The Indus River system, a lifeline for millions in India and Pakistan, is under threat due to climate change. Recent studies by glaciologist Anil V. Kulkarni highlight how melting glaciers are affecting water availability, raising questions about the Indus Water Treaty (IWT), a 1960 agreement between India and Pakistan. This article explains Kulkarni’s findings, the need to rethink the IWT, and how glacier changes impact India’s water resources—all in simple terms.
What Did Anil V. Kulkarni Say?
Anil V. Kulkarni, a leading glaciologist at the Indian Institute of Science, Bengaluru, has warned that glaciers in the Indus River basin are melting unevenly. The glaciers feeding India’s eastern rivers—Ravi, Beas, and Sutlej—are shrinking faster than those supplying Pakistan’s western rivers—Indus, Jhelum, and Chenab. This difference is due to the altitude and location of the glaciers. Eastern glaciers, located at lower altitudes, are more vulnerable to warming temperatures, while western glaciers, in the higher Karakoram range, are more stable. Kulkarni predicts that by mid-century, water from eastern glaciers will decline significantly, reducing India’s water supply, while Pakistan’s rivers may see increased flows for a longer period.
Why Does the Indus Water Treaty Need a Review?
The IWT, signed in 1960, divides the Indus River system’s waters between India and Pakistan. India gets full rights to the eastern rivers (Ravi, Beas, Sutlej), while Pakistan controls the western rivers (Indus, Jhelum, Chenab). At the time, little was known about glaciers or climate change. Now, new data from satellite imaging and climate models show that glacier melt is changing water flows. Kulkarni argues that the treaty’s water-sharing rules, based on old assumptions, no longer match today’s reality. For example, India’s eastern rivers may soon have less water, while Pakistan’s western rivers could have more for some time. Reviewing the IWT with this new data is crucial to ensure fair water distribution and avoid conflicts.
Why Are Eastern Glaciers Retreating Faster?
Glaciers feeding the Ravi, Beas, and Sutlej rivers are at lower altitudes (closer to sea level) in the Himalayas, where temperatures are warmer. This makes them melt faster as global warming raises temperatures. In contrast, glaciers in Pakistan’s Karakoram range, which feed the Indus, Jhelum, and Chenab, are at higher altitudes where it’s colder. These glaciers are losing less ice and, in some cases, are stable or even growing slightly. Kulkarni’s studies show that by 2050, eastern river water from glaciers could drop sharply, while western river flows may increase temporarily before declining later.
What Is the Karakoram Anomaly?
The Karakoram anomaly is a scientific term describing the unusual behavior of glaciers in the Karakoram mountain range. Unlike most glaciers worldwide, which are shrinking due to climate change, Karakoram glaciers are either stable or slightly expanding. This is surprising because global warming typically melts glaciers. Scientists call it an “anomaly” because it defies the usual pattern. This stability means Pakistan’s western rivers have a more reliable water supply from glaciers compared to India’s eastern rivers.
What Causes the Karakoram Anomaly?
Scientists have identified several reasons for the Karakoram anomaly:
Cooler Summers: The Karakoram region experiences lower summer temperatures, reducing ice melt.
More Winter Snowfall: Heavy snowfall in winter adds more ice to glaciers, balancing out any melting.
Rock and Debris Cover: Many Karakoram glaciers are covered with rocks and debris, which act like a blanket, insulating the ice and slowing melting.
These factors make Karakoram glaciers more resilient to climate change than those in the eastern Himalayas.
How Will This Impact India?
The uneven melting of glaciers creates a big challenge for India. The eastern rivers (Ravi, Beas, Sutlej), which India relies on for irrigation, drinking water, and hydropower, will see reduced water flows after 2050. This could lead to water shortages, affecting farmers, cities, and industries in northern India, especially in states like Punjab and Himachal Pradesh. Meanwhile, Pakistan’s western rivers, with more glacier-stored water, will likely have more water until later in the century. This imbalance could strain India-Pakistan relations, as India may feel shortchanged by the IWT’s current terms. Kulkarni warns that without action, India’s water security could be at risk.
What Studies Have Been Done?
Kulkarni and his team have used advanced tools to study the Indus basin:
Satellite Data: Since the early 2000s, satellites have provided detailed images of glacier size and retreat.
Climate Models: These predict how glaciers will change based on temperature and precipitation trends. For example, models show eastern river flows peaking by 2030 and dropping sharply by 2100.
Field Studies: Kulkarni’s team has visited glaciers, like those in Spiti Valley, to measure ice loss directly.
A 2023 study in Current Science by researchers from the Indian Institute of Science and others found that all Indus sub-basins, except the Upper Indus, are losing glacier mass rapidly. Another report by the International Centre for Integrated Mountain Development (ICIMOD) confirmed that Himalayan glaciers are melting faster than Karakoram ones, affecting water availability.
How Can India Use Eastern Rivers Differently?
With the IWT currently under review (put on hold in April 2025 due to tensions with Pakistan), India has more flexibility to manage its eastern rivers. One key strategy is reservoir flushing, which involves releasing water from dams to clear out sediment (mud and silt) that builds up. This sediment can reduce a dam’s storage capacity and increase flood risks. Under the IWT, flushing was restricted, and refilling reservoirs had to happen during the monsoon season (August), which wasn’t always ideal. Now, India could:
Flush reservoirs at better times, like before Pakistan’s sowing season, to maximize benefits.
Build new dams or modify existing ones (like Bhakra on the Sutlej) to store more water during high-flow years.
Use flushed water for irrigation or hydropower, improving water management in dry seasons.
These steps could help India make the most of its shrinking glacier water while addressing flood risks and sediment buildup.
Why Is This Topic Important for UPSC and State PCS Exams?
The issue of glacier retreat and the Indus Water Treaty is highly relevant for UPSC and State PCS exams because:
Geography: Questions often cover climate change, river systems, and their impact on India’s environment and economy. Understanding glacier dynamics and the Indus basin is key.
International Relations: The IWT and India-Pakistan water disputes are critical for bilateral relations, a frequent exam topic.
Environment and Ecology: Climate change’s effect on water resources is a major concern in India, tested in both prelims and mains.
Current Affairs: Recent developments, like India’s 2025 decision to pause the IWT, make this a hot topic for essays and interviews.
Policy and Governance: Water management and treaty revisions involve complex policy decisions, relevant for public administration questions.
For example, UPSC mains might ask, “Discuss the impact of climate change on the Indus Water Treaty and its implications for India’s water security.” Knowing Kulkarni’s findings and the Karakoram anomaly helps craft a well-rounded answer.
Anil V. Kulkarni’s research shows that climate change is reshaping the Indus River system, with India’s eastern glaciers melting faster than Pakistan’s western ones. This threatens India’s water supply and calls for a review of the 1960 Indus Water Treaty using new data. The Karakoram anomaly highlights why Pakistan’s rivers are more stable, but India can adapt by better managing its eastern rivers, like through reservoir flushing. Understanding these changes is vital for India’s water security and for aspirants preparing for competitive exams like UPSC and State PCS.
