Water Footprint

I just read one of the many articles that appear at regular intervals telling us how much water it takes to produce beef. I thought it would be interesting to follow the story back to the source: that took me to this Unesco paper downloadable at UNESCO water footprint, from which the article had extrapolated some figures based on this quote:

"The production of one kilogram of beef requires 15 thousand litres of water (93% green, 4% blue, 3% grey water footprint). There is a huge variation around this global average. The precise footprint of a piece of beef depends on factors such as the type of production system and the composition and origin of the feed of the cow."

Take note of that 93% green figure (13,950 litres, leaving 1,050 litres in the blue and grey parts); Green is defined as rainwater in so far as it does not become run-off.

The logic of including rainwater in a generalised product footprint is elusive. The water cycle is an essential part of the natural environment, not something that we control directly. The role of land on which precipitation falls is key in determining how available water is to us afterwards – management is a determining factor in how much runs off, with accompanying sediment and thus influences the replenishment of aquifers, river flows etc. Slowing the movement of water to the sea, and reducing evaporation both contribute to better water availability. The implication made by counting green water as a cost is that there is no ecosystem benefit to be gained through land management strategies. Using this logic would suggest that forests have a very high water footprint indeed; consider the amount of rain that must fall to produce any timber product, and yet no one would seriously consider this methodology a valid argument against the existence of forests. Well-managed rangelands and pastures have a hugely important positive role to play in the water cycle – given their extent, this ecosystem service they provide is second only to forests; on condition that they are managed well.

Now remember that 70% of the land we use for agriculture is grazing land, simply because it is land not suited to other purposes - it cannot economically produce crops that humans can consume directly. If we choose not to consume ruminant products, is it realistic to think that we can replace all of them with food from the other 30% of productive land without having a negative environmental, social or economic impact? 

Consider the biodiversity benefits of maintaining grazing lands, particularly native rangelands (I recognise that this value can and is regularly eroded depending on management), as well as the benefit of sequestering carbon in the soil (again, not automatically the case, but it is in well managed grazing systems).

If changing climate is forced by excessive carbon in the atmosphere, and one of the effects of this change is increased variability and severity of weather events, including droughts and flooding, should we not be looking hard for ways of sequestering carbon to a) remove it from the atmosphere to mitigate its negative effects there, b) help retain soil moisture for longer in dry spells and c) to soak up more water when floods come? The soil is the largest carbon sink available to us; so why not look at the problem from two sides - not enough carbon in the soil ≈ too much in the atmosphere.

There are hundreds of millions of acres of degraded rangelands and pasture in the world - mostly through poor grazing management (often due to a failure to allow rangelands or pasture time to recover following grazing, or due to over resting; i.e. the problem is thus frequently one of timing, not of animal numbers). Restoring rangelands would have multiple benefits; in sequestering billions of tonnes of carbon, putting it back in the soil where it belongs and thus increasing the moisture retention capacity to mitigate flooding, increase resilience to drought and enhance productivity. Slowing down the water cycle by storing water in the soil is beneficial, not least due to the fact that water vapour in the atmosphere amplifies warming. To restore rangelands, we need to restart the carbon flows, and the most effective way to do this is by managing grazing animals well. This will also deliver high quality protein from  animal products - should we consider those products to have a large water footprint? Or are they part of providing ecosystem services?

Now to the biodiversity side of the equation; there may be some who consider that returning grazing lands to "the wild" would be a suitable alternative and just as beneficial to the planet. There are a few obstacles. A lot of people live in those areas today, and would not take kindly to finding that they are suddenly live in a wildlife preserve. Secondly the teaming hordes of wildlife that once roamed those plains are no longer there, and neither are the carnivores that hunt them. Without grazing, rangelands turn to desert - the carbon flows grind to a halt, and all of the benefits mentioned above do not transpire, the opposite does; plants oxidise, carbon is lost and bare ground reflects solar radiation forcing warming.

Blue water is consumed, e.g. directly by animals, or in producing crops fed to animals, and grey is polluted water, defined as the volume of freshwater required to assimilate it. Let us look at those figures; these include water that the animal drank - very little of which stayed in the animal of course, it was returned to the soil, enriched as urine and dung as a short and positive loop in the water cycle - and water that was used to grow crops. In many cases today, that crop would be corn, and in increasing amounts that corn is first used to produce ethanol and then fed to cattle (being too wet to be used to feed monogastrics). Is all of that crop water attributed to beef, or does some now get attributed to "green" flexfuel cars? There is also the matter of buffering of grain supplies - in years of larger surpluses, grain can be diverted to livestock production to tranform it into higher value products and in times of scarcity less grain is used in the livestock industry, leaving enough for the primary uses. This buffer may not work perfectly, and more grain than strictly necessary may end up being fed to livestock, but there are great efficiency trade offs to be made in finishing livestock on a partial grain diet, meaning a lower supporting herd, and thus lower emissions per kg of product.

Blue water also includes the water used in the processing lines, and this is an area where best in class facilities have demonstrated both huge water savings and the ability through water treatment, to return water safely to the environment (rivers, ground water); these need to be adopted more widely and should be encouraged.

Looking at things in a little more detail often reveals a complexity that gives the lie to the simple fixes we are so often presented with. Simple statements often suit people with a ideological agenda, who have already decided what they think is best as well as what is bad, and who look for simple "facts" to support their position.

Overconsumption = wastage; that is a fairly simple concept to grasp - maybe that is the one we should focus on, in terms of everything we consume, rather than pushing simple ideologies as if they were solutions to complex problems.