The North Sea is rising, and Belgium’s coastal defenses may not be keeping pace. With sea levels accelerating and storms threatening increasingly costly damage, scientists warn that urgent action is needed to protect coastal towns, ports, and critical infrastructure.

A new report by the Royal Belgian Institute of Natural Sciences (RBINS) and the Center for Risk Analysis of Climate Change (Cerac), released at the start of the UN climate summit in Antalya, warns that Belgium is running out of time to prepare.

In Ostend alone, sea levels have risen by more than 23 centimeters since 1951. Without additional protective measures, coastal flooding could cause up to €200 million in annual damage to buildings and infrastructure under a 2°C global warming scenario. Yet significant gaps remain in Belgium’s coastal defenses, particularly around the ports of Zeebrugge, Ostend, and Nieuwpoort.

The Flemish Department of Environment, which includes the Agency for Maritime Services and Coast, even assumes an annual sea-level rise of 3.5 millimeters.  If the Earth warms by 2°C and no adaptation measures are taken, flooding could cause approximately 200 million euros in annual damage to buildings and infrastructure along the Belgian coast.

The Netherlands

Projections for the year 2100 from the Dutch meteorological institute KNMI indicate a sea-level rise along the Dutch coast of 26 to 73 centimeters under a low-emissions scenario and 59 to 124 centimeters under a high-emissions scenario.

If the massive Antarctic ice sheets begin to melt at an accelerated rate, this rise could reach up to 2.5 meters – a prospect that becomes increasingly plausible if global warming exceeds 2°C.

Global sea levels are rising due to three factors: the expansion of warming seawater, the melting of mountain glaciers, and the melting of the ice sheets in Greenland and Antarctica. Moreover, this rise is accelerating; since 2015, the rate has climbed to between 5 and 10 millimeters per year.

‘New coastal vision’

Belgium’s coastal defenses are currently designed to withstand only about 30 centimeters of sea-level rise by 2050. A new plan is in the works to protect against a rise of up to three meters, but it has yet to be approved. That ‘new coastal vision’ proposes, among other things, widening the beaches.

That might seem sufficient, but the measures in the current coastal plan do not leave us particularly well prepared for what we could face by 2050.

“In fact, measures are already needed by 2030, especially in the ports,” says Ward Van Roy, a marine researcher at the RBINS (Royal Belgian Institute of Natural Sciences) and co-author of the risk analysis.

According to Van Roy, major gaps in coastal protection remain. “And that is precisely what we wanted to highlight with this report: policymakers need to realize that there is still a great deal of work to be done – and that it cannot wait.”

Biodiversity

Water temperatures have been rising for decades. This past summer, the most severe marine heatwave ever recorded – lasting 87 days – took place. As seawater warms, several fish species, such as cod, herring, and plaice, are moving to cooler waters.

Biodiversity in Belgian coastal waters has changed fundamentally over the past few decades due to global warming. Typical cold-water species, such as brown shrimp, gobies, and herring/sprat, are now far less abundant. At the same time, other species – sometimes undesirable ones, like the venomous lesser weever and comb jellies – are thriving.

Combined factors

In the Belgian part of the North Sea, many sectors – shipping, fishing, offshore wind energy, sand extraction, coastal protection, tourism, defense, and nature conservation – must coexist within a 3,456-square-kilometer area, representing 11 percent of the total territory.

“Climate risks rarely occur in isolation,” Van Roy emphasizes. “Sea-level rise, ocean warming, and ocean acidification drive multiple risks simultaneously.  Moreover, they compound the significant pressure already exerted by the many human activities in our North Sea region. As a result, these effects can accumulate.”

The report emphasizes that climate and environmental risks must therefore be assessed alongside other human-related factors that pressure the marine environment.