The climate crisis has arrived, and coastal cities are at the frontline of the climate emergency. Rising sea levels, extreme weather events, and warming temperatures are amplifying the danger to city residents who already face a myriad of existing social, economic, and political vulnerabilities. Together, these cascading issues can undermine a city’s physical infrastructure, its economy, and food, energy, and water security. This is especially important for cities experiencing rapid urbanization. Without concerted action, these impacts have the potential to overwhelm a city’s capacity to respond to the threat posed by climate change.