The Mekong Delta is home to 17 million people and is Vietnam’s most productive agricultural region. An international group of scientists warn this week that almost all of the low lying delta will have sunk beneath the sea within 80 years without international action. Its disappearance is the result of both sea level rise and developments such as dams and sand mining.

Also in the programme: using the rumbling 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