At the beginning of the 19th century, Chicago had a problem: the city was only slightly higher in elevation than Lake Michigan, which caused sewage and other runoff to pool at the centre of town, leading to smelly living conditions and numerous disease outbreaks. To solve it, engineers physically raised the city — buildings, streets, sidewalks and all — and installed a citywide sewage system. This is the power of human ingenuity, and it offers a lesson in how we can tackle some of the world’s most intractable problems, such as climate change.
