More than 50% of the world's population now lives in urban areas and, in recent years, many major cities have been hit with extreme weather events due to the effects of climate change, like the flooding that hit the London underground - and Queen guitarist Brian May's basement - in the summer of 2021. A key reason for this might be that the urban environments themselves are exacerbating the heating effect, as Verner Viisainen heard from Iain Campbell, from the organisation RMI and the lead author of a new United Nations guide on cooling down cities... Like this podcast? Please help us by supporting the Naked Scientists