In the north-western Tabuk province of Saudi Arabia, armies of diggers carve into the arid desert as they attempt to excavate a 170-kilometre line. This project is part of what is called Neom, ‘The Future of Civilization’, and emerges from ‘The Saudi Vision”, a plan to reduce Saudi Arabia’s dependence on oil and diversify its economy by developing its public-service sector. The project’s estimated cost exceeds $500 billion, but this is the least of Saudi Arabia’s worries since they have already started over 17 megaprojects which cost a staggering $7.5 trillion in total. However, the biggest issue that Saudi Arabia will have to face, along with incentivizing 10 million people to live in a colossal mirror in the middle of a desert, will be finding enough water to keep them alive.

A human can only last three days without water, and we require two litres a day to survive. If we apply this to Neom, we unravel the logistical nightmare that its project designers will be faced with. They will need to produce over 20 million litres to just keep these people alive, and when we think about how much water the average person requires for their basic needs in the developed world, the figure of 500 litres daily seems unreachable. Desalination may be the first thought to come to mind, but in its current form, it is simply unsustainable. For every cubic metre of salt water, the theoretical minimum amount of energy needed to desalinate would be 0.86 kWh of energy; however, present-day desalination plants use up to 5 to 26 times more energy than this. This is because desalination involves forcing water at extremely high pressure through little holes which then capture the dissolved salt particulates and let the water molecules through. As we attempt to transition to renewable energy and sustainable energy consumption, processes such as desalination will have to be innovated to make them more environmentally friendly.

Fortunately, we have already found various solutions to these issues, which have been best adopted by Singapore. Singapore’s water resource infrastructure is crucial due to its limited land and lack of natural aquifers and lakes, despite receiving an average of 2,400 mm of rainfall annually. Singapore employs what it has named the “Four National Taps,” a far from foolproof but largely successful program. The programme commenced in 1962 and currently includes the collection of water in artificial reservoirs, importing water from Malaysia, producing NEWater, and desalinating seawater. The most successful of these “taps” is NEWater, which Singapore has used to combat its water scarcity and currently fulfils 40% of the country’s water needs. This 17-year-old water reclamation initiative utilises a four-stage treatment process where the wastewater passes through sedimentation, membrane filtration, and ultraviolet radiation. The revolutionary processes make it both more cost-effective and more energy-efficient than desalination. The only issue that the government has had to deal with is the source of most problems that humanity faces, which is solely down to irrational human behaviour.

For many, the prospect of using recycled sewage water seems disgusting, and Singapore has been subject to public resistance over its usage in the public supply of water. This resistance is far from logical because the levels of toxic materials present in the water produced by NEWater are far below the rates coming out of regular tap water, which are full of heavy metals that are leached off old lead pipes. Singapore will continue to invest in NEWater, raising public awareness regarding water conservation, and has just approved the construction of a plant that will cost $125 million. While the targeted contribution of desalinated water to Singapore’s water will stay the same from now to 2060, the Singapore government aims for a 15% increase in NEWater’s contribution in the same period. Although the method is cheaper than desalination, membrane technology continues to be expensive, and we will need to turn to nature for a solution.

I was presented with some of these solutions while speaking to Dr Yerby, a fellow of the University of Pennsylvania. I was introduced to the idea of Biomimicry and the “Blue economy”. This refers to the sustainable use of the marine environment and is often discussed in the context of international development, emphasising a sustainable approach to managing coastal resources. The concept encompasses a variety of economic sectors, including traditional areas like fisheries, but also includes emerging fields such as renewable energy and marine ecosystem services. Using Biomimicry, the process of emulating processes found in nature, we could not only solve our water shortage, but also acquire a treasure trove of raw metals which our economies have become ever more dependent on.

Dr Yerby’s research focuses on this very Biomimicry by understanding how we can mimic what biology does in our cell transportation membranes and then use these same principles to mine salt water for resources and dissolved metals. The body does so more precisely than any desalination machine and only requires temperatures of 37C, which expends a minimal amount of energy. This new technology enables us to separate dissolved salts not only from the water but also from each other, which is done by having the solution pass through multiple of these membranes, where the pH of the solution is constantly adjusted at each stage of the process. This would enable different metal ions to be pulled out of the solution, allowing one to mine different metals with much greater accuracy.

Dr Yerby also detailed the current issues with the technology, which are finding the different pH levels where the metal ions have a propensity to come out of solution as well as the initial set-up costs of the process. Each of the membranes costs over $50,000 to make, and in their current form, they lack the durability to make this a worthwhile investment. Furthermore, the technology to make the holes sufficiently small enough is yet to be discovered. For example, a gamma ray laser would be needed, but this requires a global effort and billions of dollars to develop. However, the opportunities available when the technology reaches its final form are endless. It will allow companies to have access to all the dissolved metal ions, many of which are rare earth metals, in seawater.

The rare earth metals present in the sea are of great strategic importance for all nations because they are used in motherboards ranging from home appliances to military vehicles. Currently, countries that are rich in these rare earth metals, such as the US, export them to China, which controls 95% of global refining of ‘technology’ metals. This is largely due to it being an arduous six-month-long process, but also because no other developed country can be asked to deal with the toxic sludge that is formed as a by-product of refining. Yet, in 2010, amid tensions between China and Japan, China decided that it would impose limits on rare-earth metal exports to Japan. They cut exports to Japan, sending shockwaves throughout the developed world as they soon became aware of the control that China had, and they decided that they should start building infrastructure to refine the metals themselves.

The use of biomimetics would completely revolutionise how we view resource extraction and would limit China’s control over rare-earth metals. This membrane filtration system could be placed anywhere in the sea and start ‘mining’ for metals dissolved in the water and mud on the seabed. It could even be used for the clean-up of old mining sites in countries such as the US, where, up until the 1970s. mine operators could mine for valuable hard rock minerals —i.e., gold or copper— and then abandon the land. On the lands they oversee, federal agencies have identified about 140,000 of these hardrock mines, including unsecured tunnels and toxic waste piles. Hundreds of thousands more likely exist. Remedies include sealing tunnels, but the more sustainable pathway would be to use membrane technology to clean up the sites.

The US government currently pays companies to take over these polluted areas and clean them up. You can imagine the business opportunity that then comes to mind, where you could start a business and be paid by the US government to process raw materials, in this case, the polluted mud and water around mines. Then you could pass them through your membrane filtration system to both clean the water and produce metals that could then be sold off.  A business venture where the only real costs are the initial set-up costs and then small variable ones such as electricity to keep the machine running and labour costs, which will be minor because the process is almost entirely automated. It would be able to produce profits while also cleaning the polluted bodies of water in a nation, an idea that just seems too good to be true in the ‘green revolution’ of today.

In its current state, this technology is simply too unsustainable, but its future development is likely to cause a geopolitical struggle between nations as they attempt to assert control over bodies of water. Much like the struggle for oil, water may also become a precious commodity, not just because it keeps us alive but because it hides a treasure trove of metals dissolved in it, just waiting to be fished out.  At the same time, the scarcity of water, a current socioeconomic issue that only affects a select few nations, may also lead to an almost entirely different geopolitical struggle over water. As global temperatures surge, fresh water will become less obtainable, with irregular rain and increased droughts. Water may become more important than gold as we struggle to supply enough of it to satisfy our increasing needs. Nonetheless, only the future can reveal to us whether we will be fighting wars over water like our predecessors did in the 16^th century and whether it will become the precious commodity of tomorrow.