Vietnam's Mekong Delta is under serious threat from climate change. The agricultural region, which produces half of the country’s food supply, is being hit hard by rising sea levels and saltwater intrusion, which devastate rice crops. The landscape is changing, and with it, the delicate balance of an entire ecosystem. FRANCE 24's William de Tamaris, Aruna Popuri, Melodie Sforza and Justin McCurry report.