Hurricane Ida’s remnants, which killed dozens of people and triggered flash floods across the tri-state area, marked the latest extreme weather event in a summer filled with climate-related disasters.

For Kim Cobb, who co-authored a landmark United Nations scientific report on climate change, the intensity of the storm served as another reminder of how human activity has fundamentally altered the Earth’s atmosphere.

“We are moving into uncharted territory with climate change,” said Cobb, director of the global change program at Georgia Tech. “The climate we’ve been living in, is not going to be the climate we are living in right now, nor over the next decades.”

The weather spawned by the remnants of Hurricane Ida brought record rainfall across the region. Newark, New Jersey, saw 8.41 inches of rain Wednesday, making it the rainiest day on record. In New York City, 3.15 inches of rain fell in a single hour, more than at any point in the city’s records, dating back to the 1800s. Central Park alone, nearly doubled its previous record for rainfall set in 1927, according to the National Weather Service.

“These rains were record breaking by a long shot. It reminds me of the kind of shattering heat waves that we saw in the Pacific Northwest, earlier this summer,” said Cobb. “It’s just jaw dropping.”

Cobb’s research, included in the UN report released by the Intergovernmental Panel on Climate Change makes clear the frequency of Hurricane Ida-like events and the intensity witnessed across the Gulf Coast to the Northeast this week will only increase, regardless of climate action taken now. With global temperatures likely to rise around 1.5 degrees Celsius within the next 20 years, the blistering heat waves and wildfires, as well as torrential rain and flooding will only escalate with each additional increment of warming, Cobb said.

The fallout from the most recent storm has already raised questions about the resilience of the U.S. transportation system and broader infrastructure and its ability to withstand extreme weather events. Flood waters overwhelmed New York City’s train system, passengers were stranded, and New York Mayor Bill de Blasio had to urge residents to stay off the roads and subways. In an interview with CNBC, Janno Lieber, the acting chair and CEO of New York City’s Metropolitan Transportation Authority (MTA), said the system was in desperate need of upgrades.

“We really have to work with our friends in the city government to make sure that the street-level drainage is a little more at capacity so we don’t, in these new climate change-era flash-flooding situations, get as much coming down into the subway system,” said Lieber.

President Joe Biden echoed that sentiment.

“To the country, the past few days of Hurricane Ida and the wildfires in the West and the unprecedented flash floods in New York and New Jersey is yet a reminder that these extreme storms and the climate crisis is here,” said Biden. "We need to act."

The infrastructure bill moving through Congress allocates millions of dollars to upgrade subway systems and roads. Local, state, and federal lawmakers have vowed to cooperate and invest in climate resilience, to build out reinforcements in preparation for future climate events. But Cobb said their options may be limited, given the pace of the warming, and the changes.

“There are limits to how much this infrastructure can adapt to weather a storm like this, and that points to the need to enact the kind of deep and sustained emissions reductions that will limit future climate risk and loss by mid century,” she said. “We have locked in another couple tenths of degrees Celsius, but our choices in the next 10 or 20 years, will determine how hot it gets by mid-century.”

Akiko Fujita is an anchor and reporter for Yahoo Finance. Follow her on Twitter @AkikoFujita

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