15-minute cities are an urban planning idea growing in popularity. The idea is that you can get to the key places in your life - think work, education, food, recreation - in a 15-minute walk, bike or transit ride. Now mayors from Paris to Cleveland are looking to use them to reduce planet-heating car pollution and improve quality of life.But they face obstacles - from NIMBYs, to public schools, to death threats for urban planners and politicians. Reporter Julia Simon talks about her months-long reporting on a climate solution that has become a lightning rod for conspiracy theories. This reporting is a part of NPR's climate week.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy