Paul Hockenos writes:

The mesmerizing scene along the banks of Munich’s lime-green Isar River on a recent summer afternoon made me, an out-of-towner, quiver with envy. Clusters of students, off-duty office workers, families and nude sunbathers were sprawled out on blankets with bottled beer and light meals. Every so often, a swimmer or tuber passed by, carried by the swift current.

In 2000, before the climate crisis accelerated, turning summers into slogs punctuated by a slew of heat records, the city of Munich undertook a sweeping restoration of the Isar, which flows north from the Alps through downtown and into the Danube. The 11-year, $38 million endeavor involved purifying the Isar’s waters, expanding its floodplains and modifying its banks to accommodate the torrential spring snowmelt.

The restoration was meant to benefit flood-prone neighborhoods, as well as the river’s flora and fauna. But today the river is also an easily accessible public space that offers essential relief from the heat. “I don’t have a balcony, I don’t have a garden, but I have the Isar,” said an apartment-dwelling friend who swims there regularly.

Urban residents everywhere deserve the same opportunity. If cities around the world invest in cleaning up their waterways, they will create crucial lifelines to make the hottest months more bearable in environments hit disproportionately hard by global warming. Paved surfaces absorb heat, and buildings and narrow streets trap it, putting city populations more at risk than rural ones. Healthy rivers are just the kind of “green infrastructure” cities need — ecosystems that significantly enhance the quality of urban life. [Continue reading…]