Study: Extreme heat caused by urbanisation, global warming threatening cities

An advertising board showing 47 degrees Celsius amid a heatwave in Seville on Aug 13. Photo: Cristina Quicler/AFP

Rapid population growth and global warming are increasing exposure to extreme heat in cities, aggravating health problems and making moving to urban areas less beneficial for the world's poor, according to a study released recently.

The rise is affecting nearly a quarter of the world's population, said the report published in the Proceedings of the National Academy of Sciences.