Can Tho
Capital of Vietnam's rice bowl, three metres above sea level, where saltwater intrusion threatens the delta that feeds 100 million people.
The Mekong Delta produces over 50% of Vietnam's rice and 80% of its rice exports. Can Tho is the delta's capital — the logistics, processing, and distribution hub for a region that feeds 100 million Vietnamese and contributes to global food security. The city sits three metres above sea level.
That elevation defines everything. The 2016 El Niño pushed saltwater over 100 kilometres upstream into the delta, damaging 160,000 hectares of rice paddies and causing over $650 million in losses. This was not an anomaly. Saltwater intrusion events are increasing in frequency and severity, and projections suggest 22-45% of the delta's agricultural land could be affected by salinity within a decade without major intervention.
Can Tho sits three metres above sea level at the centre of a rice bowl that feeds 100 million people — and saltwater is moving inland.
The city's famous floating markets — particularly Cai Rang, operating for over a century — are now more tourist attraction than commercial infrastructure. Road networks have replaced river commerce for most goods distribution, leaving only 2 of the delta's 10 major floating markets economically significant. Tourism contributes roughly 6% of Can Tho's economy; rice is existential.
The phase transition facing the delta is non-linear. Small increases in sea level do not produce proportionally small losses in agricultural output. Instead, saltwater intrusion follows tipping-point dynamics: once salinity reaches a threshold in irrigation channels, entire crop cycles fail simultaneously. The delta does not gradually become less productive — it flips between freshwater agriculture and brackish marshland, with little middle ground.
Can Tho is growing fast — ranked among the world's fastest-growing urban areas by population — absorbing rural migrants displaced by the same salinity that threatens the city's economic foundation. The mangrove parallel is exact: mangrove forests thrive at the boundary between salt and fresh water, but only within a narrow salinity range. Push past the threshold, and the entire ecosystem state-shifts. Can Tho's rice economy operates on the same knife-edge, buffering a nation's food supply from a position that climate change is steadily undermining.