Climate Change and Human Activities Threaten Oceans: Major Environmental Concerns Rise

Scientists have raised serious concerns over the deteriorating condition of the world's oceans due to climate change and excessive human exploitation. Two major issues have been highlighted in recent studies: the slowing down of the world's fastest ocean currents and the massive extraction of sand from the seas, both of which pose severe threats to marine life and the global climate system.

World’s Fastest Ocean Currents to Slow Down by 20% in Two Decades
A recent study by Australian scientists has predicted that some of the fastest ocean currents in the world could slow down by up to 20% in the next two decades. Researchers claim that melting Antarctic ice is weakening oceanic currents, which could have profound consequences on Earth’s climate system.
The study was conducted using one of the most powerful supercomputers in Australia, which showed that the melting of ice in Antarctica is reducing the strength of these powerful currents. The Antarctic ice sheet plays a crucial role in maintaining the speed and stability of ocean currents, but as ice melts, its impact on ocean circulation is becoming increasingly evident.
Professor Bishakhdatta Gayen, a lead researcher in the study, described the situation as extremely dangerous, emphasizing that the weakening of these strong ocean currents could disrupt global weather patterns and accelerate climate change.

800 Billion Tons of Sand Extracted Annually from Oceans: A Growing Ecological Threat
Meanwhile, another alarming environmental issue is the large-scale extraction of sand from the oceans. A recent study has revealed that nearly 800 billion tons of sand are being removed from marine environments every year, which is significantly impacting marine biodiversity and coastal ecosystems.
Between 1970 and 2019, the exploitation of natural resources, including sand mining, has more than tripled. The rapid extraction of sand is primarily driven by the booming construction industry, which relies heavily on sand and other raw materials. This excessive mining is causing severe damage to marine life, disrupting fragile underwater ecosystems, and contributing to coastal erosion.

Key Concerns of Sand Mining on Marine Ecosystems
1.    Threat to Marine Life: Despite efforts to conserve ocean ecosystems, large-scale sand extraction is leading to habitat destruction, affecting marine biodiversity.
2.    Increased Coastal Erosion: The removal of sand is weakening coastal protection, making shorelines more vulnerable to rising sea levels and extreme weather events.
3.    Impact on Climate and Water Scarcity: The overuse of sand and natural resources is accelerating climate change and contributing to water scarcity by disrupting natural water cycles.
The United Nations Environment Programme (UNEP) has also warned about the consequences of sand mining, stating that sand is the world’s second-most used resource after water. The rapid depletion of sand reserves is leading to a global environmental crisis.
Yamuna Pollution Worsens: Unchecked Sewage and Unauthorized Colonies Major Contributors
The Yamuna River, a lifeline for millions, continues to suffer from severe pollution due to unchecked sewage disposal and unauthorized settlements. Despite multiple efforts, including government initiatives, a parliamentary committee has emphasized the need for clear accountability among local municipal bodies for river conservation.

Key Reasons for Yamuna’s Deterioration
1.    80% Pollution from Domestic Sewage: The primary cause of pollution in Yamuna is untreated domestic wastewater, accounting for nearly 80% of the contamination.
2.    Numerous Drains but Poor Regulation: Of the 137 drains flowing into the Yamuna, only 35 are officially accounted for, while many remain unmonitored.
3.    Unregulated Urban Expansion: Unauthorized colonies in Delhi and neighboring states contribute heavily to sewage discharge, yet only 750 out of thousands of such colonies have proper sewage lines.
According to officials from Himachal Pradesh, urban sewage water does not directly enter the Yamuna there. However, four major drains from city boundaries do release wastewater into the river, worsening its pollution levels.

Alarming Pollution Statistics
•    22 km of the most polluted stretch: The section between Palla and Okhla, covering 22 kilometers, is the most critically polluted, receiving 75-80% of the total river pollution.
•    Only 2% Clean Water Flowing: In Delhi, just 2% of Yamuna contains clean water, while the rest is heavily contaminated.
•    Lack of enforcement: Pollution control boards acknowledge that many drains are unregulated, making effective monitoring nearly impossible.

Understanding River Health: 3 Critical Parameters
1.    Dissolved Oxygen (DO): Measures the ability of the river to support aquatic life.
o    0 mg/l:Dead river, cannot support life.
o    1-4 mg/l: Supports life at varying degrees.
o    6+ mg/l: Safe for drinking with treatment.
2.    Biochemical Oxygen Demand (BOD): Measures the river’s self-purification ability.
o    0-2 mg/l: Pristine condition.
o    3 mg/l: Suitable for bathing and drinking after treatment.
o    Above 3 mg/l: River is unfit for use.
3.    Faecal Coliform (FC): Indicates sewage contamination.
o    Up to 500 MPN/100 ml: Safe for bathing.
o    501-2,500 MPN/100 ml: Tolerable but risky.
o    Above 2,500 MPN/100 ml: Contaminated, unfit for use.

Five Urgent Measures to Revive Yamuna
1.    Restore Natural Flow: Yamuna currently receives only 16% of its flow in non-monsoon periods and 32% during monsoons. It needs at least 50-60% of its natural flow to begin healing.
2.    Establish Strong Leadership: A dedicated authority, like Namami Gange, should be set up to work on a strict three-year revival plan.
3.    Make Data Public: Sewage treatment plants (STPs) need real-time monitoring and public accountability, similar to air pollution data.
4.    Stop Sewage Flow & Effluents: The biggest pollution sources remain unaddressed as Haryana, Delhi, and UP fail to coordinate efforts, despite repeated court directives.
5.    Develop a Waterfront: Instead of political photo-ops, authorities should build a proper riverfront, fostering public ownership of the Yamuna's well-being.