The enchanting scene along the banks of Munich's lime-green Isar River on a recent summer afternoon made me, an out-of-towner, shiver with envy. Clusters of students, off-duty office workers, families, and naked sunbathers were sprawled out on blankets with bottled beer and light meals. Every now and then a swimmer or a walrus would pass by, carried away by the swift current. In 2000, before the climate crisis accelerated and summers turned into hardships punctuated by a multitude of  temperature records , the city of Munich has undertaken a major restoration of the Isar River, which flows north from the Alps through the city center and into the Danube. An 11-year effort worth 38 million dollars  It included cleaning the waters of the Isar, expanding its floodplains, and adjusting the banks to accommodate the rapid spring snowmelt. (Paul Hockenos)