Global Water Scarcity Due to Climate Change and Its Conservation Strategies With Special Reference to India : A Review

Abstract

The strategic importance of fresh water for global water and food security will probably intensify under climate change which worsen the situation as it leads to increased frequency and intensity of climatic extremes such as flood, drought, cyclone, heat/ cold waves, alteration in water cycle, water resources depletion, increased variability of precipitation, salt water intrusion in aquifers, increasing irrigation demand, decreasing soil moisture and rapid evaporation of surface water and many more. This review provides an insight about climate change and its impact on quantity and quality of water, water scarcity on a global scale with emphasis on Indian water resources, its availability and conservation strategies to mitigate water scarcity. Global warming resulting in climate change is expected to account for about 20% of the global increase in water scarcity. Global water consumption has increased six fold in last century and in coming decades is expected to grow rapidly. By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world's population could be living under water stressed conditions. African continent is the worst affected by the scarcity of water. The gross per capita water availability in India will decline from about 1820 m3 per year in 2001 to as low as about 1140 m3 per year in 2050. It is estimated that the country would need 1180 billion cubic meters (BCM) of water annually by 2050. So, there is an urgent need of sustainable utilization of water resources, formulation of climate adaption strategies, making the people and government aware about shrinking water resources as well as taking urgent action for conservation and harvesting of water at local, national and global scale.

Microalgae-Mediated Biosorption for Effective Heavy Metals Removal from Wastewater: A Review

“…The continuous growth of the global urban population, anticipated to grow by 2.7 billion between 2015 and 2050, is expected to reach over 9 billion in 2050, intensifying the strain on water resources [2]. By 2025, an estimated 1.8 billion individuals may inhabit nations facing absolute water scarcity, with two-thirds of the global population confronting water-stressed conditions [3]. Projections indicate that the global urban population experiencing water scarcity is poised to increase to 1.7-2.4 billion by 2050 [2].…”

“…These substances, originating from natural processes and human activities, are commonly released into the environment [10]. They often possess atomic weights higher than iron and densities below 5 g/cm 3 , finding applications in various industries, including smelting, finishing, coal, electroplating, photography, aerospace, waste management, transportation, mining, and agriculture [11,12]. Essential metals like copper (Cu), nickel (Ni), chromium (Cr), mercury (Hg), cadmium (Cd), zinc (Zn), and lead (Pb) are prevalent in industrial processes, emphasizing their role in determining water quality [13,14].…”