But should we stay hopeful? Despite the growing risk to millions of people, scientists are finding new ways to protect coastal populations from flooding.
Rising sea level to drown 136 cities

Glossary
Altitude - The height of an object or point in relation to sea level or ground level.
Nasa - The National Aeronautics and Space Administration, responsible for the US space programme.
IMF - The international Monetary Fund. Its main function has been to manage debt difficulties in many countries, often enforcing strict financial discipline in exchange for loans to governments.
Surge Barriers - Floodgates designed to protect coastal areas from flooding caused by storm surges and high tides.