On the evening of September 1, three days after Hurricane Ida in Louisiana, the remnants of the storm rolled over New York City, pouring more than five inches of water onto the metropolitan area in a matter of hours. The subsequent flood event left thousands of cars on the streets, spat water into countless basement apartments and paralyzed almost the entire subway network. At least 13 people died in the city alone.
Corresponding Data from NOAA, the event in Ida was classified at least as a “centenary flood”, which means that it has a probability of about 1 percent in a given year. However, the event came only a few weeks after another, one-time flood; That storm broke New York’s one-hour record for precipitation at 1.94 inches, but the Ida event broke that record again, bringing 3.14 inches of rain to Central Park in a single hour.
Descriptors like “hundred year flood” are not just terms used in art. They reflect how we understand and interpret nature, and when we witness events like Elsa and Ida, we can be sure that our understanding is painfully out of date. If we want to catch up with such disasters, we have to come to terms with the fact that all we need is a radical, comprehensive transformation of the world in which we live; to survive we may have to change it beyond recognition. We need to rethink how we build, live and do almost everything, and rebuild most of the physical environment that we take for granted.
Many of us think of climate change as something that happens in specific, defined areas: fires burn in California; Cyclones hit Florida; Heat waves are scalding the Arizona deserts. If it didn’t do anything else, last summer showed that this framework is wrong. The temperate Pacific Northwest burned under a heat dome, an apocalyptic flood raged through the hills of Middle Tennessee, and the Caldor Fire jumped over the Sierra Nevada and burned through Lake Tahoe.
The increase in extreme rainfall is particularly noteworthy as it threatens many of the northern cities we consider havens from climate change. Warmer air can hold more moisture, which means that storms that pass that air can pool and give off more rain. This phenomenon is behind the convective weather patterns known as “rain bombs,” and while science is still unsure, it appears to affect larger storm systems like Ida and the rainstorm that hit Tennessee.
The sheer territorial expansion of areas exposed to extreme weather conditions has devastating consequences: it is now difficult to know where and how to concentrate our resources, and it is almost impossible for the later victims to prepare for the impact. The Federal Emergency Call Center publishes a nationwide database with Flood zone maps which purport to show which areas are threatened by flooding. If you look at the maps for New York City, you’ll find that they bear almost no resemblance to the places where floods occurred during Ida: elevated parts of Brooklyn like Bushwick, Bed stuy, and Park slope were buried under several meters of water. The folly of the flood maps is the same as the folly of the Centennial Flood: they are both attempts to delineate and define a crisis that seems to have no real outer boundary.