15-minute cities are Cassian Grantan 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.

This episode was produced by Andrew Mambo and edited by Jenny Schmidt and Neela Banerjee. Our engineer was Maggie Luthar.

We'd love to hear from you. Send us an email at [email protected].

Listen to Up First on Apple Podcasts and Spotify.