them to the point of sale, the emissions associated with the waste they produce, and their share of the emissions from the public transport and other services they use [see for example the INCPEN publication Toward Greener Households which looks at the energy cost of packaging in the context of other household purchases and activities]
a product – emissions associated with the entire lifecycle, from mining raw materials or raising animals for food, through the various stages of processing to the packaging and transport involved in getting the finished product to the point of sale, and then on to final use and disposal
a production plant – emissions associated with all of the plant’s operations
Why calculate carbon footprint?
With growing concern about the sustainability of modern lifestyles, there has come a demand for companies to measure and disclose the environmental impact of what they do. The two fundamental environmental issues are climate change and greenhouse gas emissions, and depletion of the earth’s resources. Carbon footprinting addresses the first of these.
A number of companies have experimented with carbon labelling some of their products, and in France it is proposed that carbon labelling or some other form of carbon declaration should become mandatory. However, an on-pack carbon footprint value may not help the consumer because:
There is little point in looking at the carbon label on shampoos and presumably choosing the lowest, because more than 90% of the carbon emissions depend on how much hot water is used to wash your hair.
Some products’ carbon value is constantly changing. Foodstuffs may be brought in from different places according to the season, and computers may be assembled from components bought in from different parts of the world as costs or exchange rates fluctuate
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