Sea Level Rise Threatens 100 Million Buildings, McGill Study Warns

A recent study led by researchers at McGill University reveals that over 100 million buildings in the Global South face significant risk from rising sea levels if fossil fuel emissions are not rapidly curtailed. Published in the journal npj Urban Sustainability, the research provides a comprehensive assessment of how long-term sea level rise could affect coastal infrastructure across regions including Africa, Southeast Asia, and Central and South America.

The study utilized advanced satellite mapping and elevation data to project the number of buildings that could be submerged at various levels of sea level rise over centuries. According to Prof. Natalya Gomez, a co-author of the study and Canada Research Chair in Ice Sheet–Sea Level Interactions, “Sea level rise is a slow, but unstoppable consequence of warming that is already impacting coastal populations and will continue for centuries.”

Significant Risks Even at Minimal Sea Level Rise

The research considered scenarios ranging from 0.5 metres to 20 metres of sea level rise. Alarmingly, even a modest rise of just 0.5 metres, which could occur under ambitious emissions reduction efforts, could inundate approximately three million buildings. In contrast, projections indicate that a rise of five metres or more is possible within a few hundred years if emission trends continue. Under such scenarios, the risk escalates dramatically, potentially endangering over 100 million buildings.

Many of these structures are located in densely populated, low-lying areas. The implications are dire, as entire neighbourhoods and vital infrastructure—including ports, refineries, and cultural heritage sites—would be at risk. “We were surprised at the large number of buildings at risk from relatively modest long-term sea level rise,” stated Prof. Jeff Cardile, another co-author of the study.

Implications for Urban Planning and Policy

The findings serve as a crucial warning for urban planners, policymakers, and communities preparing for the inevitable impacts of rising sea levels. Eric Galbraith, a professor involved in the study, emphasized that “Every one of us will be affected by climate change and sea level rise, whether we live by the ocean or not.” He noted that disruptions to coastal infrastructure could severely impact the global economy and food systems, as many essential goods and resources are transported through affected ports.

To aid in strategic planning, the study includes an interactive map that is accessible via Google Earth Engine. This tool allows decision-makers to visualize areas with the highest exposure to rising sea levels. The data can inform climate adaptation strategies, such as constructing protective infrastructure, modifying land use planning, or, in some cases, implementing managed retreat.

Lead author Maya Willard-Stepan, who conducted the study as part of an undergraduate research project, remarked, “There is no escaping at least a moderate amount of sea level rise. The sooner coastal communities can start planning for it, the better chance they have of continuing to flourish.”

This comprehensive study sheds light on the urgent need for proactive measures to safeguard vulnerable communities from the ongoing threat of climate change and rising sea levels.