The world’s road to water scarcity: shortage and stress in the 20th century and pathways towards sustainability

Abstract

Water scarcity is a rapidly growing concern around the globe, but little is known about how it has developed over time. This study provides a first assessment of continuous sub-national trajectories of blue water consumption, renewable freshwater availability, and water scarcity for the entire 20th century. Water scarcity is analysed using the fundamental concepts of shortage (impacts due to low availability per capita) and stress (impacts due to high consumption relative to availability) which indicate difficulties in satisfying the needs of a population and overuse of resources respectively. While water consumption increased fourfold within the study period, the population under water scarcity increased from 0.24 billion (14% of global population) in the 1900s to 3.8 billion (58%) in the 2000s. Nearly all sub-national trajectories show an increasing trend in water scarcity. The concept of scarcity trajectory archetypes and shapes is introduced to characterize the historical development of water scarcity and suggest measures for alleviating water scarcity and increasing sustainability. Linking the scarcity trajectories to other datasets may help further deepen understanding of how trajectories relate to historical and future drivers, and hence help tackle these evolving challenges.

Potential and Pitfalls of Frugal Innovation in the Water Sector: Insights from Tanzania to Global Value Chains

“…These drivers also increase the demand for domestic and industrial water, particularly in developing countries [20]. At the same time, one third of the global population (2.3 billion) live under high physical water scarcity (available water resources are insufficient to meet all demand) [21], while another 1.7 billion people live under moderate water scarcity [22]. Further, 1.6 billion live in areas under economic water scarcity (human, institutional, and financial capital limit access to water e.g., due to lack of infrastructure) [23].…”

Fuel Production from Seawater and Fuel Cells Using Seawater

“…[54] The acidified seawater is recombined with the solutions from the cathode and anode compartments and the overall reaction is given by Equation (16). [54] 2H 2 . The E-CEM configurationfor extraction of CO 2 and H 2 from seawater.R eprinted with permission from Ref.…”

“…Although fresh water is essential to maintain human life, the world is facing ag lobal and domestic challenge to reliably supply its population with fresh and safe water,o wing to shortagesr esulting from globalp opulation growth, [1][2][3] climate change, [4][5][6][7] contamination of clean water supplies, [8] and public policy. [9,10] Water is also needed to produce hydrogen as a clean and sustainable alternative energy source to fossil fuels by water splitting to prevent global warming stemmingf rom large-scale CO 2 emissions from the combustion of fossil fuels.…”

“…[9,10] Water is also needed to produce hydrogen as a clean and sustainable alternative energy source to fossil fuels by water splitting to prevent global warming stemmingf rom large-scale CO 2 emissions from the combustion of fossil fuels. [11][12][13][14][15][16][17][18][19][20] Therefore, water and clean energy are inextricably linked with each other.A bout 97 %o ft he water on our planet is seawater (3.0-5.0 %s alts) with 1.0 %b eing brackish ground water (0.05-3.0 %s alts), indicatingt hat the vast amounts of seawater would provide an early unlimited water supply if saline water could be used directly as ac lean and nearly infinite energy source.…”

“…(1)],b yh ydrolysis of Mg in seawater [Eq. (2)], [24] by decomposition of H 2 Si nB lack Sea deep water [Eq. (5)] [24][25][26] is demonstrated as ap roof of concept for the onsite production and use of renewable and sustainable energy.…”