Let us begin with a definition. Water scarcity occurs in a given region when the demand for freshwater is higher than the supply. Water on our planet is a renewable resource, yet water scarcity remains an issue in some regions due to a range of factors, all of which are social constructs that rely on our ability to effectively interact with the water cycle. These may include the physical lack of a sufficient regional source, underdeveloped infrastructure for water storage and distribution, or the inability to provide adequate water services such as treatment and sewerage.
The global population is growing, so much so that we are estimated to number over 9 billion by the year 2050. This graphic from Scientific American shows how the UN’s 2014 projections compare to our old ones from 2001. If you thought that the growth rate that gets us there is big enough, think again. According to the UNFAO, the global rate of water use has grown to more than twice this over the 20th century, and it isn’t stopping.
To add to this effect of population growth, we have climate change. Regardless of whether everyone reading regards climate change as at least in part attributable to human interference, the world is getting warmer and this will affect the hydrological cycle. The UN Intergovernmental Panel on Climate Change (IPCC) predicts a 0.3 – 4.8ºC rise in the global temperature by the end of the 21st century.
Unfortunately, the world has not really woken up to the reality of what we are going to face in terms of the crises as far as water is concerned.
— IPCC Chair, Rajendra Pachauri
For those in need of some empirical proof of climate change, the figure to the left shows the observed global annual average surface temperature changes between 1901 and 2012. This data from the IPCC’s 2014 Climate Change study (direct link) shows that some regions have experienced a rise in up to 2ºC over the last century.
So that was what we’ve actually observed so far, and the figure below shows two projected scenarios of global warming for the last 20 years of the 21st century. They represent two different greenhouse gas emission scenarios with Representative Concentration Pathways (RCPs) of either 2.6 or 8.5 — 2.6 essentially showing what happens if we significantly reduce our emissions and 8.5 if we don’t.
As you can see, the worst case scenario is that the majority of regional land surface temperatures rise by at least 4ºC and this will be felt particularly hard if our staple crop species fail to adapt to the change in time. The driest parts of the world are going to be most at risk with the rise of freak droughts in countries such as India — India also happens to be one of the most densely populated regions on earth.
Water scarcity not only affects the domestic supply, but is extremely detrimental to agriculture, and consequently, to the food security of these countries that rely so heavily on their crops. As global population and temperatures continue to rise, competition for water will intensify, not just between individuals and nations, but between the different water-using sectors. So what can be done?
There are a whole host of organisations and charities designed to directly combat water scarcity in the most affected regions. They often focus on improving infrastructure for water storage and distribution, or on the development of simple water treatment methods for rural populations. But how can your average Westerner help, other than through monetary donations? Most of us will have been brought up not to unnecessarily waste water and some of us may even make a conscious effort to minimise our water footprints. Resources such as Water – Use it Wisely are put in place to educate us on ways of domestically saving water. Some examples from their site are shown below.
However, here’s the kicker…
Domestic water use only accounts for around 10% of what we refer to as global water withdrawal (that is, withdrawal from the natural hydrological cycle). What then uses up all our freshwater? Unsurprisingly, agriculture.
The UN estimates that agriculture is responsible for 70% of our global freshwater usage, but it is also the sector with the most potential for reducing the total. The problem is that with the projected 9.6 billion mouths to feed by 2050 and increasing globalisation in developing countries, more and more people are demanding a higher quality and quantity of more diverse foods; especially more meat. The average global daily individual caloric intake is estimated to rise from 2,650 to 3,000 kcal/person/day by 2050 (Bruinsma, 2009). So not only are we going to be many more people to feed, we are each going to consume more food, on average, than we do currently. In order to match the demand, supply of beef, for example, will need to double.
As we have already mentioned in this post, beef is extremely inefficient in terms of the amount of food you get for your water, feed or land use input. To reiterate, Pimentel and colleagues (2004) found that per 1kg of meat produced, chickens need 2,300 litres of water, pigs need 3,500, and beef cattle need 22,000. The UN knows this is unsustainable — the prime reason why they have been so enthusiastically advocating insects as a food source. Mealworms, for example, obtain all of the water they need from their food so they effectively require no additional water to produce the same amount of meat.
From Saving Water to Improving Food Security
There’s a great article in National Geographic by Jonathan Foley, called “A Five-Step Plan to Feed the World“. He outlines the steps we need to take in order to successfully meet the rising demand for food over the next few decades without completely destroying our planet’s resources. But how might insect farming fit into the plan?
According to the UNFAO, agricultural land takes up a third of the world’s land surface. Of this agricultural land, only around 30% is actually used to grow crops for human consumption — the other 70% is designated as permanent pasture for livestock (FAOSTAT data on land use). This has already been responsible for the destruction of entire ecosystems and is continuing to eat into areas of high biodiversity, some of which, like the Amazon rainforest, we rely on to curtail the effects of climate change. Such is agriculture’s footprint. We can simply no longer expect to feed the growing masses through any more agricultural expansion.
Now imagine a scenario where the meat we produce, pound for pound, takes up only a tiny area of the land currently in use. Include in this ideal world, if you will, the capacity for every household to sustainably farm their own source of meat without the need for expansive pastures or expensive machinery. This is all within the realm of insect farming. Here’s that land use figure again to illustrate the point (Oonincx and de Boer, 2012). The graph shows the amount of land required to produce 1kg of animal protein from each form of livestock.
Both commercial and organic farming have come a long way in the last few decades — farmers are beginning to get smart with their water and nutrient use, tailoring their crop treatments to their crop and soil type. This is great news for arable farming, but again, the other 70% of agricultural land is for livestock and the differences in energy conversion efficiency between cows and insects are just too large to ignore. By weight, only 4% of cattle feed is converted into edible meat, but crickets manage to convert 47% of plant biomass into food we can eat (Smil, 2002; Collavo et al., 2005). When you then consider water and land use as additional factors, insects win in resource efficiency by miles.
As far as edible insects go, this is where the big challenge lies. Convincing the West of all the benefits is one thing, but what people really need to know is that many insects actually taste good and are just as healthy, if not more so, than beef and other more traditional meats. Over 2 billion people from 80% of the world’s countries eat insects already — in fact the rest of us do too, albeit accidentally through processed foods — we just need to take the first brave step. Once you intentionally try insects a couple of times, you begin to realise that they are just another food.
According to Foley’s article, a staggering 50% of global food, by weight, is wasted before it is consumed, either domestically by throwing out leftovers or commercially due to insufficient storage and transportation methods. Consider the fact that insects can be grown in urban environments and every household could theoretically have their own farm. This may be unrealistic in the near future, but it definitely would minimise the food wastage that arises from lengthy periods between harvest and consumption. Not only that, but a lot of kitchen waste could be fed directly to your insects anyway, reducing waste from leftovers.
For the ecologically-minded among us, saving water often means limiting our domestic use or at least being careful not to waste it unnecessarily. Globally however, we can make much more of a difference through our food choices; through minimising our reliance on red meat — after all, supply will always try to find a way to meet demand. Through these choices, water conservation itself is also related to the fate of our other resources like land and food crop abundance. The rise of entomophagy is a promising indicator that things could be changing for the better. What the world needs now, as ever, is continued advocation of these kinds of endevours, aiming to increase the sustainability of our life on this planet.
Bruinsma, J. (2009). The resource outlook to 2050. In Expert meeting on how to feed the world,2050: 1-33.
Collavo, A., Glew, R.H., Huang, Y.S., Chuang, L.T., Bosse, R. & Paoletti, M.G. (2005). House cricket small-scale farming. In M.G. Paoletti, ed., Ecological implications of minilivestock: potential of insects, rodents, frogs and snails. pp. 519–544. New Hampshire, Science Publishers.
FAO (2012). Water & poverty, an issue of life & livelihoods.
Gerland, P., Raftery, A. E., Ševčíková, H., Li, N., Gu, D., Spoorenberg, T., … & Wilmoth, J.(2014). World population stabilization unlikely this century. Science, 346(6206), 234-237.
IPCC (2014). Climate change 2014: impacts, adaptation, and vulnerability. Vol. 1.
Lutz, W., Sanderson, W., & Scherbov, S. (2001). The end of world population growth. Nature,412(6846), 543-545.
Oonincx, D.G.A.B. & de Boer, I.J.M. (2012). Environmental impact of the production of mealworms as a protein source for humans: a life cycle assessment. PLoS One, 7(12): e51145.
Pimentel, D., Berger, B., Filiberto, D., Newton, M., Wolfe, B., Karabinakis, E., Clark, S., Poon, E., Abbett, E. & Nandagopal, S. (2004). Water resources: agricultural and environmental issues.BioScience, 54: 909–918.
Smil, V. (2002). Worldwide transformation of diets, burdens of meat production and opportunities for novel food proteins. Enzyme and Microbial Technology, 30: 305–311.