Carbon and water footprint: what are they?

We often hear about carboon footprint is water footprint, but what are they? Any reasoning about the environmental footprint and pollution in general can only start from the clear and unambiguous definition of these two concepts. For us the criteria that apply are those of Ministry of the Environment: they are challenging to read and even more to understand, but here they are in full.

What is the carbon footprint?

There carbon footprint is a measure that expresses in CO2 equivalent to the total of greenhouse gas emissions associated directly or indirectly with a product, organization or service. In accordance with the Kyoto Protocol, the greenhouse gases to be included are: carbon dioxide (CO2), methane (CH4), nitrous oxide (No.2O), hydrofluorocarbons (HFCs), sulfur hexafluoride (SF6) and perfluorocarbons (PFCs).

The tCOand (tons of CO2 equivalent) allows to express the greenhouse effect produced by these gases in reference to the greenhouse effect produced by CO2, considered equal to 1 (for example methane has a greenhouse potential 25 times higher than CO2, and for this one ton of methane is counted as 25 tons of CO2 equivalent).

The measurement of carbon footprint of a product or process requires in particular the identification and quantification of the consumption of raw materials and energy in the selected phases of its life cycle. In this regard, the experience of recent years suggests that the label of carbon footprint is perceived by consumers as a business quality and sustainability index.

Companies, in addition to conducting the analysis and accounting of CO emissions2, undertake to define a system of carbon management aimed at identifying and implementing those measures to reduce emissions, economically efficient, which use low-carbon technologies.

The reduction measures can be complemented by measures for the neutralization of emissions (carbon neutrality), achievable through activities that aim to offset emissions with equivalent measures aimed at reducing them with actions that are economically more efficient or more expendable in terms of image (eg tree planting, production of renewable energy, etc.).

What is the water footprint?

The water footprint is an indicator of fresh water consumption that includes both the direct and indirect use of water by a consumer or a producer. The water footprint of an individual, community or business is defined as the total volume of fresh water used to produce goods and services, measured in terms of volumes of water consumed (evaporated or incorporated into a product) and polluted per unit of time.

In defining the water footprint, importance is also given to the geographical location of the resource collection points. The water footprint assessment it is developed in three phases: 1) quantification and localization of the water footprint of a product or process in the reference period; 2) assessment of the environmental, social and economic sustainability of the water footprint; 3) identification of the reduction strategies.

The global calculation of the water footprint is given by the sum of three components: 1) Blue water: refers to the withdrawal of surface and groundwater intended for use for agricultural, domestic and industrial purposes; it is the quantity of fresh water that does not return downstream of the production process in the same point where it was withdrawn or returns there, but at different times; 2) Green Water: is the volume of rainwater that does not contribute to surface runoff and mainly refers to the evaporated-transpiring water for agricultural use; 3) Grey water: represents the volume of polluted water, quantified as the volume of water necessary to dilute the pollutants to the point that the quality of the water returns above the quality standards.

The use of the three components of virtual water affects the hydrogeological cycle in different ways. For example, the consumption of green water has a less invasive impact on environmental balances than the consumption of blue water. There water footprint it therefore offers a better and broader perspective on how the consumer or producer affects the use of fresh water. It is a volumetric measure of water consumption and pollution. It therefore does not measure the severity of the impact at the local level, but provides an indication of the space-time sustainability from the water resource used for anthropogenic purposes.

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