Reviving Water: Sustainable Solutions for a Scarcity-Stricken Future

Oceans make us feel small. How can human beings affect something so mysterious, so powerful, so vast? This attitude, unfortunately, is one of the reasons behind the current failure to ensure a sustainable future for the world’s water systems. Yet the very opposite is true: even as individuals – and certainly as societies – we can and already do impact our oceans and other water sources. And because these are so intricately interconnected, this affects the whole of our blue planet. 

Currently, human activity mostly creates problems. But solutions to these problems exist, says Yannick Ouaknine, Head of Sustainability Research at Bernstein, a joint venture between Societe Generale and AllianceBernstein. “If we manage to raise awareness, as we have done with climate change,” he argues, “and if we then act collectively, we can start to tackle the issues.”    

Raising awareness starts with understanding the context. While 70% of the Earth is covered by water, less than 2% of it is fresh and less than 1% is easily accessible, with the rest locked up in the ice caps, atmosphere and soil. Already, over 2 billion people face high water stress, according to United Nations figures, and 4 billion experience severe water scarcity for at least one month every year. Those numbers will only increase as temperatures and the global population rise.

Separately, but connected of course, the oceans are the largest carbon sink on the planet. They absorb one quarter of all human-induced carbon dioxide emissions and capture 90% of the excess heat, calculates the Intergovernmental Panel on Climate Change. The growing number of weather-related natural disasters, which have been responsible for more than 2 million deaths over the past half century, are a stark reminder of the fact that global warming is already affecting us today.

The toll would be worse but for the critical role played by the oceans in absorbing CO₂ and heat. As a result, however, they are warming, acidifying, losing oxygen and sea levels are rising as arctic ice melts. This cascade of effects not only affects biodiversity, fishing and aquaculture, reducing food security; it will also limit their ability to absorb heat and CO₂ in the future.

Education and adaptation

Problems of this scale and complexity can be deeply intimidating. One of the biggest barriers to action -especially in developed countries- is that the threat often feels both abstract and remote. This perception makes it challenging to galvanize meaningful responses. Effective action requires global coordination and can appear prohibitively expensive or difficult to implement.

The key, therefore, is not only to educate people about how urgent and immediate our water-related challenges are, says Virgile Haddad, Sustainability Analyst at Bernstein, but also to shift our mindset from focusing solely on mitigation to including adaptation. “While mitigation tends to be based on technological solutions that are complex, long-term and costly, adaptation can be faster, more practical and easier to implement and can work at a local level,” he points out. 

In terms of raising popular awareness, a growing number of conferences in this area, such as June’s 2025 United Nations Oceans Conference in Nice and the Blue Economy and Finance Forum in Monaco are starting to serve a similar function to the annual COP meetings that seek solutions to climate change.  

The financial sector has an important role to play in connecting investors -who hold the capital and are increasingly eager to deploy it-, with the companies, governments and public-private partnerships focused on water-related solutions. While the recent track record of ESG funds has been mixed and the label itself has come under greater scrutiny Mr Ouaknine notes that more targeted strategies – such as water-themed ones – continue to attract meaningful inflows and demonstrate strong investor interest.

Corporations, meanwhile, will increasingly need to treat water as a strategic proxy for sustainability -much like carbon emissions have been over the past decade. That means developing specific water-related policies, measuring water use across their value chains, and responding proactively to growing regulatory and investor scrutiny. As pressures mount from climate change, population growth, and water scarcity, companies will be expected to demonstrate how they are managing one of the world’s most vital—and vulnerable—resources.

Simple and effective

The Bernstein team outlined numerous practical solutions to improve the sustainability of global water systems. By emphasizing adaptation over complex mitigation strategies, most of these measures can be deployed immediately using existing technologies and infrastructure.

One powerfully simple example is changing the way farmers irrigate crops. Agriculture accounts for 70% of our annual use of fresh water and 80% of that is used for irrigation. By switching from sprinklers or buckets to drip irrigation via long hoses with lots of small holes, four fifths of that water can potentially be saved. 

While drip irrigation can be ‘smartened up’ with the installation of sensors that collect data and monitor soil moisture, the basic application does not require sophisticated technology and is cheap to install. Moreover, it should make it easier for farmers, most of whom currently pay little or nothing for water, to eventually pay their share of a fair national or global water price. Establishing such a price would have a huge impact on overall consumption, of course, in the same what that a carbon price is damping CO₂ emissions.

Another way to conserve fresh water is to replace it with less-treated water (‘brown’ or ‘grey’ water) for applications in agriculture, industry and even urban, residential uses. Do our toilets need to be flushed with treated water, for example? Thermal power stations, which use enormous volumes of water for cooling - 40% of all fresh water withdrawals in the US and Europe - could switch to grey water in closed, circular systems rather than withdrawing it from rivers in ‘once-through’ cooling systems as most do now – though this would require upfront installation costs.  

Restoring or extending natural buffers like mangrove swamps, vegetation along riverbanks (riparian buffers) and flood plains can reduce the frequency of and damage from both floods and droughts, while also protecting biodiversity, preventing soil erosion and raising groundwater levels. Doing so, is effectively free. Meanwhile, improving the design of dikes and levees can often be done cost effectively, maintaining or restoring insurance cover to currently endangered residential areas. 

At the more technological end, desalination has the potential to convert the Earth’s effectively limitless supply of seawater into potable water. Although widely used in the Middle East, the process has failed to spread due to its cost and environmental footprint. However, new techniques are making desalination cheaper and powering it with renewable energy can eliminate additional CO₂ emissions. 

Morocco, for instance, is building Africa’s largest desalination plant, which will use reverse osmosis to produce 300 million cubic metres of water per year, enough to supply drinking water for 7.5 million people and support agriculture. The €613m project, which Societe Generale is helping to finance, will be powered by a nearby wind farm.

A different mindset

These examples demonstrate that there are many practical measures to adapt to and, in some cases, mitigate stresses on our global water systems while simultaneously fighting climate change and protecting biodiversity. 
Most are available already and often depend more on a change of mindset than significant economic and financial resources. While a global response will ultimately be needed, there is merit in starting small and locally. First, however, more of us must realize that having enough clean, fresh water to survive can no longer be taken for granted.