"Rising Seas, Rising Stakes" by Soojin Nam

The ocean has always been in motion, but the changes seen in recent decades have gone beyond natural cycles that have lasted for centuries. Since the late 1800s, the global average sea level has risen by more than 20 centimeters, a speed not seen in thousands of years. Once regarded as a distant environmental concern, sea level rise has now become a pressing issue felt within a single generation. Satellite data from the past 30 years shows a curve that continues to rise, and its slope is becoming steeper.

The main drivers behind this rise are twofold. The first is thermal expansion, where seawater expands as it absorbs excess heat from the atmosphere. The second is the melting of land-based ice, which includes glaciers in high mountain ranges as well as the massive ice sheets of Greenland and Antarctica. These two processes release vast amounts of water into the ocean, reshaping coastlines and encroaching upon low-lying areas. In the early 1990s, the sea level was rising by about 2 millimeters per year, but that rate has now more than doubled to over 4 millimeters annually. Scientists warn that without significant reductions in greenhouse gas emissions, this trend could continue for centuries.

The impacts extend far beyond shoreline retreat. Flooding events that once occurred only during severe storms are now happening during ordinary high tides in many coastal cities. Saltwater seeps into underground freshwater reserves, threatening drinking water supplies, while ports, roads, and wastewater treatment facilities face increasing risk. In some island nations, entire communities have begun to relocate, marking some of the earliest examples of large-scale climate migration.

Economic damage is also becoming evident. Coastal towns that rely on tourism see their income shrink when beaches erode or are damaged by storms. Mangrove forests and coral reefs, once home to diverse marine species, are now being submerged in deeper water, reducing fish stocks. In flood-prone regions, property values drop, limiting residents’ economic options.

Addressing this problem requires both global cooperation and local action. On the global scale, reducing greenhouse gas emissions is the most effective way to slow sea level rise. This means transitioning to renewable energy, improving energy efficiency, and protecting carbon sinks such as wetlands and forests. At the local level, adaptation strategies are essential. Building seawalls, elevating roads and buildings, and restoring dunes and wetlands can help reduce wave energy and prevent flooding. Some cities are redesigning urban landscapes with green spaces that absorb water to better withstand heavy rainfall and tidal flooding. Early warning systems and evacuation plans save lives during extreme events.

One of the most promising approaches is restoring coastal ecosystems. Mangrove forests, salt marshes, and seagrass meadows not only shield shorelines from waves but also store large amounts of carbon. This provides both flood protection and climate change mitigation.

Sea level rise is not a problem for a single nation or region but a reality facing all of humanity. Large or small, wealthy or poor, every community will feel its effects. However, with a combination of emission reductions, adaptation measures, and active community participation, we can meet this challenge together. The seas are rising, but so too can our determination to respond.