The data keeps piling up: climate change presents a clear and growing threat to New York City, and now is the time for action.
A new report released today, Building the Knowledge Base for Climate Resiliency, details for the first time projections in sea level rise, temperature, and precipitation for New York City through the year 2100.
Overall, the news is grim: according to the report’s authors, annual temperatures are hot and getting hotter, extreme precipitation events are increasing in frequency, and the sea is rising faster than expected.
The report was produced by the New York City Panel on Climate Change, an independent body of academic and private sector experts that advises the city on climate risks and resiliency. The NPCC was convened by Mayor Michael Bloomberg in August 2008 as part of PlaNYC. This is their third report since that time and presents work from January 2013 to January 2015.
Sea Levels Are Rising, and Fast
Some of the most startling findings from today’s report revolve around sea level rise projections. Since 1900, New York City has seen sea levels rise around 12 inches—that’s nearly twice the observed global rate over a similar time period.
But it’s not going to stop there: this trend is expected to continue, and even accelerate, as the century progresses. According to the report, sea level could rise 11-21 inches by the 2050s, and 18-39 inches by the 2080s. By 2100, it could reach as high as six feet.
Low-lying and coastal areas of New York City will certainly feel the brunt of this inundation—and many have already begun to experience the impacts. The report suggests that just the current 12 inches of sea level rise may have expanded Hurricane Sandy’s flood area by approximately 25 square miles.
Of all the boroughs, Queens has the most land area at risk of future coastal flooding due to sea level rise, followed by Brooklyn, Staten Island, the Bronx, and Manhattan.
More Storms, More Problems
While continued sea level rise is all but certain, the specific frequency of future storms like hurricanes and nor’easters has proven harder to predict. However, the report’s authors note that it is “more likely than not” that there will be more intense storms, and they will bring extreme winds and intense precipitation.
Coupled with already high sea levels, these storms could cause serious flooding in parts of the City that are already struggling to cope with climate impacts. The report states that “under the high sea level rise estimate for the 2080s, the current 100-year flood (a flood with a 1 percent annual chance of occurrence) is projected to become an approximately once-in-eight year event.”
These changes are reflected most strikingly in the FEMA Flood Insurance Rate Maps. Residents across New York are already seeing the impacts of these maps being updated; if sea level rise continues unabated, by 2100, the area covered by 100-year flood zone will potentially double.
To the Extreme
It’s going to get hotter in New York City—but it’s also going to get wetter and more extreme.
Since 1900, temperatures measured in Central Park have risen 3.4°F, mirroring an increase that’s been seen throughout the entire Northeast, in both rural and urban areas.
By the 2050s, the NPCC suggests that annual temperatures could increase by 4.1 to 5.7°F. By 2080, it could be closer to 8.8°F.
That may not seem like much, especially as we shiver through a snowy February. But keep in mind that these increases will occur in all months of the year. To put things in perspective, the NPCC offers this: “By the 2080s, New York City’s mean temperatures … may bear similarities to those of a city like Norfolk, Virginia, today.”
We can expect to see more days above 90°F, more days above 100°F, and more heat waves (three or more consecutive days above 90°F), too. The NPCC report suggests that by 2080, the number of heat waves could triple—up to six per year.
But the extremes won’t be limited to temperature. Since 1900, annual precipitation has increased a total of 8 inches (about 0.8 inches a decade); the report suggests this increase is likely to continue, but will probably come in the form of short, intense bursts—perfect for flash floods and combined sewage overflows.
The Time for Action is Now
While it is difficult to project individual weather events with any kind of certainty, the NPCC’s report is clear that climate change is a serious and imminent threat to New York City’s people, economy, infrastructure, and natural environment.
And while the City is taking dramatic steps to reduce its greenhouse gas emissions, it must also act now to protect against sea level rise, coastal flooding, and warming temperatures that are now inevitable.
“NPCC’s findings underscore the urgency of not only mitigating our contributions to climate change, but adapting our city to its risks,” said Mayor de Blasio. “The task at hand is daunting— and that is why we’re making an unprecedented commitment, with a sweeping plan to reduce emissions 80 percent by 2050, and a comprehensive, multi-layered resiliency plan that is already making neighborhoods safer.”
The City is also making progress on a number of key projects, including:
- The launch of scoping and preliminary design work on the Lower East Side to implement a $335 million integrated, neighborhood-sensitive flood protection system to mitigate risk and help connect the community with the waterfront.
- The Office of Recovery and Resiliency (ORR), partnering with the New York City Economic Development Corporation (NYCEDC), has launched the first-ever, comprehensive regional resiliency analysis of New York City’s food supply chain network.
- To combat the urban heat island effect, as of the end of 2014, NYC Cool Roofs has coated over six million square feet of building roofs with reflective paint to address the climate change risks associated with urban heat. The City’s recent green buildings plan commits to coating at least one million square feet a year more to continue mitigating the urban heat island effect and provide energy savings in affordable housing, public buildings, and non-profit organizations.
- ORR and NYCEDC have also launched an approximately $100 million shoreline investment program to protect the most vulnerable waterfront communities, including Coney Island Creek and Staten Island’s South Shore, and other low-lying parts of the city that will be evaluated as part of the first phase of work.
Future efforts include upgrading flood protection systems and coastal protection in at-risk areas, preparing NYCHA for heavy flooding, investments in the Staten Island Bluebelt and other storm water infrastructure, and the construction of levees in Midland Beach and on Staten Island’s East Shore.
Many other sustainability plans are outlined in PlaNYC; the mayor’s office will release a progress report for those initiatives in April 2015.
Photo credit: David Bledsoe via Creative Commons