According to a British charity, "Christian Aid", the people of the US, China and India will be at greater risk due to persistent climate changes.
The eight most vulnerable cities on the list are all in Asia and Indian cities Kolkata and Mumbai will be most at risk.
The study says that reducing carbon emissions and limiting global temperature increase will require a transition from fossil fuels to low-carbon energy sources.
The study also calls for international systems to help communities recover from devastating storms and floods.