Over the last few centuries, the emergence of more waste in the world and greater use of natural resources has led to unsustainable change. For this reason, a calculation such as the environmental footprint has emerged in the recent past to measure the impact of humanity on the environment. In fact, in the last 20 years, this term has been further developed and formed the basis for many different footprint concepts.
Today, the current environmental footprint of humanity does not constitute a fixed value but has lost its sustainable structure due to more land use, more water uses and more resource use. For example, while the water footprint, which is an important variety, emerged as an idea in 2002, it was introduced to the whole world with the first estimates at the end of the same year.
The water footprint shows the amount of water use of an individual or a country’s society against the background of goods/services consumed. In this way, the total water footprint of an individual or a nation can provide a useful indicator for the nation and nations for the international community. In the context of global water resources and consumers, it has also proved to be of great benefit to examine the individual human footprint as a function of consumption and food diet.
What are the Elements of the Footprint Family?
Since the concept of footprint was first introduced, a footprint literature has been developed after the environmental footprint. There are many different concepts within this literature.
What is Ecological Footprint?
The ecological footprint was first developed by Wackernagel and Rees in 1996. Today, it provides a measurement of the land allocated as a resource for waste intake. The ecological footprint has components within itself.
- The first component of the ecological footprint is the measurement of land used for fishing, pasture, cultivation, settlement, or forestry. Another component is the measurement of the land required for waste reception and the forest land required to sequester carbon dioxide, which is usually emitted after the burning of fossil fuels.
- When measuring the ecological footprint, the measurement is provided in hectares. At this point, while actual hectares are considered, a weighted result is obtained by comparing the biological productivity of each of these hectares with the world average biological productivity per hectare. In other words, the ecological footprint shows the use of bio-productive land in hectares. In this context, it is also referred to as land footprint at some points.
What is Water Footprint?
Within the footprint family, water footprint was introduced in 2002. Within the framework of this concept, while measuring the use of fresh water, fresh water is considered as a resource and its use for assimilating wastes is also taken into consideration. Within the framework of the water footprint, there are 3 components: green, blue and gray water footprint.
- The concept of green water footprint refers to how much rainwater, the so-called green water source, is used.
- The concept called blue water footprint indicates the amount of groundwater and surface water use, which are referred to as blue water sources.
- The concept of gray water footprint refers to the amount of water required for the assimilation of water polluted because of human activities against freshwater bodies.
The term consumption in the definitions refers to how much water is lost from the existing groundwater body within a catchment area. For example, if water reaches another catchment area or the sea after evaporating in the area where it is located, or if it is used for a product, water loss, i.e. consumption, occurs.
What is Carbon Footprint?
Within the footprint family, the concept of carbon footprint or climate footprint was developed in 2005. This concept measures the release of greenhouse gases into the atmosphere and expresses them in carbon dioxide equivalents. Because in addition to carbon dioxide, greenhouse gases such as methane and nitrous oxide are also included in the gases released to the world. Considering their global warming potential after the emission of such greenhouse gases, the emission rates of these gases are converted into carbon dioxide equivalents.
What is Material Footprint?
Another footprint family member, the material footprint focuses on mining raw materials. Within this focus, it has recently been developed to measure resource allocation. Recently, footprints of phosphorus and nitrogen have also been developed in this context. While phosphorus and nitrogen may seem very similar, they are actually quite different as one is considered for resource use measurement and the other for emissions measurement.
Phosphorus/Nitrogen footprint are 2 new concepts developed for material footprint. One of them, the phosphorus footprint refers to phosphorus mining, which is a very low resource. The other concept, the nitrogen footprint, refers to the environmental damage caused by reactive nitrogen, which is a critical pollutant that causes eutrophication in lakes, seas, and rivers, often combined with risky ecological damage.
What is the Chemical Footprint?
One of the important recommendations in the footprint family is the chemical footprint, which should be used to measure the release of changing chemical factors into the environment, water, soil or air. For example, different chemical loads reaching a body of water are tracked in a weighted manner in the gray water footprint, while the changing chemicals at this point are calculated in weighted proportions, taking into account their potential harm.
As seen in the footprint examples, there is no principal limit. In other words, a footprint can be defined by considering any specific environmental concern, with the concept of environmental footprint at the top. However, there is a commonality for each footprint as mentioned. Because in each footprint, resource use and/or emission measurements are made within the scope of supply chains. Thus, the use of resources and the emissions that occur after certain stages in the production of certain products can be attributed to consumers and end products.
Comparison of Consumption and Production Footprint
Footprint calculations mainly consider the footprint resulting from production processes or human activities. In this case, if the footprint rates for each point are known, the footprint of a product, a consumer or a producer, or a geographical footprint can be estimated.
- The footprint for a product is obtained by summing the footprints at each of the production stages.
- The footprint for a consumer is obtained by summing the footprints on all goods and services consumed.
- The footprint of a geography, i.e. the footprint of the inhabitants of a country or city in a region, is obtained by summing the footprints of community members.
- To obtain the footprint for global consumption, the footprint of global production is calculated. Because both are equal to each other. At this point, both the global consumption footprint and the global production footprint are obtained by adding the footprints of human activities.
Brief History of the Water Footprint Idea
In 2002, while the idea of water footprint was being developed and advanced, in the last period of the same year some ideas and some initial estimates about the water footprint of nations were developed and presented internationally. In this context, water footprint was introduced as a concept developed to show how much water a person or a country’s individuals use against the background of all goods and services consumed. In the calculation of the total water footprint for a nation, it was recognized as an important indicator of the nation in the international struggle.
While it was initially thought to analyze indirect water use by considering the individual footprint for global water resources, doubts were later raised that this was unreasonable. In this context, the need to allocate actual water use, not indirect water use, was expressed.
After the emerging ideas, it became more important to analyze the geopolitical and international dimensions of water resource allocation, especially considering the fact that water is not evenly distributed around the world and that water is an important resource.
Even today, there are many different criticisms of both the water footprint and the concept of virtual water trade. However, while a large area is being achieved in both points, different studies and more practical use cases have emerged. As a result, from the first steps taken with a very simple concept to the present day, water use rates, water scarcity and water pollution; all steps that occur with production, trade or human consumption have led to the concept of Water Footprint Assessment (WFA).
What is the WFN Water Footprint Network?
The WFN is an interdisciplinary and integrative discipline related to academic papers in environmental science or water resources publications. In the context of its interdisciplinary role, the concept primarily brings environmental thinking, i.e. footprint and supply chain thinking, to the water resources community. At the other point, it brings water resources thinking, i.e. water allocation, water scarcity and water efficiency, to the environmental sciences community. In this way, it provides a bridge between the communities.
The History of Green, Blue and Gray Concepts in Water Footprint
The water footprint is essentially a measurement of the use and degradation of freshwater. As mentioned earlier, the green water footprint measures rainwater consumption, the blue water footprint measures surface water and groundwater consumption, and the gray water footprint measures the volume of water needed to assimilate freshwater pollutants.
When water footprint research first started, the target was consumptive water use. From the first point on, the scope of green and blue water consumption was also expressed in water consumption. In fact, in the models applied, these components were presented as a sum since they could not be clearly distinguished and used. Then, in 2000, the green-blue water terminology study by Falkenmark was taken into consideration in order to bring blue water to a broader point in the perspective of water management, and thus, green water consumption was consciously included in the water footprint measurement.
The first article in the literature, written by Chapagain, evaluated the green and blue water footprint of a product separately. Even though the concept of gray water footprint was not directly used in this article, a definition of this concept was made, and a definition was made as the “volume of navigational water” that would be needed to absorb a pollutant load.
The green, blue and gray water footprint was first presented in a coherent framework by Hoekstra and Chapagain in 2008. In 2011, Hoekstra even further refined the definition of the gray water footprint by considering the natural concentrations of substances in a water body. This reduced its capacity to absorb additional anthropologically derived loads when maximum allowable concentrations are considered.
The first graywater footprint studies only considered pollution through nitrogen. Today, the concept has been broadened to include a wide range of parameters such as metals, food, pharmaceuticals, dissolved solids and pesticides. In fact, even though some studies have created a distinction between different types of blue water footprint by considering the source of water (renewable groundwater, capillary upwelling, surface water or fossil groundwater), this can be further extended within the framework of the data. This is because different potential impacts can be seen in different shades for the blue water footprint.
What are the 4 Key Ideas of the WFA Area?
There are 4 basic ideas within the WFA area, which is called water footprint assessment.
- Under the first idea, freshwater is adopted as a global resource. This is because sometimes people have the chance to use a freshwater resource elsewhere indirectly through virtual water trade. Today, while the global economy drives local water-related movements, there are no incentives for sustainable water use. In this case, countries can “externalize” the water footprint of their consumption to different parts of the world without incurring any costs.
- The second idea uses the term limitation for freshwater replenishment rates. Accordingly, the evolution of consumption, production and trade patterns related to limitations should be examined.
- In the third idea, by thinking about supply chains and product life cycles, consumption impacts and the use of natural resources can be understood. Through the water cycle and water footprint, supply chain thinking is included, which was previously absent in resource management. Through this thinking, sustainable water use can be considered in the context of both companies and end consumers.
- The fourth idea addresses the scope of freshwater use and scarcity, considering green and blue water consumption and water pollution. While blue water supply is often considered in water management, often the availability of green water is not considered, and water scarcity and water pollution concerns are not integrated into these calculations.
In the traditional framework, engineers have not focused enough on using groundwater and surface water, so-called blue water. This is because rainwater, or green water, plays the most important role for agricultural production. But for a comprehensive study of water consumption in agriculture, both green and blue water consumption should be examined. In addition, when allocating freshwater, not only water consumption but also water pollution should be considered.
Moving from the concept to the point of analysis, the first stage of development in water footprint measurements focused on the water footprints of products, virtual water trade in terms of product trade, and national water consumption footprints. Later, in 2007, a broader scope was achieved as companies and producers started to explore the concept of water footprint. With these developments, basically;
- All water footprints
- Finished water footprints
- Personal levels or community levels
- Left footprint of manufacturing in a defined geography
- Water footprints in company operations and the supply chain made it possible to quantify water footprints.
As the scope expanded, while collecting water footprint values for products, an item related to the water consumption per unit of the product was introduced in order to obtain a more consistent result. Thanks to this item, the terminology of “virtual water content” or “specific water demand” was changed to the water footprint of a product.
Final Point
As the WFA was renewed, new perspectives for water management were added in this framework. At this point, there are new perspectives on water, water pollution and scarcity, and water management.
In the new perspective for water, while a global dimension has been achieved in terms of types of use, water pollution and water scarcity, it has started to analyze what can be done beyond the local in terms of water use sustainability and equity. Because while water problems were previously thought to be only local, today there is a national perspective.
Thanks to WFA, the biggest factor behind water pollution and scarcity problems can be analyzed. This factor is, of course, consumption. In this sense, water demand management should reduce the need for water per user.
The new focus in water management has evolved from the traditional focus on governments managing their own water resources to supply chain thinking. In other words, consumers, companies, and investors that are not connected to the water basin are now included in the analysis. WFA companies in focus;
- From gross to net use of water
- From process stages to supply stage
- From the existence of a guaranteed “right to abstraction” to the assessment of true sustainability in water consumption and
- From the point of meeting “emission permits”, it depends on the assessment of how much real contribution the business makes to the environment.
