Available water resources, even if renewable, are limited: while 71% of the world’s surface is covered by water, only between 0.3 and 0.5% available to drink. Of the total annual water withdrawal around the world, as much as 69% is destined to agriculture, 19% to industries and 12% to municipalities. United Nations Development Programme (UNDP), around 700 million people in 43 countries suffer today from lack of water and almost one-fifth of the world’s population live in areas of physical scarcity. The situation is only bound to worsen in the future due to the increase of population and climate change reducing water availability.
The change in the water cycle induced by global warming, with reduced rainfall and increased evaporation worldwide, and other interconnected impacts of climate change, such as ice melting and shrinking glaciers (which are an important reserve of water), heavy rainfall episodes and flooding (during which water rapidly moves into the oceans and it is difficult to retain for human usage), replacement of snow with rain, and so on, pose a growing threat to water security.
It is estimated that by 2025 almost half of the world’s population will be living in water-stressed areas and as many as 1.8 billion people in countries or regions with absolute water scarcity. The most impacted area in the world is Middle East and North Africa, where physical lack of water and projected impacts of climate change are interlaced with the highly unsustainable use of the available resources.