fix(env): review elise

Author: ldecarvalho-doc

environmental-footprint/environmental-footprint/additional-content/assets/scaleway-allocation-rules-cross-funct-it-equip.webp

@@ -166,18 +166,6 @@ To integrate this into the overall calculation, we will first get the total envi
 
 ### Water consumption
 
-#### Understanding Water Usage Effectiveness
-
-Water Usage Effectiveness (WUE) is a metric used to measure the water consumption efficiency of a datacenter. It is defined as the amount of water used by a datacenter in liters, per kilowatt-hour (kWh) of energy consumed.
-
-The calculation is performed using the following formula:
-
-```
-WUE = Total Water Used (liters) ÷ Total IT Energy Consumption (kWh)​
-```
-
-#### How to calculate water consumption for each Scaleway service
-
 For each Scaleway product or service, we calculate the water consumption based on its energy consumption.
 
 To estimate the water consumption by multiplying the total energy consumption for each service by the WUE, as such:

environmental-footprint/environmental-footprint/additional-content/assets/scaleway-allocation-rules-customer-it-equip.webp

@@ -12,25 +12,69 @@ dates:
 
 ## DDV_DC (Datacenter Lifespan)
 
-This value indicates the lifespan of a datacenter, if the value is not available it can be estimated. For example `DDV_DC` = 10 years.
+This value indicates the lifespan of a datacenter, if the value is not available it can be estimated. For example `DDV_DC` = 25 years.
 
 ## dU (Duration of use)
 
-As defined by the [ADEME Product Category Rules (PCR)](https://librairie.ademe.fr/produire-autrement/6105-methodological-standard-for-the-environmental-assessment-of-datacenter-it-hosting-services-and-cloud-services.html), the dU or duration of use, is the measurement that indicates the time a device or a datacenter was used.
+As defined by the [ADEME Product Category Rules (PCR)](https://librairie.ademe.fr/produire-autrement/6105-methodological-standard-for-the-environmental-assessment-of-datacenter-it-hosting-services-and-cloud-services.html), the dU or duration of use, is the measurement that indicates the time a Scaleway resource such as an Elastic Metal server is used.
 
 ## Emission factor
 
 An emission factor is a coefficient that relates the amount of CO<sub>2</sub>eq emitted to a specific activity that generates that emission.
 This coefficient is used at Scaleway to estimate CO<sub>2</sub>eq emissions from various sources.
 
-## PuissCommDC
+## Environmental impact
 
-This value indicates the proportion of a datacenter's installed power reserved for users.
+Environmental impact refers to the set of effects that a human activity or product has on the environment.
 
-## PuissEqt (Rated power)
+In the context of digital services, and more specifically cloud infrastructures such as Scaleway's, this impact includes several main factors:
+
+  - **CO2 emissions (kgCO2eq)** - This is the amount of carbon dioxide (and other greenhouse gases) emitted directly or indirectly by the manufacture, use, and management of servers and other equipment necessary for the operation of cloud services. CO2 emissions are measured in kilograms of CO2 equivalent (kgCO2eq).
+  - **Energy consumption** - This is the electrical energy consumed by servers and associated infrastructures (networks, cooling, etc.) to ensure the proper functioning of cloud services. Energy consumption is a key factor because the production and use of electricity are often associated with CO2 emissions, depending on the energy sources used (fossil, renewable, etc.).
+  - **Water Consumption** - Water is used in data center cooling systems to keep servers at an optimal temperature. Water Usage Effectiveness (WUE) is an indicator that measures the amount of water used in relation to the energy efficiency of a data center.
+
+In short, the environmental impact is an estimated measure all the resources consumed and emissions generated by an activity or product, with the aim of minimizing negative impacts on the environment and promoting more sustainable practices.
+
+## Life Cycle Analysis (LCA)
+Life Cycle Analysis (LCA) is a method of assessing the environmental impact of a product, service or process throughout its life cycle, from the extraction of materials to the end of life.
+
+Typical stages of LCA include:
+  - Extraction and processing of raw materials
+  - Product manufacturing
+  - Distribution and transportation
+  - Consumer use
+  - End of life (recycling, disposal, etc.)
 
-This value indicates how much electrical power a particular device or piece of equipment consumes while it is operating. If a server requires 500 watts of power to run, then the PuissEqt for this server is 500 watts.
+For each stage of the life cycle, the environmental impact is assessed based on different indicators, such as energy consumption, greenhouse gas emissions, water consumption, waste production, etc.
+
+In the context of Scaleway, the LCA can be used to assess the environmental impact of the entire life cycle of cloud services, including the extraction of raw materials for the manufacturing of hardware equipment, energy production to power data centers, the manufacturing and distribution of IT equipment, the use of cloud services by customers, and the end of life of equipment. Data on energy consumption, greenhouse gas emissions, water consumption, waste production, etc., must also be collected and analyzed for each stage of the life cycle.
 
 ## mutualisation
 
 This  factor  is  equivalent to  [PuissEqt]() and PuissDisponibleDC, which is the nominal power available for Scaleway at the datacenter. For  shared  equipment, such as management  servers  and  network  equipment  of  the  datacenter,  this  factor  is  applied.
+
+## PuissCommDC
+
+This value is defined by the ADEME PCR as the proportion of a datacenter's installed power reserved for users.
+
+## PUE (Power Usage Effectiveness)
+
+PUE is a key indicator used to measure the energy efficiency of data centers. It was created by The Green Grid, an organization dedicated to improving the energy efficiency of datacenters.
+
+The PUE represents the ratio between the total amount of energy consumed by a datacenter and the energy used directly to power IT equipment (servers, storage, networks).
+
+It is a key factor in estimating the energy efficiency of data centers and, by extension, their environmental impact. The lower the PUE, the more energy-efficient the datacenter, which translates into lower greenhouse gas emissions and better sustainability performance.
+
+## PuissEqt (Rated power)
+
+This value is defined by the ADEME PCR as how much electrical power a particular device or piece of equipment consumes while it is operating. If a server requires 500 watts of power to run, then the PuissEqt for this server is 500 watts.
+
+## Water Usage Effectiveness
+
+Water Usage Effectiveness (WUE) is a metric used to measure the water consumption efficiency of a datacenter. It is defined as the amount of water used by a datacenter in liters, per kilowatt-hour (kWh) of energy consumed.
+
+The calculation is performed using the following formula:
+
+```
+WUE = Total Water Used (liters) ÷ Total IT Energy Consumption (kWh)​
+```