Disaster Management, Science & Technology, Technology, UPSC
Q.15. The world is facing an acute shortage of clean and safe freshwater. What are the alternative technologies which can solve this crisis? Briefly discuss any three such technologies citing their key merits and demerits. [UPSC 2024 GS P-3]
The global shortage of clean and safe freshwater is a well-documented crisis. Here are key data points that highlight the severity of this issue:
- Global Water Scarcity:
- 2.3 billion people live in water-stressed countries, with 733 million experiencing high and critical levels of water stress, according to the UN (2023).
- By 2025, 1.8 billion people are expected to be living in countries or regions with absolute water scarcity, and two-thirds of the global population may be under water-stressed conditions (UN-Water).
- Lack of Access to Clean Water:
- 771 million people (approximately 1 in 10 globally) lack access to basic drinking water services, as reported by the WHO and UNICEF (2022).
- 144 million people rely on surface water, such as lakes and rivers, for their daily needs, which is often unsafe and contaminated.
- Agriculture and Water Demand:
- Agriculture accounts for approximately 70% of global freshwater withdrawals, and with rising food demand, water use for farming is expected to increase by 50% by 2050 (FAO).
- By 2050, it is projected that global water demand will increase by 55% due to growing needs from agriculture, industry, and domestic use (OECD).
- Impact of Climate Change:
- Climate change is exacerbating water shortages, with 1.6 billion people expected to face absolute water scarcity by 2040 due to changing precipitation patterns, more frequent droughts, and extreme weather events (World Bank).
- 700 million people could be displaced by intense water scarcity by 2030 (UNDP).
- Water Pollution:
- Over 80% of wastewater worldwide is discharged into the environment without any treatment, leading to contamination of freshwater sources (UNESCO).
These figures illustrate the growing imbalance between freshwater availability and demand, highlighting the urgent need for sustainable water management and alternative technologies. Here are three promising technologies that can help alleviate the freshwater shortage:
1. Desalination
Merits:
- Converts seawater into freshwater, providing a virtually unlimited source of drinking water.
- Useful in arid regions and areas facing chronic water shortages.
- Can supply water to coastal cities where freshwater sources are limited.
Demerits:
- High energy consumption, making it expensive and environmentally taxing.
- Disposal of highly concentrated brine can negatively impact marine ecosystems.
- Desalination plants require significant infrastructure investments.
2. Rainwater Harvesting
Merits:
- Simple and cost-effective technology for capturing and storing rainwater.
- Can be implemented on both small (household) and large (community) scales.
- Reduces demand on municipal water supply and helps replenish groundwater levels.
Demerits:
- Seasonal dependency; effectiveness is limited in regions with low or irregular rainfall.
- Requires regular maintenance to prevent contamination and ensure water quality.
- Storage limitations may arise in areas with inadequate space or infrastructure.
3. Greywater Recycling
Merits:
- Reuses lightly used water from sinks, showers, and washing machines for purposes such as irrigation and toilet flushing.
- Reduces overall water consumption and wastewater production.
- Can significantly cut down the demand for potable water in households and industries.
Demerits:
- Installation costs can be high for retrofitting existing buildings.
- Requires treatment to prevent health risks from bacterial contamination.
- Public acceptance may be low due to hygiene concerns associated with reused water.
These technologies, while effective, have challenges related to cost, environmental impact, and societal acceptance. However, with further advancements, they offer potential solutions to the global freshwater crisis.
