100 MILLION BUILDINGS UNDER WATER: THE PRICE OF GLOBAL WARMING

Even a moderate rise in sea levels threatens millions of homes and critical infrastructure across Africa, Asia, and Latin America, warn researchers from McGill University.
A large-scale study by McGill University has shown that rising sea levels due to global warming could lead to the flooding of up to 100 million buildings in countries of the Global South. Scientists conducted a detailed analysis using satellite data, assessing the vulnerability of every single structure in regions of Africa, Southeast Asia, and Central and South America.
Even under optimistic scenarios, where the ocean level rises by only half a meter, up to three million homes would be submerged. Under a scenario of uncontrolled greenhouse gas emissions, this number could rise to 100 million.
“Sea-level rise is a slow but inexorable consequence of global warming,” said Professor Natalia Gomez, a co-author of the study. “If humanity does not reduce the use of fossil fuels, entire coastal communities could disappear under water.”
According to Professor Geoff Criddle, even a small rise in ocean levels can lead to devastating consequences due to terrain features: “We were struck by the sheer scale of the risk—some countries are especially vulnerable even to small changes.”
The researchers also created an interactive map using Google Earth Engine, allowing policymakers and urban planners to identify the most vulnerable areas and develop adaptation measures—from building protective seawalls to revising city planning.
Lead author Maya Willards-Stepan emphasized: “It’s no longer possible to avoid sea-level rise, but how devastating the consequences will be depends on the speed of our actions.”
The scientists warn that the effects of flooding will not be limited to coastlines; disruptions to ports, transport networks, and food supply chains could trigger new waves of global crises, impacting the economy and food security worldwide.