Water Footprint Flashcards
What is the water footprint?
Environmental management tool for products, proceesses and analyzing the water footprint of entire companies
What is the global water crisis?
Only 1 % of the global water reserves are useable freshwater & there huge differences in the regional distribution
–> some countries experience high physical water scarcity (e.g., central-asia, parts of Australia, southern Europe,…)
3 of 10 people do not have access to safe drinking water
(e.g., mostly in Africa)
6 of 10 people do not have access to basic sanitation services (e.g., Africa, some parts of Asia)
- -> different to water scarcity map
- -> can vary in countries themselves
Huge economic damage and many people are killed due to flooding, droughts, etc.
What is the terminology of the water footprint?
we analyze the freshwater inputs into a products life cycle and the waste water outputs or losses (evaporation, product integration) of the process.
What are the three terms to analyze the water footprint?
Water use: Total input of freshwater into a product system
Water consumption: Freshwater not returning to the originating river basin due to evapotranspiration, product integration or discharge into other basins and the sea
Water pollution: Water quality degradation
What is virtual water?
Water consumed/polluted along supply chains of products and organization:
Blue water: Consumption of ground-and surface water
–> Blue water consumption: “Loss” of blue water for originating river basin due to evapotranspiration,product integration or discharge in other basins or the sea
Green water: soil moisture available for plants
–> Green water consumption: “Loss” of green water due to evapotranspiration of rain water by plants
Gray water:polluted blue water
–> Gray water footprint: water polluted by waste water, measured by the volume of water required to dilute waste water until quality standards are reached
How much water do we need every day?
direct water use: around 130 L/d
water use due to our consumption of food, clothes, etc.: 4000L/d
If we can reduce our water waster in food and fashion production, we could have a big impact.
What is the problem of the high water usage?
It depends on the local usage/ consumption of water: for example with cotton that is very thirsty and in the desert
almonds are also very thirsty in California and there is a huge depletion of water
milk from European cows is probably ok
What are the limits of virtual water?
Very good for raising awareness!
•Relevance of green water is controversial:
–Only locally available for plants, not for surrounding ecosystems or humans
–Green water consumption of (agricultultural evapotranspiration) should be seen in comparison to evapotranspiration of natural land –> net green water footprint
•Grey water is dependent on quality standards chosen (depends on chosen natural background concentration, quality standards in law,..)
•Amounts of blue, green and grey water consumption are usually added up
–> Implication of equality for which a scientific rationale is lacking
•Volume of water consumption does not allow for any statement regarding impacts on local human health (water-rich vs water sscarce regions) and ecosystems
What is the water footprint according to ISO?
Water footprint = „water shoesize“ * weight
Water footprint:
Impacts of water use along a product life cycle
„water shoesize“:
Volume of consumed water
weight:
–> adds the environmental meaning
- Local water scarcity
- Local sensitivity of population (wealth, medical care, etc.)
- Local sensitivity of ecosystems
- Type of watercourse (river, lake,..–>they have different functions and therefore different environmental impacts)
- Water quality
- Time of water use (dry/wet season)
What is the definition of the ISO water footprint?
A water footprint assessment addresses the potential environmental impacts related to water associated with a product, process or organization.”
What is WAVE?
An example for the weighting factor of the water footprint
–> Water Accounting & Vulnerability Evaluation
Explain WAVE.
- Model quantifies local water scarcity in > 8,000 river basins around the globe in monthly resolution
- Refers to the risk of depriving other users of fresh water when consuming water in a river basin
–> water stress in the world changes depending on the time of the year
give an example of different weighting.
1 l milk from germany needs 1000L/d
1l beer from Australia needs 300L/d but still has a bigger impact due to its origin from a water scarce region
How can water stress be mitigated with the results of the water footprint?
The impact is highest in the supply chain = harder to control
–>usually suppliers in other countries who you cannot control easily but the leverage is higher than on the production site = easier to control.
–Water Stewardship: Take collective action at local hotspots in global supply chains with suppliers and stakeholders –> sit at one table & discuss
–Eco-design: Analyze a product’s water use along its life cycle in the design phase
–> Optimization by water efficient material and design choices
–Sustainable procurement: Purchase of water efficient materials & improve water management at suppliers
