CNN  — 

When Superstorm Sandy wreaked havoc on parts of the Northeast in 2012, it exposed the dire need to strengthen New York City’s infrastructure to adapt to what was then a looming threat of the climate crisis.

Nearly a decade later, the city is picking up the pieces after another climate whiplash it was unprepared for. Within two weeks, two storms – Henri and Ida – broke rainfall records in the Northeast. Flash flood emergencies from the remnants of Hurricane Ida stretched for 190 miles from Philadelphia to New York City. Central Park recorded its wettest hour on record, while Newark, New Jersey, recorded its wettest day. As of Friday, the floods had killed at least 46 people in the region.

“This was worse than Sandy, and it happened over a short period of time,” Maria Lopez-Nuñez, a resident of Newark, told CNN. “And sadly, our region is not more prepared than when Sandy hit.”

When the remnants of Hurricane Ida dumped more than 7 inches of rain on parts of New York City, officials and meteorologists seemed stunned by the devastating flooding that ensued.

“This is the biggest wake-up call we could possibly get,” said New York City Mayor Bill de Blasio. “What we have to recognize is the suddenness, the brutality of storms now. It is different.”

But climate scientists have warned for years that the more humans heat up the planet, these sorts of extreme rainfall events will occur with increasing frequency and intensity. And in many parts of the country, the infrastructure in place today was built for a climate that no longer exists.

climate heavy precipitation events

From the deadly heatwaves that scorched the Pacific Northwest to the damage strewn by Ida from Louisiana to New York, these floods are the latest in a string of events that have laid bare just how poorly equipped America is for what climate change has in store.

Climatologist Kim Cobb, director of the Global Change Program at the Georgia Institute of Technology, warned that New York, like many cities, was clearly not prepared to deal with climate-related and weather disasters such as Storm Ida.

“I don’t think that what we’re seeing today is emblematic of a climate-ready city in New York and, obviously, we have a story coming out from cities across the world — from communities out west grappling with wildfires that are linked to climate change,” Cobb told CNN.

“We’re just coming out of Ida’s devastation across the southeast US – Louisiana and Mississippi – infrastructure that is not ready for our climate of now, let alone the climate of tomorrow. These kinds of climate impacts are going to worsen with each additional increment of warming.”

Climate adaptation won’t be easy — or cheap

Cars sit abandoned on the flooded Major Deegan Expressway in the Bronx, New York, following a night of heavy wind and rain from the remnants of Hurricane Ida.

As other extreme flooding events have shown — like Hurricane Harvey’s record-breaking slog across Texas and Louisiana in 2018 — when huge amounts of rain are dumped on expanses of concrete and pavement, it can be a recipe for disaster, said Philip Orton, a professor of ocean engineering at Stevens Institute of Technology.

When torrential rains fall on these impermeable surfaces, there is simply nowhere for the water to go but into overloaded storm drains. In the case of New York, floodwaters also spilled onto subway platforms and, tragically, into basement apartments, where many victims were trapped.

On Friday, Mayor Bill De Blasio announced a new series of initiatives geared toward alerting and evacuating residents from vulnerable basement apartments ahead of future storms.

Orton said urbanization is likely part of the reason for the devastation seen across the Northeast.

But many of these areas were paved over decades ago. What has changed in the years since is the climate, Orton said.

Extreme rainfall rates such as the one Henri and Ida exhibited — as well as other recent deadly flooding events in Tennessee, Germany and China — are happening more frequently due to human-caused climate change.

A recent UN climate report stated, “the frequency and intensity of heavy precipitation events have increased since the 1950s over most land area.” That’s especially true in the US, where the heaviest downpours seem to be increasing in all regions of the continental US, with the Northeast region showing the largest increase, according to the US National Climate Assessment.

“People focus on the hurricanes, but the truth is that extreme rain, which can come in the aftermath of a hurricane, like what happened with Harvey and Ida, are the events that we need to be designing for,” Laura Clemons, a certified floodplain manager who formerly advised the New York City Housing Authority on resilience strategies, told CNN.