How can pollution weather changes and population growth increase water scarcity?

Water scarcity occurs when the demand for freshwater exceeds the available supply. Pollution, weather changes, and population growth exacerbate this crisis in the following ways:12

• Pollution: The introduction of heavy metals, toxic chemicals, municipal sewage, and agrochemical runoff degrades water quality, rendering existing supplies unsafe or unusable. Because over 80 percent of global wastewater is released into the environment without treatment, these pollutants contaminate vital freshwater sources, effectively reducing the amount of clean water available for human and environmental needs.134
• Weather Changes: Global warming is shifting climate patterns, leading to more frequent and intense extreme weather events. These changes disrupt natural water cycles, often resulting in prolonged droughts or unpredictable rainfall that limit the replenishment of surface water and groundwater reserves.15
• Population Growth: As the global population increases, the demand for water for municipal, agricultural, and industrial use rises significantly. This surge in consumption often outpaces the natural recharge rate of water sources, placing immense pressure on existing water supply systems and infrastructure.165