Mountains: the natural water towers under threat

To mark World Water Day, the UN is highlighting the crucial role played by glaciers and the need for more responsible management of our water resources. They are melting at an ever-accelerating rate, but sustainable solutions such as efficient water management, desalination and water treatment can offer a means of ensuring that future generations have access to a sufficient supply.

Some 4 billion people - in other words, half of the global population - currently suffer from severe water scarcity during certain periods of the year, and another 2 billion people do not have access to safely managed drinking water. These are some of the shocking figures shared in the UN World Water Development Report, released on World Water Day this year.

For 2025, the UN opted to spotlight ‘Glacier Preservation’ as the theme for the day: an incredibly pressing issue at a time when climate change is causing the ice caps to melt at an alarming rate, with severe consequences for the world’s water supply.

According to data from the World Meteorological Organization, approximately 70% of the fresh water on Earth exists in the form of snow or ice, with almost 2 billion people relying on the water that comes from glaciers, snowmelt and the subsequent runoff from mountains for drinking, agriculture and energy production. A truly essential source of water, yet it is suffering some rapid and dramatic changes: over the last year alone, glaciers lost more than 600 gigatonnes of water, making it the most significant loss of mass recorded in the last 50 years.

The water cycle and its challenges

The rate at which the glaciers are melting is making the water cycle more and more unpredictable. Meltwater flows are changing, triggering all manner of extreme events, periods of flooding and severe drought, as well as landslides and rising sea levels. It is of paramount importance that we reduce greenhouse gas emissions to slow the rate of shrinkage of our glaciers: limiting global warming to 1.5°C could save the glaciers in two thirds of World Heritage Sites. Above all, it is crucial to manage water in a more sustainable, organised way.

Water scarcity is becoming an increasingly serious problem: the World Resources Institute has shared that over 2.3 billion people are currently living in countries with high levels of water stress, and estimates show that by 2050, over half the global population could be affected by water scarcity issues.  Climate change is exacerbating this crisis, with periods of drought growing ever long and high temperatures reducing the amount of fresh water available.

The sustainable management of water resources

Promoting efficient water use through sustainable management policies is key to addressing the problem. The agricultural sector currently has the most significant demand for fresh water by far (72%), followed by the industrial sector (15%) and domestic or civil use (13%). The proportions of fresh water used by various sectors vary significantly from country to country, depending on their level of economic development.

Desalination and wastewater treatment: a responsible approach to water management

In order to tackle the worsening situation of water scarcity, there is a need to implement innovative solutions such as desalination and water treatment. Desalination makes it possible to obtain clean drinking water from seawater, with technological advances in the field making the practice an increasingly sustainable option. At the same time, wastewater treatment is a crucial means of reducing waste and securing our water supply. Treated water can be reused for irrigation, industrial purposes, and even for human consumption in some circumstances, reducing the strain on natural sources of water and thus protecting the environment.

Water reuse: an opportunity worth seizing

Both in Italy and at the wider European level, there is progress being made in this sector, though it is still a field with a great deal of untapped potential. In Italy, for example, up to 23% of the total volume of effluent has the potential for water reuse, corresponding to the proportion of wastewater that undergoes tertiary refinement treatment; however, a mere 4% of all purified wastewater is actually reused for agricultural purposes. At the European level, the situation appears to be broadly similar - albeit with some significant differences between individual countries - with an average reuse of just 2.4% of the total amount of wastewater produced, meaning that up to six times as much of this unconventional resource could potentially be salvaged.

Conclusions

Climate change is responsible for growing seasonal variations in water availability, resulting in unreliable supplies in many regions, whilst pollution, the degradation of our ecosystems and natural disasters can all compromise water resources even further.  Investing in modern infrastructure, reducing waste wherever possible and adopting responsible management policies are crucial steps to ensuring that future generations have access to water. The sustainable management of the water cycle, backed by technological innovations such as desalination and wastewater treatment, is the key to tackling the water challenges of the future.