Is Climate Change Responsible for Flooding in the Northeast?

Heavy rain events of more than two inches have become more common, according to current data. Whether it’s because of climate change or not is up for debate, but what’s not is that mitigation is necessary.

by Jim McKay / November 14, 2019

Wildfires in the western part of the United States, flooding there and elsewhere, including the Northeast. Climate change manifests itself differently, depending on the region and season. In the Northeast, heavy rain events of more than two inches of precipitation have become common, and that has officials talking, not only about what to call it but what to do about it.

In Utica, N.Y., Mayor Robert Palmieri doesn’t mince words when surveying flood cleanup. “I know no one wants to talk about climate change,” he told the Observer-Dispatch in Utica. But the rainstorms that we’re having at this point, where we used to get them once every maybe five years, we’re getting them once every two years, sometimes twice a year.”

Jessica Spaccio, a climatologist at the Northeast Regional Climate Center at Cornell University, confirmed what Palmieri said. “Climate change is definitely contributing to what we’re seeing in regard to the flooding,” she said. “Now extreme precipitation and flooding are two separate things, although closely related.”

She explained that it could be a really wet month where not as much of a downpour is needed to cause a flood. Or it could be a really dry month where a big downpour doesn’t cause a flood. “It depends also on things like development, and size of culverts,” she said. “Flooding is a complicated issue, there’s a lot that goes into it.”

But precipitation has increased, and extreme precipitation events are definitely occurring more often in the Northeast, she said. “it’s something we’re seeing already, and we expect it to continue with climate change.”

What used to be considered a 100-year event, for instance, could now be considered an 80-year event. The more intense rain events are occurring more often with more precipitation in them. A national climate assessment done in 2014 found that during the heaviest rain events between 1958 and 2012, there was a 71 percent increase in the amount of precipitation during the heaviest 1 percent of rain events.

David Nicosia, a warning coordination meteorologist for the National Weather Service in Binghamton, N.Y., cautioned against calling “heavy rain events” the result of climate change. He told the Observer-Dispatch that, “climate is long-term,” and even the trend of more extreme rainfall events could change.

“That can be true,” Spaccio said. “If someone doesn’t want to talk about climate change that’s fine, but we’re still seeing an increase.”

And officials in the Northeast are beginning to acknowledge that and prepare for the future with data suggesting more rainfall. “A lot of people are starting to really look at data and try to prepare more,” Spaccio said.

The biggest change is the use of current data, which suggests more rainfall, instead of data gleaned during the 1960s, and using that data to take into consideration intensity-duration frequency of recent storms.

Mayor Palmieri said he is hoping state-funded mitigation studies will come up with solutions for the future. “What is going to be our best process moving forward? How can the state help us with infrastructure? Is it infrastructure, is it maintenance, or a combination of both?”

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