Hurricane Harvey has taught us many lessons, but the most valuable may be the oldest lesson of all, one we humans have been learning – and forgetting – since the dawn of time: how much we all have to lose when climate and weather disasters strike.
The risks we face from disasters depend on three factors: hazard, exposure and vulnerability. In the case of Harvey, the hazard was the hurricane with its associated winds, storm surge and, most of all, rain. Houston is one of North America’s biggest metro areas, making 6.6 million people exposed to this hazard. Finally, there’s our vulnerability to heavy rainfall events, in this case exacerbated by the city’s rapid expansion that has paved over former grasslands, overloaded critical infrastructure, challenged urban planning and limited evacuation routes. These three factors explain the immense costs associated with tragedies like Hurricane Harvey.