NPCC

New York City Panel on Climate Change

NPCC4: New York City climate risk information 2022 – observations and projections

Introduction

Climate Science & Projections Work Group Co-Chairs:
Christian Braneon and Luis Ortiz

This New York City Panel on Climate Change (NPCC4) special report offers current climate projections for use by New York City (NYC) for decision-making about climate change impacts. It draws from and updates the findings reported in the 2nd and 3rd NPCCs and the New York State Climate Impact Assessment. Its primary focus areas are (1) sea level rise and storm surge; (2) inland and coastal flooding; (3) average and extreme temperatures; and (4) extreme precipitation and drought.

This report provides detailed discussions on the climate risks that New York City is facing now, and how these risks will likely impact the city in the future.

The report notes that sea levels will continue to rise globally, and projected sea level rise in New York City is expected to lead to more dangerous storm surges and frequent high-tide flooding. While there have been efforts to protect neighborhoods and critical infrastructure in New York City in case of future floods, many areas remain vulnerable to coastal flooding.

Projections for sea level rise in New York City for 2030-2150

Temperatures are also going to continue to fluctuate in the current century. The number of days below freezing in New York City is projected to decrease while the number of hotter days is expected to increase. New York City will also experience a greater frequency of extreme weather events, as the number of heat waves is expected to increase, as is the frequency of heavy rainfalls and periods of drought.

Photo Credit: Jamaica Bay Living Shoreline: City of New York Department of Environmental Protection

Read the Chapter

Authors

Christian Braneon, Ph.D. CUNY Institute for Demographic Research, City University of New York, New York, NY., NASA Goddard Institute for Space Studies, New York, NY., Columbia Climate School, Columbia University, New York, NY.

Luis Ortiz, Ph.D. Department of Atmospheric, Oceanic, and Earth Sciences, George Mason University, Fairfax Country, VA.

Dan Bader, MA Center for Climate Systems Research, Columbia University, New York, NY., NASA Goddard Institute for Space Studies, New York, NY.

Naresh Devineni, Ph.D. Department of Civil Engineering and CUNY CREST Institute, The City College of New York, New York, NY.

Philip Orton, Ph.D. Stevens Institute of Technology, Hoboken, NJ.

Bernice Rosenzweig, Ph.D. Department of Environmental Science, Sarah Lawrence College, Bronxville, NY.

Timon McPhearson, Ph.D. Urban Systems Lab, The New School, New York, NY., Cary Institute of Ecosystem Studies, Millbrook, NY., Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden.

Lauren Smalls-Mantey, Ph.D New York City Department of Health and Mental Hygiene, New York, NY.

Vivien Gornitz, Ph.D. NASA Goddard Institute for Space Studies, New York, NY.

Talea Mayo, Ph.D. Department of Mathematics, Emory University, Atlanta, GA.

Sanketa Kadam, MSc. Columbia Climate School, Columbia University, New York, NY.

Hadia Sheerazi, dual Msc. RMI (founded as the Rocky Mountain Institute), New York, NY.

Equisha Glenn, Ph.D. Metropolitan Transportation Authority, New York, NY.

Liv Yoon, Ph.D. The University of British Columbia, Vancouver, BC Canada.

Amel Derras-Chouk, Ph.D. Department of Earth and Atmospheric Sciences, The City College of New York, New York, NY.

Joel Towers, MArch. Parsons School of Design, The New School, New York, NY., The Tishman Environment and Design Center, The New School, New York, NY

Robin Leichenko, Ph.D. Department of Geography, School of Arts and Sciences, Rutgers Climate Institute, Rutgers University, New Brunswick, NJ.

Deborah Balk, Ph.D. Marxe School of Public and International Affairs, Baruch College at the City University of New York (CUNY), CUNY Institute for Demographic Research (CIDR), City University of New York, New York, NY.

Peter Marcotullio, Ph.D. Department of Geography and Environmental Science, Hunter College, CUNY, New York, NY.

Radley Horton, Ph.D. Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY., Columbia Climate School, Columbia University, New York, NY.

Summary

Related Links

  • Key Message 1

    Sea level is projected to rise for centuries and remain elevated for thousands of years.

    Glaciers and ice sheets combined are now the dominant contributors to global mean sea level rise (GMSLR). In the future, the cryosphere contributions will dominate, especially in higher GMSLR scenarios. Changes in ocean circulation, such as the Atlantic Meridional Overturning Circulation may also play an increasing role in the future. Coastal locations in the NYC metropolitan region continue to experience higher rates of relative sea level rise as compared to the global mean, a trend that is generally expected to continue into the future. Projected sea level rise for NYC will exacerbate the destructive hazards posed by storm surges and cause more frequent high-tide flooding. Although many improvements have been made to protect neighborhoods and secure critical infrastructure in future floods, many neighborhoods remain vulnerable to coastal flooding. More research is needed on both the baseline storm surge hazard as well as its potential future changes.

  • Key Message 2

    Surface and air temperature varies throughout NYC as a function of time of day, season, and the underlying characteristics of the built environment. The number of days with minimum temperatures below freezing has been steadily declining since 1900.

    The total number of hot days in the city is expected to increase as this century progresses. The frequency and duration of heat waves are also expected to increase. In general, the projected changes in precipitation are small relative to year-to-year variability. Average annual precipitation in NYC is projected to increase by approximately 2 to 7 percent by the 2030s, 4 to 11 percent by the 2050s and 7 to 17 percent by the 2080s (all relative to a 1981-2010 baseline period). Although the increase in total annual precipitation is projected to be relatively small, global climate models project somewhat larger increases in the frequency of extreme precipitation events.

  • Key Message 3

    The largest recorded drought in the New York metropolitan region occurred during the 1960s. This event serves as a critical benchmark to evaluate potential impacts of extreme drought and vulnerability to low water availability in the region, with current water management practices designed around that event.

    Since the 1960s drought of the record, several smaller droughts have had measurable impacts. Consideration of water management under drought currently relies on estimates of imbalances between annual supply and evaporative losses, but droughts are manifestation of the non-linear interaction between supply and demand as the climate risks faced by water users vary over time and by sector of use. There is a need for more comprehensive assessment of drought vulnerability that accounts for projected changes in cross-sectoral demand as well as projected climate impacts.