Editor’s Note (10/16/19): This article has been edited after posting for inclusion in the November 2019 issue of Scientific American.
A stunning 12 million people could be forced to retreat from rising seas in Vietnam’s Mekong Delta within half a century. Geographer Philip Minderhoud and his colleagues at Utrecht University in the Netherlands arrived at this conclusion after analyzing ground-based topography measurements to which outside scientists’ access was limited for years. The new analysis, published in August in Nature Communications, shows that the Mekong’s elevation above sea level averages just 0.8 meter—almost two meters lower than commonly cited estimates.
