Climate Damage – Chasing Tales

In October 2023, Sikkim suffered a Glacial Lake Outburst Flood (GLOF)¹, which means that the Teesta River surged after the South Lhonak glacial lake burst, destroying the Chungthang dam, sweeping away 11 bridges, damaging NH-10² ³, and disrupting mobile coverage across northern Sikkim.⁴ Rescue operations were immediately hampered because road access, communications, and power failed at the same time. The government’s own situation reports noted that teams from multiple ministries had to be deployed simultaneously because all three systems had gone down together.⁵ Twenty-three Army personnel were among the missing.⁶ ⁷

In my previous post, I explored how climate change was affecting India’s national security with a broad brush, but while doing this I realised that civilian infrastructure is also, often, military infrastructure. And as everyone knows, India’s well known for the upkeep of her civilian infrastructure, and mild climate, so this post was born.

Systemic failure cascading through civil infrastructure is a danger to Indians and to India’s national security.

What Is Happening
Climate can damage infrastructure in two ways:

Disaster events, which are sudden unforeseen shocks, or the more mundane,
Daily stress due to newer ambient conditions, that among other impacts also compresses the window between maintenance cycles.

The former is usually visible, localised, and patched up through specially sanctioned money.

The Science

Chemistry
Most infrastructure is built from steel and concrete. Climate change affects both through several chemical processes.

Corrosion is the oxidation of steel, which is the process that produces rust. It is driven by a reaction that speeds up as temperature and humidity increase.⁸ Higher ambient temperatures and higher humidity therefore accelerate the corrosion of exposed steel and of steel reinforcement bars inside concrete.⁹ Studies have found that this reduces structural resistance and threatens the safety of buildings and infrastructure.¹⁰ ¹¹
For India’s coastal infrastructure, corrosion is intensified by chlorides from seawater and sea spray. Chloride ions penetrate concrete and break down the protective chemical layer on the steel reinforcement inside it.¹² Once that protective layer is lost, corrosion accelerates. As sea levels rise and storm surges push saltwater further inland, more structures are exposed to chloride-rich conditions than they were originally designed for.¹³ ¹⁴
Carbonation is another process affecting concrete.¹⁵ Carbon dioxide from the atmosphere reacts with calcium hydroxide in concrete, gradually lowering the concrete’s alkalinity. Concrete normally protects embedded steel because its high alkalinity creates a passive film on the rebar. When carbonation reduces that alkalinity, the steel loses that protection and becomes vulnerable to corrosion. Research suggests that under climate change, carbonation can advance much further than expected over a structure’s lifetime, potentially causing corrosion-related failure 15 to 20 years earlier than expected.

Physics
Climate change also affects infrastructure through physical processes.

Materials such as steel, concrete, and asphalt expand when heated and contract when cooled through a process called thermal expansion. Roads, bridges, and railway lines are designed with this in mind, using expansion joints and stress tolerances based on the historical temperature range of the area.¹⁶ When temperatures exceed those historical ranges more often, the materials expand more than expected. This can cause bridge cracking, road deformation, and rail distortion. India’s National Disaster Management Authority identifies all of these as current extreme heat risks.¹⁷
Thermal cycling fatigue is when repeated expansion and contraction over months and years creates cumulative mechanical stress.¹⁸ Tiny cracks form, widen, and eventually reduce the strength of the structure.¹⁹ This is especially important in regions with large temperature swings, including mountain areas where freeze-thaw and heat-cold cycles can be intense.²⁰
Freeze-thaw damage is a physical mechanism relevant to Himalayan infrastructure. Water enters small cracks in concrete or rock-supported structures.²¹ When it freezes, it expands and exerts pressure on the surrounding material.²² Repeated freeze-thaw cycles gradually widen cracks and weaken the structure. Roads, retaining walls, bridges, and tunnels in mountain zones are especially vulnerable to this.²³
Electrical infrastructure is also affected by basic physics. Transmission lines sag more in high heat because the metal expands.²⁴ ²⁵ Transformers and cables become less efficient as ambient temperature rises and can operate closer to their thermal limits for longer periods.²⁶ This reduces efficiency and can shorten equipment lifespan for equipment rated for a maximum ambient of 40°C, a threshold India’s plains now routinely exceed.²⁷
The troposphere, which is the lowest layer of the atmosphere, is getting wetter and more turbulent as climate change increases evaporation and convective activity.²⁸ ²⁹ Water vapour absorbs and scatters microwave signals. This creates what’s called tropospheric delay so that signals from GPS and navigation satellites arrive slightly later than they should because they’re passing through a more moisture-loaded atmosphere.³⁰ For civilian navigation this is a minor annoyance. For precision-guided systems, artillery corrections, or drone navigation that depend on GPS accuracy, accumulated error matters.³¹
Heavier rainfall also causes direct signal attenuation for satellites operating in the Ku and Ka frequency bands³², which are commonly used for broadband and military communications satellites³³. During intense monsoon rain events, which are becoming more intense, the signal can degrade significantly.³⁴ This is called rain fade.³⁵ Climate change is making extreme rainfall events more frequent, which means rain fade events are also more frequent.³⁶

Biology
Climate change changes biological conditions in ways that matter for infrastructure.

Mold and fungal growth increase when warm temperatures combine with moisture and poor ventilation. More humid conditions, heavier rainfall, and more water intrusion into buildings create better conditions for mold on and inside building materials. Mold does not usually collapse a bridge, but it does damage internal building materials, coatings, insulation, sealants, and indoor air quality, and it increases maintenance burdens in buildings.³⁷ The US Army Corps of Engineers identifies hot, humid conditions and climate-linked flooding as important drivers of mold risk in buildings.³⁸ ³⁹
Termites are another biological stressor. Research has found that termite decomposition activity increases sharply with temperature, with one study reporting an almost sevenfold increase for every 10°C increase in temperature.⁴⁰ Warmer conditions can lengthen termite active seasons and expand their range.⁴¹ In India, where termites are already a major issue in many regions, this can increase damage to wooden structures, fittings, and stored materials.⁴²
However, the most important biological effect may be on people, specifically the people who inspect, repair, and maintain infrastructure. Outdoor workers face direct heat stress. Studies from India show that high heat impairs hydration, reaction time, and cognitive performance, and reduces labour productivity.⁴³ One study found heat stress was associated with impaired cognitive function among outdoor workers in northeast India.⁴⁴ Another found significant productivity losses under high heat conditions in southern India.⁴⁵ Broader modelling suggests work performance in India could decline by 30-40% by the end of the century under high-emissions scenarios because of heat stress.⁴⁶ This matters because infrastructure maintenance is done by human beings. If workers can safely spend fewer hours outdoors, inspections are delayed, repairs take longer, and maintenance backlogs grow.

Why This Matters

Think of a bridge. It’s close to the Western front, but maybe somewhere hot rather than cold. Our troops and civilians use it. When war happens, it risks becoming a chokepoint. This is what climate change is doing to that bridge:

Chemistry

Atmospheric CO₂ rises → carbonation front advances through concrete → alkalinity drops → passive film on rebar breaks down
Simultaneously: Monsoon rainfall carries agricultural fertiliser runoff into the river→ sulfates and chlorides enter river water → they penetrate the concrete of bridge piers standing in the river → chloride ions attack rebar from below while carbonation attacks from above
All of this converges in the same steel. Corrosion begins. The steel expands as it rusts, cracking the concrete around it from the inside. The cracks then let in more water and more chlorides. The process accelerates itself.

Physics

Summer temperatures exceed original design range → expansion joints in the bridge deck are stressed beyond tolerance → micro-cracking at joints
Winter cold → contraction → same joints stressed in the other direction
This thermal cycling repeats every year → cumulative fatigue damage accumulates in the deck and in the connections between the superstructure and the piers
Monsoon floods → river scour around the bridge foundations → soil removed from around pier bases → foundations become more exposed, less supported
The cracks from thermal fatigue now provide entry points for the chloride-rich floodwater. The chemical and physical tracks have merged.

Biology

Heat + humidity + monsoon moisture → mold grows on bearing pads, sealants, and expansion joint filler → these materials degrade faster than designed
Summer wet-bulb temperatures rise → outdoor workers hit safe heat limits earlier in the day → inspection teams spend fewer hours on the bridge → the cracking goes unlogged for longer.
Maintenance is scheduled based on the old assumption of X inspections per year. The bridge now needs X+2. It might get X-1.

The military uses the national grid, national highways, ports, telecom networks, and fuel systems because these already exist at national scale.⁴⁷ Building separate military-only versions of all of them would be costly and, in many cases, impractical.⁴⁸

In forward areas, large fixed installations like wind turbines or solar arrays are visible on satellite imagery and can mark out military positions, a very obvious security liability.

There is also a wider internal security reason for treating civilian infrastructure as a national security issue: power failures, water shortages, and infrastructure breakdowns can contribute to unrest and instability. India has already seen public disorder linked to extended power cuts and water disruptions.⁴⁹ ⁵⁰

This means the military will continue to depend on civilian infrastructure in most cases. As a result, strengthening civilian infrastructure is not separate from strengthening national defence.

Each issue discussed in this post is treated in planning as a separate system with separate vulnerabilities. The problem is that they are not experienced separately.

They fail together.

India has a Ministry of Power, a Ministry of Jal Shakti, a Department of Telecommunications, a Ministry of Petroleum and Natural Gas, a Department of Space, and a Ministry of Road Transport and Highways. Each has its own climate resilience concerns, its own planning horizon, and its own budget. What India does not have is any institution whose job it is to look at all of these physical risks simultaneously and ask what their combined failure would cost during war, or during a 26/11-style attack.⁵¹ ⁵²

The cascade matters because the response to any single infrastructure failure can usually be managed: reroute the convoy, use the satellite phone, run the generator. It is when several failures occur in the same region simultaneously that the workarounds stop working. In a conflict scenario, an adversary that understands India’s infrastructure dependencies does not need to attack each system individually.⁵³ A weather event that the adversary did not cause, hitting infrastructure that climate change has already weakened, can achieve the same effect at no cost.⁵⁴ The Sikkim GLOF was not engineered. But the military vulnerability it exposed- an entire strategically sensitive zone simultaneously cut off by road, by communication, and by power- is exactly the condition a competent adversary would try to manufacture.

Sources

Tag: Climate Damage

Risk – VIII: A Hidden Vulnerability- Civilian Infrastructure in War

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