Shifting landscapes of coastal flood risk: environmental (in)justice of urban change, sea level rise, and differential vulnerability in New York City

AbstractCoastal flood risk assessments require accurate land elevation data. Those to date existed only for limited parts of the world, which has resulted in high uncertainty in projections of land area at risk of sea-level rise (SLR). Here we have applied the first global elevation model derived from satellite LiDAR data. We find that of the worldwide land area less than 2 m above mean sea level, that is most vulnerable to SLR, 649,000 km2 or 62% is in the tropics. Even assuming a low-end relative SLR of 1 m by 2100 and a stable lowland population number and distribution, the 2020 population of 267 million on such land would increase to at least 410 million of which 72% in the tropics and 59% in tropical Asia alone. We conclude that the burden of current coastal flood risk and future SLR falls disproportionally on tropical regions, especially in Asia.

Download Full-text

Impact of climate change on New York City’s coastal flood hazard: Increasing flood heights from the preindustrial to 2300 CE

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1703568114 ◽

2017 ◽

Vol 114 (45) ◽

pp. 11861-11866 ◽

Cited By ~ 73

Author(s):

Andra J. Garner ◽

Michael E. Mann ◽

Kerry A. Emanuel ◽

Robert E. Kopp ◽

Ning Lin ◽

...

Keyword(s):

New York ◽

New York City ◽

Sea Level Rise ◽

Sea Level ◽

Tropical Cyclones ◽

York City ◽

Flood Hazard ◽

Storm Surges ◽

Cmip5 Models ◽

Tidal Level

The flood hazard in New York City depends on both storm surges and rising sea levels. We combine modeled storm surges with probabilistic sea-level rise projections to assess future coastal inundation in New York City from the preindustrial era through 2300 CE. The storm surges are derived from large sets of synthetic tropical cyclones, downscaled from RCP8.5 simulations from three CMIP5 models. The sea-level rise projections account for potential partial collapse of the Antarctic ice sheet in assessing future coastal inundation. CMIP5 models indicate that there will be minimal change in storm-surge heights from 2010 to 2100 or 2300, because the predicted strengthening of the strongest storms will be compensated by storm tracks moving offshore at the latitude of New York City. However, projected sea-level rise causes overall flood heights associated with tropical cyclones in New York City in coming centuries to increase greatly compared with preindustrial or modern flood heights. For the various sea-level rise scenarios we consider, the 1-in-500-y flood event increases from 3.4 m above mean tidal level during 1970–2005 to 4.0–5.1 m above mean tidal level by 2080–2100 and ranges from 5.0–15.4 m above mean tidal level by 2280–2300. Further, we find that the return period of a 2.25-m flood has decreased from ∼500 y before 1800 to ∼25 y during 1970–2005 and further decreases to ∼5 y by 2030–2045 in 95% of our simulations. The 2.25-m flood height is permanently exceeded by 2280–2300 for scenarios that include Antarctica’s potential partial collapse.

Download Full-text

Sediment starvation destroys New York City marshes’ resistance to sea level rise

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1715392115 ◽

2018 ◽

Vol 115 (41) ◽

pp. 10281-10286 ◽

Cited By ~ 17

Author(s):

Dorothy M. Peteet ◽

Jonathan Nichols ◽

Timothy Kenna ◽

Clara Chang ◽

James Browne ◽

...

Keyword(s):

New York ◽

New York City ◽

Sea Level Rise ◽

Sea Level ◽

York City ◽

Organic Sediment ◽

Jamaica Bay ◽

Structural Weakness ◽

Global Sea Level ◽

Matter Flux

New York City (NYC) is representative of many vulnerable coastal urban populations, infrastructures, and economies threatened by global sea level rise. The steady loss of marshes in NYC’s Jamaica Bay is typical of many urban estuaries worldwide. Essential to the restoration and preservation of these key wetlands is an understanding of their sedimentation. Here we present a reconstruction of the history of mineral and organic sediment fluxes in Jamaica Bay marshes over three centuries, using a combination of density measurements and a detailed accretion model. Accretion rate is calculated using historical land use and pollution markers, through a wide variety of sediment core analyses including geochemical, isotopic, and paleobotanical analyses. We find that, since 1800 CE, urban development dramatically reduced the input of marsh-stabilizing mineral sediment. However, as mineral flux decreased, organic matter flux increased. While this organic accumulation increase allowed vertical accumulation to outpace sea level, reduced mineral content causes structural weakness and edge failure. Marsh integrity now requires mineral sediment addition to both marshes and subsurface channels and borrow pits, a solution applicable to drowning estuaries worldwide. Integration of marsh mineral/organic accretion history with modeling provides parameters for marsh preservation at specific locales with sea level rise.

Download Full-text

Impacts of sea level rise in the New York City metropolitan area

Global and Planetary Change ◽

10.1016/s0921-8181(01)00150-3 ◽

2001 ◽

Vol 32 (1) ◽

pp. 61-88 ◽

Cited By ~ 118

Author(s):

Vivien Gornitz ◽

Stephen Couch ◽

Ellen K Hartig

Keyword(s):

New York ◽

New York City ◽

Sea Level Rise ◽

Sea Level ◽

Metropolitan Area ◽

York City

Download Full-text

New York City Storm Surges: Climatology and an Analysis of the Wind and Cyclone Evolution

Journal of Applied Meteorology and Climatology ◽

10.1175/2009jamc2189.1 ◽

2010 ◽

Vol 49 (1) ◽

pp. 85-100 ◽

Cited By ~ 33

Author(s):

Brian A. Colle ◽

Katherine Rojowsky ◽

Frank Buonaito

Keyword(s):

New York ◽

New York City ◽

Sea Level ◽

York City ◽

Storm Surges ◽

High Water ◽

Storm Tide ◽

Coastal Flood ◽

Cyclone Tracking ◽

Flooding Events

Abstract A climatological description (“climatology”) of storm surges and actual flooding (storm tide) events from 1959 to 2007 is presented for the New York City (NYC) harbor. The prevailing meteorological conditions associated with these surges are also highlighted. Two surge thresholds of 0.6–1.0 m and >1.0 m were used at the Battery, New York (south side of Manhattan in NYC), to identify minor and moderate events, respectively. The minor-surge threshold combined with a tide at or above mean high water (MHW) favors a coastal flood advisory for NYC, and the moderate surge above MHW leads to a coastal flood warning. The number of minor surges has decreased gradually during the last several decades at NYC while the number of minor (storm tide) flooding events has increased slightly given the gradual rise in sea level. There were no moderate flooding events at the Battery from 1997 to 2007, which is the quietest period during the last 50 yr. However, if sea level rises 12–50 cm during the next century, the number of moderate flooding events is likely to increase exponentially. Using cyclone tracking and compositing of the NCEP global reanalysis (before 1979) and regional reanalysis (after 1978) data, the mean synoptic evolution was obtained for the NYC surge events. There are a variety of storm tracks associated with minor surges, whereas moderate surges favor a cyclone tracking northward along the East Coast. The average surface winds at NYC veer from northwesterly at 48 h before the time of maximum surge to a persistent period of east-northeasterlies beginning about 24 h before the surge. There is a relatively large variance in wind directions and speeds around the time of maximum surge, thus suggesting the importance of other factors (fetch, storm duration and track, etc.).

Download Full-text