Vietnam’s vast Mekong Delta faces an uncertain future. Also in the programme: using the rumble of traffic in Mexico City to monitor earthquake hazard, record-breaking quakes on Mars and a record-breaking high jumping robot.
Photo: Mekong River in Kampong Cham, Cambodia
Credit: Muaz Jaffar/EyeEm/Getty Images
Presenter: Roland Pease
Producer: Andrew Luck-Baker