As oceans warm and weather patterns grow more unpredictable, cargo losses linked to heat and moisture are increasing. Understanding how climate conditions affect cargo is becoming essential to managing risk and preventing claims.

Cargo claims linked to heat, moisture and severe weather are becoming increasingly common across global trade routes. Losses that were once regarded as exceptional are now appearing with greater frequency, affecting a wide range of commodities and geographies. From a claims perspective, the pattern is clear. Containers are getting hotter, humidity levels are rising, and voyages are more often exposed to volatile weather conditions. Climate change is no longer a background issue for shipping, but a direct operational risk.

The commercial impact is already being felt. Cargo arrives discoloured, deformed or degraded, despite having been packed and stowed in accordance with accepted standards. Delays caused by storms or port closures increase exposure time, compounding the risk of damage. For cargo owners, ship operators and insurers, this evolving risk landscape is reshaping both expectations and outcomes.

From rising temperatures to rising claims

Global temperatures have increased by approximately 1.1 degrees Celsius since 1880, with the last decade confirmed as the hottest on record. Oceans have absorbed nearly 90 percent of this excess heat, altering sea surface temperatures, wind patterns and atmospheric moisture levels along major shipping routes.

These changes have practical consequences for cargo in transit. Steel container surfaces can exceed 55 degrees Celsius during periods of intense solar radiation, even when ambient air temperatures are significantly lower. Inside containers, these extreme microclimates accelerate oxidation, polymer softening and biochemical spoilage. Heatwaves at sea, often lasting longer than in the past, increase the duration of exposure and the likelihood of irreversible damage.

Humidity presents an equally significant challenge. Warmer air holds more moisture, around 7 percent more for every degree Celsius of warming. When temperatures drop during night hours or extended crossings, this moisture condenses inside containers. Cargo sweat forms on goods, while ship sweat develops on container walls and ceilings before dripping onto cargo below. The resulting damage often includes mould growth, corrosion, weakened packaging and contamination.

Different cargoes respond in different ways. Perishable goods such as meat, seafood and pharmaceuticals degrade rapidly when temperature thresholds are exceeded. Electronics may overheat and malfunction. Canned and bottled products can rust, leak or crack. Chemicals may degrade or become unstable, while volatile substances can transfer heat to adjacent cargo. Organic and hygroscopic commodities such as coffee, corn and timber add further complexity by releasing moisture when exposed to heat, increasing the risk of secondary condensation damage.

What claims investigations are revealing

Recent investigations by Charles Taylor Adjusting illustrate how these environmental factors translate into real losses.

In one case, photographic paper rolls were shipped from Jakarta to Makassar in a standard dry container. On arrival, the cargo was discoloured and chemically compromised, despite intact packaging. Laboratory analysis confirmed that sustained exposure to temperatures between 30 and 50 degrees Celsius was sufficient to damage the product. Internal container temperatures reached this range due to solar radiation, even though external temperatures were recorded at approximately 31 degrees. The resulting loss was estimated at US$60,000. The investigation concluded that refrigerated transport set to 10 degrees would have been appropriate for this cargo.

In another case, polyamide roof rail assemblies were transported from Thailand to Jakarta. The cargo was well packed and secured, yet on arrival, the components had expanded beyond acceptable tolerances. Polyamide is hygroscopic, meaning it absorbs moisture from the surrounding air. Prolonged exposure to high humidity, heat and temperature fluctuations during transit led to dimensional swelling. As a result, 390 sets were rejected and returned, with urgent air freight replacements required to maintain production schedules.

These cases demonstrate that climate related damage can occur even where handling and packing meet accepted standards. The environment itself has become a critical factor in cargo performance.

Adapting to a more volatile operating environment

Climate volatility is affecting not only individual shipments, but the wider shipping system. Severe weather is responsible for a growing number of port disruptions and operational stoppages. Research by Marcura Intelligence indicates that ports in Asia and Africa are particularly vulnerable to wind related delays, sometimes halting operations for weeks. These disruptions extend voyage times, increase congestion and raise the likelihood of cargo deterioration while vessels wait at anchor.

In response, the shipping industry is adapting. Operators are increasingly using advanced weather routing and real time forecasting tools to avoid high risk areas and improve voyage planning. Ports are investing in stronger infrastructure, improved drainage and cold chain upgrades to better withstand flooding and heat. In some regions, nature-based solutions such as mangrove restoration are being used to protect coastal and port assets.

Lian Charlos

Shipowners are also investing in more resilient vessels, with stronger hulls, improved lashing systems and energy efficient engines designed to operate safely in harsher conditions while reducing emissions. At a regulatory level, the International Maritime Organization (IMO) continues to drive the transition towards lower carbon shipping through efficiency standards, carbon pricing mechanisms and long term emissions reduction targets.

For insurers and cargo interests, prevention is becoming increasingly important. Marine cargo policies offer varying levels of protection against weather related risks, but exclusions remain for improper packing, inherent vice and delay without physical damage. Practical risk mitigation measures, such as pre shipment cargo conditioning, the use of insulated or refrigerated containers, moisture control through desiccants, and careful route monitoring, can significantly reduce exposure.

Climate change is now part of everyday logistics. While the challenges it presents are substantial, many of the associated risks can be managed through preparation, collaboration and a clear understanding of how cargo behaves under changing environmental conditions. In an increasingly unpredictable climate, prevention remains the most effective form of protection.
Source: By Lian Charlos Tri Firts Mory, Assistant Director, Charles Taylor