The strategic debate in South Asia is dominated by traditional security concerns, including the India-Pakistan rivalry, China’s growing presence in the region, rivalry in the Indian Ocean and the persistent threat of terrorism. But the region’s biggest long-term strategic problem is playing out beyond the conventional military realm. Climate change is slowly eroding the economic, institutional and resource basis on which national security ultimately depends. 

Governments are still investing heavily in military modernization and border management, but the rapid impacts of climate change are creating systemic vulnerabilities that deterrence as strategy cannot meet. This is not just an environmental issue. It’s a matter of economics and strategy. In fact, the Asian Development Bank estimates that South Asia could be losing close to 1.8% of its annual GDP by 2050 due to climate-related impacts, even with modest warming scenarios. 

At the same time, the World Meteorological Organization says Asia is warming almost twice as fast as the world average, accelerating glacier loss across the Hindu Kush-Himalayan region that supplies water to 11 major Asian river systems. These metrics matter because ultimately economic power feeds military capability, infrastructural development and state capacity. 

Climate shocks reduce agricultural productivity, disrupt industrial production, and strain state budgets and government disaster relief funds. Strategically, climate change is not supplanting geopolitical competition; it is altering the material conditions within which that struggle occurs.

Climate Change Altering Material Conditions

That is a growing reality, as recent experiences in the region show. In 2022, Pakistan experienced catastrophic flooding that submerged about a third of the country, affecting more than 33 million people, causing economic damages of over $30 billion, and slashing national GDP growth estimates by almost two percentage points. 

In India, prolonged heat waves have regularly exceeded 250 GW of energy consumption, exposing structural weaknesses in generation and transmission infrastructure and reducing labour productivity in the industrial and construction sectors. 

Bangladesh continues to lose thousands of hectares of coastal land to erosion and saline intrusion each year, resulting in internal displacement and putting pressure on already overcrowded metropolitan areas. 

Glacial lake outburst floods are also increasingly threatening the hydroelectric assets critical to the economic development of Nepal and Bhutan. 

Viewed in isolation these appear to be national environmental problems. But they do point to a regional strategic pattern: climate change is adding to budgetary strain, reducing resilience in infrastructure, intensifying competition over shared natural resources, and revealing institutional weaknesses that ignore national borders. The strategic importance of climate change is that it multiplies risks. 

Climate change, unlike traditional hazards, is rarely a source of instability in its own right. Instead, it compounds existing structural vulnerabilities such as poor governance, lack of resources, demographic pressures and uneven economic development. That has a knock-on effect across sectors that governments have traditionally seen as separate policy domains. 

Water insecurity affects agriculture and power generation; energy shortages constrain industrial expansion; falling livelihoods spur migration; and migration strains urban administration and public services. What begins as an environmental shock rapidly evolves into a multidimensional governance challenge with obvious national security consequences. The interlinkages are best illustrated by the transboundary river systems of South Asia.

Climate Change is Redrawing Geopolitics 

Climate change is reshaping South Asia’s strategic landscape in a sweeping manner, particularly regarding the control of shared waters. The Hindu Kush-Himalayan (HKH) region, known as the "Third Pole," contains the largest mass of ice outside the Arctic and Antarctic regions and is the source of the Indus, Ganges and Brahmaputra river systems that supply drinking water, agriculture, hydropower and industrial activity to around 1.9 billion people. In more extreme emission scenarios, glacier loss could exceed 50-65%, significantly affecting the seasonal flow of rivers. The consequences are far wider than environmental damage. South Asia’s water-sharing agreements were made on the presumption of a largely steady hydrological regime. 

The 1960 Indus Waters Treaty, often celebrated as one of the most resilient transboundary water treaties in the world, withstood multiple conflicts between India and Pakistan because river flows continued to be largely predictable. But climate-driven unpredictability creates uncertainty, which the treaty was not designed to address. More erratic monsoons, declining snowpack, extended droughts and sudden glacial melt increase the possibility of conflicts over water distribution, reservoir operations and infrastructure development.

The same sort of problems are now cropping up in the basins of the Ganges and Brahmaputra. India’s upstream position affords it considerable leverage over Bangladesh’s access to water downstream, but China’s expanding investments in hydropower plants along the upper Brahmaputra have become a source of strategic concern in New Delhi. Those trends are not necessarily leading toward war, but they are raising the political stakes in water control. With fresh water increasingly uncertain, governments will likely regard rivers as strategic assets tied to food security, energy generation and national resilience, rather than shared ecological systems. This represents a dramatic change in South Asian geopolitics. 

In the past, regional tensions have been focused on territorial disputes and military deterrence. Climate change is also raising the issue of resource security as an equally important dimension of interstate relations, requiring a greater focus on hydrological data sharing, joint watershed management and adaptive treaty processes. Existing agreements may be increasingly inadequate without institutional reform when climatic conditions depart from the norm of the past.

Energy Security Shifting to Climate Security

Climate change is also laying bare fundamental flaws in South Asia's energy grids at a time when electricity consumption is rising. The International Energy Agency (IEA) said India’s energy demand will grow faster than any other major economy in the next decade, driven by urbanization, industrialization, electrification of transport and rapid growth in digital infrastructure. In South Asia, higher temperatures and rising incomes are driving an unprecedented demand for air-conditioning, making cooling one of the fastest growing contributors to power use. Climate change, however, threatens the reliability of energy supplies. Thermal power plants and transmission systems are less efficient in very hot or very cold temperatures. 

In Nepal, Bhutan and northern India droughts reduce reservoir levels and limit the generation of hydro-electric power. Cyclones and floods damage transmission infrastructure leading to increased outages and maintenance costs. Therefore, there is a structural mismatch where peak electricity demand is increasingly coincident with declining system reliability.

India’s experience is one example of this growing vulnerability. Over the last few summers, power demand has gone over 250 GW, a record high, as long heatwaves have had extraordinary cooling requirements. Although the grid did not experience widespread failure, these events pointed to the growing reliance of economic production on climate-resilient infrastructure. 

Similar vulnerabilities are seen in Pakistan, where recurring energy shortages continue to hinder industrial productivity, and in Bangladesh, which is exposed to both climate and geopolitical shocks due to its reliance on imported fossil fuels. The strategic consequences will only intensify as South Asian economies become part of global digital supply chains. 

Artificial intelligence, semiconductor manufacturing, cloud computing and hyperscale data centres all require constant power and lots of water for cooling. Countries that do not develop climate-resilient energy infrastructure risk losing competitiveness in sectors expected to drive future economic growth. Climate resilience is no longer simply an environmental goal, but an industrial and technical requirement.

Climate Migration a Governance Challenge

One of the most politically significant impacts of climate change is more internal displacement. The World Bank’s Groundswell Report predicts that, without meaningful climate action, South Asia would have more than 40 million internal climate migrants by 2050. Rising sea levels, river erosion, salinisation, droughts and recurring flooding are already impacting human habitation patterns throughout the region. 

Bangladesh provides one of the most clear-cut examples. As cyclones become stronger and farmland becomes salty, people living near the coast are being forced to leave their homes. This is causing more people to move to cities such as Dhaka and Chattogram. 

Similar trends are occurring in India, where frequent droughts, floods and excessive heat have accelerated rural-urban migration. The floods that hit Pakistan in 2022 displaced millions of people. They are an example of how climate disasters can overburden government systems and trigger long-lasting humanitarian crises.

The migration itself is not the problem, but the burden on the government.” Rapid urbanisation increases demand for housing, healthcare, sanitation, jobs and public services in already overburdened cities. When governments shift resources toward reconstruction and social support, fiscal pressures mount, leaving little room to invest in long-term infrastructure or economic development. Climate migration is therefore a multiplier of existing developmental imbalances, adding to socioeconomic instability rather than being a standalone security hazard.

Institutional Bankruptcy in South Asia

While climate issues are transnational, regional cooperation remains fragmented. SAARC, long considered to be the main platform for South Asian cooperation, has been virtually paralyzed by continuing political conflicts, notably between India and Pakistan. Although initiatives like BIMSTEC and the BBIN framework have improved connectivity and energy cooperation, climate security hasn’t yet become a fundamental organizing principle in regional policy. 

The institutional divide is becoming more expensive. Rivers, electrical networks, migratory flows and supply chains cross national borders, but climate governance remains predominantly national in character. 

There is no regional framework in South Asia for assessing climate risk, coordinating disaster response, sharing hydrological intelligence and developing integrated adaptation strategies. Existing mechanisms are reactive not preventative. 

Climate change is reshaping national security in South Asia. Military preparedness, though important, cannot make up for decaying infrastructure, failing water systems, or recurrent economic disruptions brought on by extreme weather. Governments must expand the definition of security to incorporate climate resilience as a central strategic goal.

This means recontextualizing climate policy not merely as an environmental problem. It requires investments in climate-resilient infrastructure, modernized river governance, cross-border electrical integration, regional early warning systems and institutional frameworks that can respond to common ecological hazards. 

For many years, South Asia has been marked by geopolitical struggle. In the coming decades, the capacity to adapt to the evolving realities of climate security will increasingly shape not only its environmental fate, but also its economic security, political stability, and strategic equilibrium.

(The author is a climate researcher and columnist with experience in political research analysis, ESG research and energy policy. The views expressed are personal. She can be contacted at anusreetadutta.23@gmail.com )