Warming Oceans Hit Record Heat: WMO Warns Coastal Communities Face Rising Risks

The warning of the 2026 El Niño demonstrates how sustained ocean observations can help countries prepare for climate-related emergencies before their impacts become severe.

The world's oceans are absorbing increasing amounts of heat, creating serious challenges for marine ecosystems, coastal communities and countries already struggling with the effects of climate change. According to the World Meteorological Organization (WMO), global ocean heat content reached a record high in 2025 for the ninth consecutive year, reflecting the continued accumulation of heat beneath the ocean's surface. Rising ocean temperatures are contributing to stronger tropical storms, changing rainfall patterns and more intense marine heatwaves, threatening fisheries, food supplies and livelihoods across different regions.

In her opening message for the WMO Bulletin, Volume 75, Issue 2: The Warming Ocean, WMO Secretary-General Celeste Saulo emphasized the importance of international cooperation in monitoring ocean conditions and preparing communities for future climate risks. She explained that reliable observations provide essential information for understanding changes in ocean temperatures, predicting extreme weather and helping governments make decisions that protect people and infrastructure. The publication brings together scientific findings and practical experiences from different countries, showing how ocean monitoring contributes to weather forecasting, climate prediction and early warning systems.

The warning of the 2026 El Niño demonstrates how sustained ocean observations can help countries prepare for climate-related emergencies before their impacts become severe. As the event strengthens, seasonal forecasts are helping governments anticipate possible droughts, flooding and extreme heat in different parts of the world. Combining these predictions with national weather services and local early warning systems can give vulnerable communities more time to protect their homes, livelihoods and essential resources.

Record Ocean Heat Threatens Marine Life and Coastal Communities

Increasing ocean temperatures are changing marine environments and creating conditions that can intensify extreme weather events across the planet. Warmer ocean waters provide additional energy for tropical storms and influence atmospheric circulation, affecting rainfall and weather conditions in regions far beyond coastlines. These changes can increase the challenges faced by communities dependent on agriculture, fishing and climate-sensitive economic activities.

Marine heatwaves are becoming more frequent and intense, exposing marine species and habitats to prolonged periods of unusually warm water. Such events can damage marine ecosystems, disrupt fisheries and reduce income opportunities for coastal populations whose livelihoods depend on healthy ocean environments. Rising sea levels add further pressure by threatening coastal infrastructure, increasing flooding risks and placing food security and local economies under greater strain.

The WMO Bulletin examines how ocean warming and the ocean's absorption of carbon dioxide influence the global climate system and marine environments. Scientific contributions explore the impacts of marine heatwaves, the importance of ocean observations for improving hurricane forecasts in the Caribbean and the ways Pacific communities are responding to rising sea levels. These findings demonstrate why understanding the ocean is essential for managing climate risks and developing practical responses suited to regional conditions.

Better Ocean Monitoring Can Improve Extreme Weather Warnings

Accurate weather and climate forecasts depend on continuous observations of ocean temperatures, currents and other environmental conditions collected through monitoring systems around the world. WMO has emphasized the need to expand these observations, particularly in deep ocean waters, coastal areas and poorly monitored regions such as the Southern Ocean. Limited information from these locations can make it harder for scientists to understand important changes and improve predictions of developing climate hazards.

New technologies and partnerships are creating opportunities to collect ocean information from areas that traditional monitoring networks cannot easily reach. Fishing vessels and commercial ships can contribute valuable measurements during their regular operations, supporting wider observation coverage without relying entirely on dedicated research expeditions. Autonomous monitoring technologies can also gather information from remote ocean environments, strengthening the scientific understanding of warming trends and changing marine conditions.

Reliable observations become especially valuable when information reaches forecasting centres quickly enough to support timely predictions and warnings. National meteorological services can use these findings to improve hurricane forecasts, seasonal climate outlooks and marine information services for coastal communities and maritime industries. Better communication between scientists, forecasting agencies and local authorities can help ensure that warnings translate into practical measures before dangerous conditions develop.

WMO Calls for Stronger Investment and Global Cooperation

The WMO Bulletin highlights the importance of sustained investment in ocean observation infrastructure, scientific expertise and international partnerships to understand the changing marine environment. Maintaining existing monitoring networks and extending coverage into underserved regions will require continued cooperation between governments, researchers, national meteorological agencies and organizations working across the maritime sector. Stronger technical capabilities can help countries improve climate predictions and develop services that respond to the needs of coastal populations and industries.

International collaboration also plays an important role in ensuring that ocean observations are shared and converted into information that communities can use. Countries need reliable forecasting systems, trained specialists and effective communication networks to transform scientific measurements into early warnings about storms, flooding and other climate-related threats. Supporting these capabilities is particularly important for vulnerable regions where limited resources can restrict access to advanced monitoring technologies and timely climate information.

Celeste Saulo's message emphasizes that the ocean will continue changing, making decisions about observation systems and climate preparedness increasingly important for the years ahead. Protecting communities from the impacts of ocean warming will depend on maintaining reliable monitoring networks, improving international data sharing and ensuring scientific findings reach people facing the greatest risks. Continued investment in ocean science and early warning services can help countries prepare more effectively for changing climate conditions and reduce the dangers facing coastal communities, marine ecosystems and livelihoods worldwide.