The water we eat
Water. The basis of life as we know it. Most ancient civilizations, such as the Chinese, Mesopotamian, Egyptian, or the Indus Valley, developed near sources of abundant water. 60% of the human body is water. And it seems like we are surrounded by it. Covering more than 70% of the Earth’s surface, our planet should probably be called the “Ocean” instead of the “Earth”. But less than 1% of the Earth’s water is responsible for sustaining all life on Earth. On top of it, that 1% is not evenly distributed across the globe. Most regions that are densely populated usually do not have enough water to meet the water demand of people living there. In fact, four billion people face extreme water scarcity for at least one month in a year. So, usable water is in fact a limited resource, and we currently are not doing a very good job of using it judiciously. Scientists believe that humans have already appropriated a quarter of the total fresh water available on land surface that all plants and animals depend on for survival.
Now the question is, what are the most water-intensive activities in our daily life that are contributing to humanity’s large water footprint? Domestic use, as a whole, accounts for just 10% of humanity’s water demand. Industrial processes are responsible for another 20%. The remaining 70%, the biggest fraction, is used in agriculture. Three out of four litres of water you consume, are hidden in your food. Globally, agricultural production uses more than 8300 km³ of precious water, each year. It is such a large amount that, if all of that were collected at one place, it would create the fourth largest lake by volume in the world. For a comparison closer to home, that is equivalent to 3.3 billion Olympic sized swimming pools.
How DOES our food production consume so much water?! To start with, crops need a lot of water to grow. 1 kg lettuce needs 250 L of water. 1 kg wheat needs more than 1800 litres. Animal products are a whole different story; for instance, beef production requires over 15000 L per kg. And our beverages are water guzzlers too; one cup of coffee needs one thousand cups of water. Of course, these numbers are contextual viz-a-viz rainfed versus irrigated agriculture, but are a good metric of our water demand. When added up, it shows that an average person, “eats” over 3000 L water per day from food alone. And that is just the global average. People consuming diets rich in animal products have significantly higher footprint than their vegetarian counterparts.
Solving the agricultural water crisis requires a nuanced systems approach that is often lacking when decisions and policies are made. For example, to reduce the water consumption on irrigated agricultural fields, governments and policymakers often promote efficient irrigation practices like sprinkler and drip irrigation to produce “more crop per drop”. While this could work in certain cases, it is also possible that water saved at farm level does not necessarily translate into water saved at basin level (a recent article explains this phenomenon really well). That is because what constitutes as “water lost” from one farmer’s field can be used for irrigation by farmers downstream. Improved irrigation techniques might sometimes even exacerbate water scarcity by enabling farmers to switch to more water-intensive crops. All this is to say that water scarcity solutions need a multi-dimensional approach that factors in all dependencies in the system.
At the other end of the spectrum, is there anything we as individual consumers can do to help mitigate the water crisis? Obviously this problem is too big to be affected by a single person, right? I recently attended a talk by Dr. Paul Slovic where he discussed the concept of “pseudo-inefficacy”: that all too common feeling of helplessness when faced by problems that we feel are beyond our individual capacity to solve. But we need to remind ourselves that every small action counts; as consumers, can just start by reducing their food waste! One-third of the food leaving farms is wasted or thrown away. As consumers, reducing food waste is the low hanging fruit (pun intended) that all of us can help in picking. You can also contribute by changing your food preferences. Maybe reduce beef consumption. The next time you are at a barbecue, substitute that steak with pork or chicken, and you would be actively contributing towards reducing humanity’s water footprint. To go a step further, replacing a part of our meat consumption with vegetarian food can go a long way. For the skeptics out there who still doubt the efficacy of individual actions, simply being sentient (and starting a dialogue) about the environmental impact of everyday activities like eating can help support policies, programs, and actions to scale up these individual efforts.
Water is one of the primary enablers of life. It is the first thing space scientists look for in their search for extra-terrestrial life. Back home on the Earth, we haven’t treated it as well as it should have been. Fortunately, the time is not up, and each one of us still has the power to contribute towards making sure the future generations can enjoy the same comforts we enjoy today.
