Indian Ocean Warming Accelerates: Rising Temperatures and Climate Impacts

The Indian Ocean has been warming rapidly, with temperatures rising by 0.15°C per decade between 1951 and 2015. The Northern Arabian Sea has experienced an even faster increase, with temperatures rising 1.5°C in the last decade, while some parts of the southern Arabian Sea recorded a 0.75°C rise. A key driver of this warming is the decaying phase of El Niño, which contributes to 70%–80% of heatwave days in the Indian Ocean. Additionally, cyclones and salinity intrusion are severely affecting coastal areas, damaging freshwater sources, reducing agricultural productivity, and harming ecosystems like wetlands and mangroves.

The frequency and duration of marine heatwaves (MHWs) have also surged, increasing by about 20 days per decade, particularly in the Arabian Sea. Looking ahead, the Indian Ocean is expected to warm by 1.7°C–3.8°C per century, leading to stronger monsoons, cyclones, and a major decline in marine productivity. Climate scientist Roxy Mathew Koll compared this heat increase to the energy of one Hiroshima bomb explosion per second for a decade.

Meanwhile, a Climate Central study found that India ranked fifth in Asia for abnormal heat between December 2024 and February 2025, with over 358 million people affected. Maharashtra and Mizoram recorded the highest temperature anomalies, 1.6°C above normal. Climate change is already posing severe health risks, with 394 million people worldwide experiencing extreme heat exposure, especially in Africa, the worst-affected region.

Indian Ocean Warming Accelerates: Rising Temperatures and Climate Impacts

The Indian Ocean is warming at an unprecedented rate, with temperatures rising by approximately 0.15°C per decade from 1951 to 2015, according to India’s Ministry of Earth Sciences (MoES). During a recent Lok Sabha session, Minister Jitendra Singh presented alarming data from advanced sea surface temperature records, emphasizing that the northern Arabian Sea is experiencing even faster warming. This trend poses serious risks to weather patterns, marine ecosystems, and coastal communities.

Accelerated Warming in Key Regions

Over the past decade, the northern Arabian Sea has witnessed a temperature increase of 1.5°C annually, while parts of the southern Arabian Sea have warmed by 0.75°C. When questioned by BJP MP Parshottam Rupala about worsening climate impacts, Singh attributed the extreme heat in the Indian Ocean to the fading phase of El Niño—a natural climate phenomenon responsible for 70–80% of marine heatwaves in the region. These heatwaves disrupt ocean ecosystems and contribute to stronger cyclones, unpredictable monsoons, and saltwater intrusion into freshwater sources.

Ripple Effects on Coastal Communities

Rising ocean temperatures pose significant threats not only to marine life but also to human populations. Frequent cyclones trigger storm surges, pushing saltwater inland. This salinity intrusion contaminates drinking water, reduces agricultural productivity, and damages fragile ecosystems such as wetlands and mangroves. These changes endanger livelihoods, particularly in fishing and farming communities that depend on coastal resources.

Marine Heatwaves: A Growing Crisis

The minister highlighted the rapid increase in marine heatwaves, particularly in the northern and southeastern Arabian Sea. Over the past few decades, these heatwaves have extended by approximately 20 additional days per decade, severely impacting marine habitats and intensifying extreme weather. Warmer ocean temperatures provide more energy for cyclones, leading to stronger storms and unpredictable rainfall patterns during the monsoon season.

A Hotter Future Ahead

Studies predict that the Indian Ocean—already the fastest-warming ocean basin—will heat up by 1.7°C to 3.8°C per century from 2020 to 2100 if current trends persist. This could result in more severe weather events, prolonged marine heatwaves, and a drastic decline in fish populations. Climate scientist Roxy Mathew Koll compared the projected heat increase to the energy equivalent of detonating one Hiroshima atomic bomb every second for ten years. Such warming could lead to the collapse of marine food chains, impacting millions of people who rely on the ocean for sustenance and income.

Unusual Winter Heat in India

A separate study by U.S.-based Climate Central found that India experienced exceptionally high winter temperatures between December 2024 and February 2025. Ranking fifth in Asia for temperature anomalies, 12 Indian states—home to over 358 million people—faced extreme heat. Maharashtra and Mizoram recorded winter temperatures 1.6°C above normal, the highest in the country. Climate scientist Kristina Dahl stressed that climate change is no longer a distant threat but a present-day crisis, with heatwaves becoming increasingly frequent and intense due to continued fossil fuel emissions.

Global Heatwaves Intensify

Worldwide, over 394 million people endured extreme heat during the same period, with African nations being the most severely affected. In 287 cities globally, residents experienced at least a month of climate change-induced heat. These trends highlight the urgent need for action to reduce emissions and adapt to rising temperatures.

The Time to Act is Now

The rapid warming of the Indian Ocean and its cascading effects—from more powerful cyclones to declining fish populations—underscore the immediate threat of climate change. Without substantial reductions in greenhouse gas emissions, extreme heat, unpredictable monsoons, and coastal disasters will continue to intensify, affecting food security, economies, and public health. As Minister Singh and climate experts warn, this crisis is no longer a distant possibility but a present reality that requires urgent global cooperation and sustainable solutions.