What’s in store for New York City because of climate change?

New projections from the New York City Panel on Climate Change (NPCC) confirm that the city will be hotter, rainier and wetter in the coming years — with major shifts hitting the city in the 2030s, less than a decade away.

The NPCC’s latest estimates, for example, project sea levels around the city to continue to rise between half a foot and just over a foot in the 2030s. Annual precipitation is expected to increase by up to 10% in those years, while the city could experience temperatures between 2 and 4.7 degrees warmer. 

The estimates are part of a forthcoming paper from the NPCC Climate Science Working Group and were reviewed during a presentation to a northeast climate consortium earlier this month.

First convened in 2008, the NPCC is a group of 20 climate experts who advise policymakers on the latest science and strategies to address hazards facing the boroughs. The panel has come out with four comprehensive reports since 2010, and is expected to release its fifth in April. 

The latest projections are fairly consistent with the previous estimates, which experts say underscore the urgency of protecting New Yorkers.

“The direction of the change and the general magnitude of those changes are very constant,” said Luis Ortiz, a climate scientist and professor at George Mason University, who worked on the report. “Things are going to get hotter and relatively wetter… We need to prepare, and we need to adapt now to get ready for those changes.”

The new predictions will inform the city government’s planning, policies and programs, including how to design projects and where to locate them, according to the Mayor’s Office of Climate and Environmental Justice.

Given what’s to come, the work can’t happen fast enough, said Klaus Jacob, a Columbia University geophysicist who previously served on the NPCC.

“The city is moving in the right direction,” he said, “but compared to how the weather and climate is changing, it’s a snail’s pace, and the climate is a rabbit.”

‘A Huge Problem’

The sea levels around New York City have already risen about a foot since 1900, a higher rate than the global average.

The NPCC expects sea levels around the city to continue to rise at least another foot — or up to almost two feet — by the 2050s. The range has to do with the amount of planet-warming gas emitted into the atmosphere.

“We don’t know, really, which carbon emissions or greenhouse gas emissions pathway we’re on,” Ortiz said.

Slashing emissions on the global scale could lead to the lower end of the projections, he said.

Compared to previous projections, the NPCC’s newest estimates anticipate less sea level rise in  a high gas emissions scenario, but a greater  sea level rise under models that assume  less  emitted gas.

For instance, previous NPCC estimates projected half a foot to 2.5 feet of sea level rise in the 2050s, compared to the latest estimates of one foot to two feet for the same period.

Higher seas mean worse storm surges and more frequent flooding during high tides.

“This is a huge problem,” said Amy Chester, managing director of resiliency nonprofit Rebuild By Design.

She pointed out how floodwaters overtopped parts of coastal Manhattan earlier this month because of storm surge and high tides.

“Just imagine that we have another two feet, even if it’s the lowest [estimate] — it wouldn’t even be overtopping, it would just be topped 100% of the time,” she said, noting the new estimates of at least two feet of sea level predicted by 2100.

More Rainy Days

The NPCC’s new estimates also predict average annual precipitation will increase up to 10% by the 2030s, 14% by the 2050s and up to 30% by 2100. 

That means more frequent extreme rain events, similar to September 2021’s Hurricane Ida, as well as stronger rainstorms in general.

Scientists said there are some unknowns about drought risk, and those questions have to do with possible changing demand for drinking water, as well as evaporation caused by higher temperatures.

Global warming means New York City will also get hotter. It already has: average temperatures at Central Park, for instance, have risen a quarter of a degree per decade since 1900 — meaning the city is about 3 degrees warmer than it was during the Gilded Age.

Temperatures citywide are predicted to increase between two and 4.7 degrees by the 2030s, and between 5.1 and 13.5 degrees by 2100, according to the NPCC’s new modeling. The estimates for increasing temperatures are slightly higher but not significantly different compared to previous NPCC projections.

Columbia University climate professor and NPCC member Radley Horton explained that rising temperatures mean a greater amount of hot days, longer heat waves and warm weather that comes earlier and lasts longer.

“We know that heat waves pose a variety of greater risks, whether to human health or the risk of blackouts and power failure,” he said during the presentation.

Each year, heat leads to the deaths of an average of 370 people in New York City, though all New Yorkers are not equally vulnerable. And some neighborhoods — those with less trees or that lack a sea breeze — tend to be hotter than others. The projections do not account for such differences in temperature within the city.