SELECTING THE APPROPRIATE TOOL TO CALCULATE THE WATER FOOTPRINT OF BEEF PRODUCTION
September 8, 2017
Water may be renewable, but using it at too fast a rate or in a way that pollutes water sources can deplete this precious natural resource. Yet water is essential for producing high quality food safely and sustainably.
The livestock industry is often heavily criticised for the amount of water that is used to produce meat. However, calculating the water footprint of producing meat, particularly from cattle and other ruminants, is a complex calculation that can involve up to three distinct streams of water.
A recent scientific review paper published in the Journal of Animal Science by a team of international researchers that included Getahun Legesse, Kim Ominski and Emma McGeough with the National Centre for Livestock and the Environment at the University of Manitoba and Tim McAllister, Karen Beauchemin, Roland Kroebel and Marcos Cordeiro of AAFC-Lethbridge shows that the size of the beef footprint really depends on how it was calculated.
More than one assessment tool
According to their review, there are different methods available for assessing water use in livestock production systems, each with its own set of benefits and limitations. Traditionally these assessments were conducted on the basis of productivity, which included having access to sufficient water of suitable quality to meet the direct needs of the cattle herd. More recent approaches also assess the environmental impact of production, quantifying the potential detrimental impacts on water quality and availability.
The most common methods are Water Footprint Assessment (WFA) and Life Cycle Assessment (LCA). These techniques include livestock-related product outputs plus other benefits or services relative to the amount of water consumed or impacted in order to produce these products.
The WFA method is widely used for national, regional and global assessments of animal products and production systems. It attempts to measure the volume of freshwater consumed or polluted during the production process.
LCA is the most popular approach for determining the impact of a product on water and other environmental indicators, and is capable of determining water use/impacts along any point of the value chain from farm to table. LCA is particularly well-suited for assessments at a local scale - the area where production occurs - so that impacts on water scarcity, water depletion, and human and ecosystem health can be properly accounted for.
Selecting the right tool for the job
Their review showed that estimates of water use for ruminant production can vary widely, depending on the method, scope and scale employed. For example, published global estimates of water use for beef production range from less than a thousand to more than one hundred thousand litres per kilogram of beef.
The main challenge in accurately assessing water use lies in selecting an approach that adequately captures the key water inputs, product outputs and potential water impacts for the cattle production system and land area of interest, without being overly complicated or too simplistic.
Since water availability and production practices vary with time and place, it may also be useful to assess environmental impacts on a relative basis at a local scale, comparing alternative land uses and considering environmental impacts beyond water alone. The evaluation and development of appropriate strategies to reduce water use should also take into account external influences such as political, cultural and socio-economic realities. The benefit of using land to produce livestock compared to growing food crops or other uses may otherwise not be apparent.
For example, in hot, water-stressed areas or where seasonal water availability can change dramatically, annual crop production might be too unpredictable, but the land might be suitable for grazing livestock. Similarly, draining a wetland for crop production would have a greater negative impact than allowing cattle to periodically graze this area.
Next step - Water footprint of Canada’s beef herd
Why the lengthy review of methodologies? The Canadian team is using this information to conduct a comparison of the water use intensity associated with Canadian beef production in 2011 compared with 1981. Selecting the appropriate assessment tool could mean the difference between an accurate representation of actual water use and impacts of Canada’s beef herd or one that is not representative of reality on the ground.
Financial support for this project provided by the Beef Cattle Research Council and Agriculture and Agri-Food Canada through the Beef Cluster Project.
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