Emission of greenhouse gases (GHG) such as carbon dioxide, methane, HFC and others is a consequence of the development of human activities. Many natural processes emit GHG, but anthropogenic GHG emissions have increased by a factor of 145 since 1750 and, although the greenhouse effect is necessary for life on earth, an increase will result in higher temperatures and a risk of climate change. Unfortunately, it is difficult to measure directly this phenomenon, for example in terms of temperature change (°C).
We usually measure GHG emissions by taking into account the emission of many gases having various greenhouse effects. Each quantity of gas released into the atmosphere must be multiplied by an emission factor and all gases are then added together. This results in a “carbon footprint” expressed in a CO2 equivalent mass of gas that can be expressed as kgéqCO2.
The carbon footprint can be measured for a country, a city, a company or a product. Product Carbon Footprint (PCF) can be used in the design process of greener products. The communication of PCF results is more problematic since it could lead to biased comparison of products because there are so many different methodologies. One could take into account the full lifecycle of the product, from raw material extraction to the end of life treatment, including usage. One could take into account only the manufacturing phase. In addition, other choices can impact the final CO2 equivalent value; for pumps, these are mainly assumptions on use phase conditions. Hence, the publication and use of carbon footprint must be made in accordance with standards.
It has been shown many times that for pumps electricity consumption during the use phase is the main source of GHG emission. However depending on the primary energy used, the value of CO2 equivalent can vary greatly. We cannot trace the origin of the energy usually coming from the network and we must calculate an average value corresponding to the energy mix of the supplier, of the country or of the continent. The “CO2 content” of a product generally refers to the GHG emissions from the raw material extraction to the manufacturing phase.
The environmental footprint aims to show the environmental impact of a product or an organisation. Climate change and GHG (i.e. carbon footprint) are included, but other environmental impacts are taken into account such as resource depletion, water and soil pollution… Similarly to the carbon footprint, the choice of the life-cycle stages to include in the calculation and many other assumptions will affect the result, making comparison of products very difficult if the footprints are not calculated according to the same standard.