By themselves, the young trees lining a still barren boulevard in Vienna’s newest neighborhood hardly look like climate warriors. Planted earlier in the year, the American ash and Bosnian maples were still scraggly enough by late July that they didn’t make a dent in the near-100o F temperatures. But as the visible part of the Austrian capital’s first “sponge city,” those trees, and the ingenious underground planters in which they grow, will soon play an important role in mitigating some of climate change’s worst effects. Most cities today are not built to handle the kind of extreme weather that climate change inflicts. Sponge cities provide one solution. Urban designer Yu Konjian first articulated the idea in 2012 after flooding wreaked havoc on dozens of cities in his native China. Instead of paving over the land with impermeable concrete and asphalt, he proposed adding green spaces that could act like sponges and absorb excess rain water. Instead of a “gray” infrastructure of pipes and dams that whisk water away from the city and dump it into rivers or the sea—systems that are prone to overflowing during storms and wearing out with time—sponge cities would use simple gravity to channel water steadily into soil where it could support plant life, or into reservoirs where it could be stored and repurposed. In other words, the sponge city would replicate the natural water cycle. Tap the link in our bio to read more about the new neighborhood in Vienna that is intended to protect residents from the extreme weather inflicted by climate change. Photographs by @ingmarbnolting for TIME