Green Roofs Are Great. Blue-Green Roofs Are Even Better

[ Courtesy of De Dakdokters Below that stretches a filter layer, which keeps the soil from getting into the next layer, a lightweight crate system that stores the water. And finally, below that you’ve got additional layers to keep water and plant roots from infiltrating the actual roof. “You have, in fact, a flat rain … Read more

Mexico City’s Metro System Is Sinking Fast. Yours Could Be Next

[ Solano‐Rojas and his colleagues found subsidence in the area of an overpass near the Olivos station, which collapsed in 2021 while a Metro train was traveling over it. “We did part of this analysis before 2021, and we detected that that area was having differential displacements,” says Solano‐Rojas. “We were like, ‘Oh, yeah, it … Read more

Cities Aren’t Prepared for a Crucial Part of Sea-Level Rise: They’re Also Sinking

[ Fighting off rising seas without reducing humanity’s carbon emissions is like trying to drain a bathtub without turning off the tap. But increasingly, scientists are sounding the alarm on yet another problem compounding the crisis for coastal cities: Their land is also sinking, a phenomenon known as subsidence. The metaphorical tap is still on—as … Read more

Spain’s Tragic Tower Block Fire Exposes the World’s Failing Fire Regulations

[ On February 22, a fire swept through a 14-story apartment block in the Campanar neighborhood of Valencia, Spain. Ten people died in the blaze. Smartphone footage showed an awning on a seventh-floor balcony catching fire at around 5:30pm CET, before the flames rushed upwards. Within 15 minutes, the entire building was engulfed, aided by … Read more

The City of Tomorrow Will Run on Your Toilet Water

[ Epic Cleantec’s soil amendment Photograph: Matt Simon Researchers are experimenting with using the same technique for wastewater solids, basically turning sludge into a solid product. “If you do pyrolysis—because it’s thermochemical, it’s a heated process—you kill these bacteria, kill these pathogens, kill these viruses. It’s much cleaner,” says engineer Fengqi You, who studies wastewater … Read more