The Rising Tide: Challenges of Sea Level Rise

Rising sea levels are the most harmful consequence of climate change

«Sea level rise is an existential threat to Pacific islands. The issue with sea level rise starts at the shore. It seeps into the water table. It infiltrates clean water. People don’t have clean water to drink. Livestock doesn’t have clean water to drink. Agriculture irrigation systems can’t rely on clean water. So it’s kind of this domino effect of  devastation.»

Ambassador Seid was key note speaker at Seabed Curtain Project's session at the Nordic Pavillion at COP28.
The Palauan Ambassador to the UN, Ilana Seid, was a key note speaker at the Seabed Curtain Project's session during the Nordic Pavillion at COP28.

Rising sea levels are one of the most urgent consequences of climate change, posing serious threats to coastal communities around the world. As oceans encroach on land, cities face more frequent and severe flooding, damaging homes, roads, and vital infrastructure. Saltwater seeps into freshwater supplies and farmland, threatening food security and clean water access.

Millions of people living in low-lying areas risk displacement, creating waves of climate migration and social disruption. Public health is also at stake, with increased exposure to waterborne diseases and mental health stress. Economically, the costs of damage and adaptation are immense, while natural ecosystems like wetlands and coral reefs—crucial for storm protection—are being lost.

Each meter of sea level rise will force about 200 million people across the world to relocate, with economic costs of $300-1000 billion per year per meter of sea level rise, depending on socio-economic pathway.

Rapid ice loss due to rising ocean temperatures and deep-water currents will equally alter or destroy habitats and reduce biodiversity. Coral reefs suffer bleaching due to warmer oceans, and polar species lose their ice-based habitats and are forced to migrate. However, not all species can and will respond quickly enough, move far enough, or find new environments or habitats and adapt quickly enough to survive.

Cooling the Earth alone is unlikely to prevent catastrophic sea level rise. Parts of the Greenland and Antarctic ice sheets, such as the Thwaites glacier, are susceptible to Marine Ice Sheet Instability (MISI), where unfavorable geometry leads to runaway ice loss. This loss is calculated to occur with tipping point temperatures close to present day. Once MISI begins, the system becomes disconnected from external forces such as greenhouse gas warming, and ice loss becomes a function of geometry, lowering the planetary albedo and exacerbating the rising ocean temperatures.

However, nature has stabilization processes that could be encouraged or promoted through skillful human intervention.

Learn more about our project
The loss of ice in Greenland and the shrinking of glaciers in other parts of the Arctic currently contribute up to 40% of the current 3,4 mm global sea level rise per year. Photo by Peter Prokosch via Grid Arendal

Quick facts about rising sea level

200 million people per year will have to relocate with each meter of sea level rise. More than 300 million people live in 20 coastal megacities. 

There will be $300 billion – $1000 billion in annual spending to combat flood damages per meter of sea level rise.

It is estimated that seabed anchored curtains could save ~$2 trillion by the end of the century.

One simulation showed seabed curtains could delay ice collapse by 100 years and evade half a meter of sea level rise.