Belgian North Sea faces seven priority climate risks as Ostend sea level rises 23.6 cm

The report

On Monday, 9 November 2026, the Institut des sciences naturelles and the Cerac (Centre d'analyse des risques liés au changement climatique) published a joint report on the Belgian part of the North Sea. The area covers 3,456 square kilometres, and the report says it has already changed over recent years. The authors argue that climate risks seldom occur in isolation, so they assess them together. They identify seven priority climate risks for these waters. The climate pressures sit on top of existing activity there, including shipping, fishing, offshore energy and sand extraction.

Sea level and sea temperature

Sea level at Ostend rose 23.6 cm between 1951 and 2024, which equals about 3.2 mm a year on average. That rate has accelerated, and since 2015 it has exceeded 5 mm a year. Sea surface temperatures have also risen over several decades. Summer 2026 produced the largest marine heatwave recorded so far in Belgian waters. Reporting on that summer puts the heatwave at 87 days, the longest ever recorded. Such heatwaves disrupt marine ecosystems.

Seven risks for ecosystems and infrastructure

The report names displacement of species, degradation of ecosystems, harmful algal blooms and damage to maritime and coastal infrastructure among its seven priority risks. Some fish species are already changing where they live, while species suited to warmer water are being observed more frequently. Ports, offshore wind farms, submarine cables and coastal protection structures could face greater exposure as rising sea levels combine with extreme events. In a 2°C warming scenario, the report rates the risk of damage to these infrastructure assets as 'critical'. The effects of climate change therefore add to pressures that already exist across the 3,456 square kilometres.

Recommendations and scope

The researchers recommend integrating climate change more fully into existing maritime policies. They also call for stronger preparation for emergency situations. According to the report, the likelihood and severity of the risks, along with the cost of adaptation, rise with each additional degree of global warming. The assessment covers only the Belgian part of the North Sea, so its findings describe those waters rather than the wider sea. The authors expect the trends already visible to intensify as warming continues.