This paint could cool your home and harvest water from the air | CNN

EDITOR’S NOTE: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, together with the solutions. Rolex’s Perpetual Planet Initiative has partnered with CNN to drive awareness and education around key sustainability issues and to inspire positive action. As global temperatures rise and water scarcity worsens, a nanoengineered paint developed by researchers in Australia aims to tackle both — with the stroke of a brush. For University of Sydney scientists Chiara Neto and Ming Chiu, these growing pressures sparked an idea: a rooftop coating that could cool buildings and harvest water from the air. That work evolved into startup Dewpoint Innovations, founded in 2022 with ambitions beyond cooling paint to a broader rethink of how infrastructure is designed: If rooftops across a city could reflect heat and collect water, they could become part of the climate solution. In a warming world, cities are becoming heat traps. Concrete and rooftops absorb the sun’s energy, raising temperatures, leading to what’s known as the urban heat island effect — where cities experience higher temperatures. China was already a wind ene