EditorialDieter Bartmann, an early Bahnstadt resident, in the newly developed neighborhood that strives to be climate-neutral, in Heidelberg, Germany, Feb. 4, 2021. (Felix Schmitt/The New York Times)
EditorialDieter Bartmann, an early Bahnstadt resident, in the newly developed neighborhood that strives to be climate-neutral, in Heidelberg, Germany, Feb. 4, 2021. (Felix Schmitt/The New York Times)