Final answer:
Water scarcity arises primarily due to increasing population and demand, leading to excessive strain on limited water resources. Uneven distribution, climate change, and human activities further exacerbate the water crisis. Sustainable management is essential to address this growing global challenge.
Step-by-step explanation:
Water scarcity is a significant problem in the 21st century primarily due to C. Increasing population and demand. As the global populace continues to burgeon, the strain on existing water resources intensifies. Although water is a renewable resource through processes like evaporation and precipitation, uneven distribution and overuse in densely populated regions are leading to water shortages. These shortages are exacerbated by climate change and human activities such as excessive water use and water pollution. The water crisis is acute in areas with arid climates, rapidly growing populations, and insufficient infrastructure to treat and supply water. With projections indicating that by 2025 only half the world's population will have adequate access to clean water, it is clear that water scarcity presents a major challenge that needs to be addressed through sustainable management and technological innovations.