It’s 2050 and the sea level along New Jersey’s oceanfront and bays is 1.5 feet higher than it was at the turn of the century. That may not sound like much, but it’s a major increase considering the daily high tides and occasional hurricanes and nor’easters that flood low-lying areas with storm surges, pounding surf and powerful winds. It’s enough to make the most severe flood that happens in a typical year a permanent state of affairs.
By 2100, the sea level could be 2 feet to 8 feet higher in the Garden State depending on the trajectory of greenhouse gas emissions from human activity and how polar ice sheets respond in the coming decades. Those water levels would permanently inundate many coastal lands and wetlands. Still, government, businesses and residents can take steps to adapt to sea-level rise, increased flooding and growing storm threats.
Rutgers experts are providing sound science and evidence-based recommendations on how to be more resilient to these climate change-related impacts. In the following four essays, Rutgers experts share their insights from science, planning and policy, engineering and sociological perspectives. They have also developed or contributed to many online resilience tools to help New Jersey, counties, towns, businesses and residents adapt to the rising tide.
Illustration by Traci Daberko
Illustration by Traci Daberko
The Future Sea Level in New Jersey:
3 feet, 4 feet, 7 feet higher?
By Robert Kopp, Karl Nordstrom and Johnny Quispe
Since 1900, global average sea level has risen about 8 inches. In New Jersey, sea level has risen even faster – about 1.4 feet over that same period. This is primarily because the land here is sinking, due to both natural forces – the land was pushed up by a giant ice sheet 20,000 years ago and is now relaxing downward – and to groundwater pumping.
Geological records from salt marshes in New Jersey and other sites around the world demonstrate the extraordinary nature of the 20th-century rise in sea level: Both in the global average and locally, it was faster than over any comparable period in at least 3,000 years. And this rise is accelerating due to a warming ocean, melting mountain glaciers and shrinking polar ice sheets.
We are already feeling the effects of sea-level rise. A higher sea means it takes less of a tide or a storm to cause coastal flooding. Sea-level rise has increased the frequency of minor tidal flooding in shore communities about 20-fold since the 1950s. And it exposed about 40,000 New Jerseyans to Superstorm Sandy’s floodwaters who would not have otherwise been affected. With about 600,000 New Jerseyans living within 10 feet of the high tide level in terms of elevation – areas potentially vulnerable to sea-level rise and coastal flooding over the next century – sea-level rise will increasingly affect communities in ways as diverse as land use, infrastructure, property taxes and emergency management.
Over the first half of this century, the Jersey Shore is likely to experience about 1 foot to 2 feet of sea-level rise. A recent study by Climate Central and Zillow, using sea-level rise projections produced at Rutgers, found that between 2010 and 2016, nearly 2,700 homes, worth nearly $3 billion, were built on the Jersey Shore (mostly in Ocean and Cape May counties) in areas expected to flood at least annually by 2050.
Looking beyond 2050, the range of potential sea-level rise becomes increasingly broad. This is because of two big unknowns: the course of future greenhouse gas emissions and the sensitivity of the polar ice sheets – especially the Antarctic ice sheet – to warming.
Since the start of the Industrial Revolution, humans have emitted nearly 1.6 trillion tons of carbon dioxide by burning fossil fuels. These fossil fuel emissions are the primary driver behind a planetary fever of nearly 2 degrees Fahrenheit. Stabilizing the climate – at any level of warming, such as the international goals of 1.5 degrees Celsius (2.7 degrees Fahrenheit) or 2 degrees Celsius (3.6 degrees Fahrenheit) – requires bringing net greenhouse gas emissions to zero. If the world manages to do this in the next half century, then we run a good chance of keeping sea-level rise in New Jersey over the course of this century between 2 feet and 3 feet.
But if emissions continue unchecked on their historic growth trajectory, all bets are off. Unchecked emissions – enough to bring the planetary fever to 7 degrees Fahrenheit or more by the end of the century – might lead to a likely rise of about 2.5 feet to 5 feet in New Jersey. But if more pessimistic models of the Antarctic sensitivity to warming are correct, that range could instead be 4 feet to 8 feet, or more.
Tools such as Rutgers’ NJFloodMapper and Climate Central’s Surging Seas provide an initial sense of what the implications of these different levels of rise would be. With 3.5 feet of sea-level rise, the area subject to annual flooding in New Jersey encompasses about 180,000 people and $80 billion of property. With 7.5 feet of rise, it encompasses nearly 580,000 people and $180 billion of property. But such exposure assessments assume that neither people nor the land they live on respond to sea-level change – assumptions bound to be incorrect.
Under natural conditions, coastal environments respond dynamically to sea-level rise. Low-lying coastal systems and the beaches, dunes and salt marshes within them respond to increased water levels by migrating landward. In developed areas, however, coastal environments are often unable to migrate because buildings, roads and shore protection structures restrict their movement, resulting in erosion in place. In New Jersey, this “coastal squeeze” threatens both settled barrier islands and tidal marshes – the former important places for residence and recreation, the latter providers of key services, including water filtration and storage, storm buffering and bird habitat.
Three broad responses to coastal hazards are available to maintain coastal environments in the face of sea-level rise:
- relocating development away from the shore;
- accommodating natural processes by continuing occupancy and adjusting to the hazard (for example, by building houses on pilings); and
- protecting existing infrastructure in place.
State programs like Blue Acres facilitate relocation and can point to some success stories, but as the Climate Central/Zillow analysis found, houses are being built in exposed areas several times faster than others are being bought out.
Use of hard shore protection structures such as seawalls, bulkheads and groins to protect infrastructure was common in the past. Now, beach nourishment is more common, and New Jersey is one of the national leaders in implementing large-scale nourishment programs. The volume of sediment available for nourishment operations in New Jersey is sufficient for now, but availability in the future is uncertain. Replenishing the beach, also known as nourishment, pushes plant and animal habitats toward the sea, where they would normally seek to move toward the land.
It is critical that the state and coastal communities develop resilience plans that are robust to the range of possible futures the state might face. We need approaches that are science-based and robust to the range of possible futures. Doing so requires coordination; it cannot happen one municipality at a time. A regional approach requires increased communication, provides opportunities for collaboration and facilitates the pooling of resources to complete large-scale projects that are infeasible for individual entities.
Rutgers is playing a key role in helping bring such efforts to fruition. And we cannot treat planning for future sea-level rise as independent of efforts to decarbonize the state, national and global economy. The magnitude of the sea-level rise to which we must adapt depends integrally on the magnitude of the fever we allow the Earth to run.
Illustration by Traci Daberko
Illustration by Traci Daberko
How to Save New Jersey from the Rising Tide? Translating Science to Action
By Marjorie Kaplan, Lisa Auermuller and Jeanne Herb
As we approach the seventh anniversary of Superstorm Sandy, we are asked – as we have been every autumn since 2012 - “Are we better prepared for the next Sandy?” Our answer: In some places and with respect to some structures and systems, we probably are, but in many others we are not or we won’t know until the next big storm.
We have been working together on issues related to preparedness in the face of sea-level rise in New Jersey since before Superstorm Sandy, but that seminal event provided an opportunity to further our applied research and advance a dialogue on an issue that, even post-Sandy, some policymakers and elected officials still shy away from.
Rutgers, with a mission of service to New Jersey, is in a unique position to provide continuity to address the factual realities of climate change independent of politics. As “pracademics” – or academicians who also are practitioners – we translate science to inform policy and action for local communities as well as specific sectors of society that are affected by sea-level rise. We are privileged to be at Rutgers, where we collaborate with colleagues from across the university in the natural and social sciences, engineering, health, planning, policy, law, communications and humanities, so we can take transdisciplinary approaches to our work. We also have access to the communities we serve through field stations such as the Jacques Cousteau National Estuarine Research Reserve.
One example of where we bridge between the university and community is work we conduct for the New Jersey Climate Change Alliance, a diverse nonpartisan network that advances evidence-informed climate change strategies at the state and local levels in New Jersey. Since 2011, the Rutgers Climate Institute and the Bloustein School of Planning and Public Policy have facilitated the Alliance, which formed a year before Sandy, a storm that reinforced the value of its mission. On behalf of the Alliance, we conduct research and analyses, develop user-friendly decision-support tools and educational and outreach materials and conduct events so New Jerseyans can better understand and address climate change.
At the Alliance’s request, we convened a Science and Technical Advisory Panel of experts to identify and evaluate the most current science on sea-level rise projections, coastal storms and resulting flood risk; to consider the implications for the practices and policies of New Jersey stakeholders; and to provide practical options for them to incorporate science into risk-based decision processes. To complement this process, we brought together a panel of resilience practitioners who provided feedback to the science panel on barriers and opportunities for integrating the science panel’s conclusions into practice.
We conducted additional research to better understand how municipal decision-makers and practitioners use coastal hazard data, and to understand pertinent local, state and federal regulatory frameworks and the degree to which coastal climate change impacts are addressed in New Jersey.
We have learned that municipal decision-makers and professionals agree there is a greater recognition regarding sea-level rise impacts in New Jersey coastal areas as a result of increased awareness following Superstorm Sandy and a greater support for protective regulatory measures. But they also desire a more holistic approach to resilience guided by a statewide vision for planning and implementation. They also have concerns that the post-Sandy emphasis on elevating structures may provide a false sense of security regarding long-term resiliency. They fear residents will avoid evacuating during storms because they fail to consider the roadways, infrastructure and critical facilities that remain exposed and non-resilient. They note sea-level rise planning numbers need to be consistent within and between state agencies and communicated to local decision-makers. They suggest that integrating sea-level rise projections with local knowledge about historic flooding can inform decision-making, and that using historic flood data as a reference point can help to communicate current and future impacts.
Preparedness for sea-level rise and coastal flooding involves collaboration among many actors, including municipal, state and federal decision-makers; public and private sector leaders; natural and social scientists; and residents and businesses in coastal communities. At Rutgers, we advance our research while we apply our results. Two examples:
- “Getting to Resilience” assessment process conducted in more than 60 New Jersey municipalities and
- “Two Rivers, One Future,” a 15-municipality regional resilience planning project in Monmouth County in partnership with the state of New Jersey.
We recognize planning decisions have implications far into the future. Such decisions must consider many factors and are not to be taken lightly. It is our hope that by providing evidence-based information, we can help New Jerseyans adapt to sea-level rise. And we hope that before the next major storm hits, we will indeed get to an October where we can say: Yes, we are indeed better prepared than we were in 2012.
Illustration by Traci Daberko
Illustration by Traci Daberko
Mobile and Green Infrastructure
Adaptation to Sea-Level Rise
By Qizhong (George) Guo
In New Jersey’s effort to adapt to rising sea levels, we are facing infrastructure challenges on two fronts – structural deterioration and environmental change. This is the time for us to tackle both fronts together by replacing or retrofitting the aged infrastructure into a resilient one, preferably through mobile and green means.
What are the consequences of sea-level rise?
First, nuisance flooding during high tides even when there is no rainfall as has already happened in low-lying coastal areas in New Jersey and elsewhere. Second, saltwater intrusion into aquifers that threatens the potable water supply. Third, more frequent and severe flooding during rainfall events as the urban storm drainage systems and/or rivers are backed up by the higher sea level. And fourth, higher levels of water, flooding and erosion during hurricanes and nor’easters as the storm surge is superimposed on a higher sea level, among other consequences.
What are the straight-forward ways to deal with the sea-level rise?
Elevation, seawall, pumping and relocation/retreat. For example, the city of Miami Beach, Florida, is spending $500 million to raise roads and seawalls by 2 feet as well as to install pump stations for about $2 million per block. Also, the few dozen residents of Isle de Jean Charles in Louisiana, a rapidly disappearing island in the Gulf of Mexico, are to be relocated through a $48 million federal grant.
Why do I prefer mobile infrastructure?
First, the sea-level rise projection is uncertain. For the New Jersey shore, it was projected to rise by end of this century from 2.5 feet to about 6 feet. Second, infrastructure that is mobile and vertically and/or horizontally extendable would be much easier to adapt to this large range of projection. Mobile infrastructure can be adjusted as the sea level rises or when a hurricane is approaching.
Why do I prefer green infrastructure?
First, green infrastructure is natural and/or nature-based, constructed from local soils, plants and/or animals, such as oysters, and thus is more adaptive to environmental changes. Second, green infrastructure has many ecological and social co-benefits besides the economical benefits.
What mobile and green measures have already been implemented?
First, beach replenishment and sand dune restoration is a mobile and green solution already in action at the Jersey Shore. A study for Delaware in 2001 found that one dollar spent on beach replenishment would prevent four dollars in loss from retreat. However, the sediment budget should be further assessed for sustainability of this practice as well as the costs and benefits far into the future. Second, clean sediment accumulated in navigation channels has been dredged to fill up drowning wetlands. Sediment inputs from uplands/watersheds are expected to change as the climate changes through rainfall and land cover changes, and an assessment of these sediment changes will help experts decide how much sediment can be dredged in the future. Third, stormwater green infrastructure such as rain gardens and porous pavements are being actively implemented to mitigate local flooding by reducing and/or slowing rainfall-generated runoff. For example, we have constructed six rain gardens and two porous parking lots in Linden, NJ. The co-benefits of green infrastructure as well as the methods and costs of maintenance should be further understood and quantified.
What additional mobile and green measures have been proposed?
Since Superstorm Sandy, we have researched coastal flood mitigation measures and proposed a framework for developing comprehensive strategies. Those strategies include consideration of threats from different sources of water, different levels of threats and vulnerability, different types and functions of measures and different aspects of assessment. We have additionally proposed:
- Harvesting energy from rainwater, wind, waves and currents to pump out the flood water;
- Erecting vertically extendable floodwalls that can be flipped up when storm surges approach while maintaining the view and access most of the time or adding height as the sea level rises;
- Constructing causeways over tidal rivers and salt marshes with operable surge barriers to let normal tidal flows go through to maintain the ecosystem while fending off storm surges;
- Utilizing coastal and ocean monitoring and analysis systems as well as smart technologies to guide the mobilization of infrastructure and people.
For New Jersey to adapt to rising sea levels, we must be open to innovative ideas and social, technological and environmental changes. The dual challenges of infrastructure deterioration and climate change present us with a great opportunity to collaborate and put our innovative thinking to use.
Illustration by Tracie Daberko
Illustration by Tracie Daberko
Out of Harm’s Way?
By Karen O’Neill
New Jerseyans have long adapted to change along coastal rivers and ocean shorelines, and they continue to adapt today. The question now is whether we expect people who live and work near the shore to pay most of the costs of adapting, including the costs of moving away when that seems the best choice.
People in our state have accepted hazards as the price of living near water. The indigenous Lenape peoples, who lived in New Jersey well into the colonial period, took advantage of near-shore fisheries during the summer and moved back inland as the seasons changed. Understanding the benefits of that seasonal pattern lessened over time. Early European settlers appreciated coastal threats, but they soon built ports and settlements. Since then, coastal settlements have been periodically devastated by storm surges and winds. New Jersey is now experiencing a rise in relative sea levels more quickly than nearly any other place on earth, speeding up this pattern of devastation.
We have typically built barriers or accommodated rising waters by raising our structures and moved only when these other options failed. In places where property values are rising, efforts to stay in place may seem worthwhile. Federal flood insurance and disaster aid policies encourage people to rebuild in place. Yet ecological damages from fixing the shoreline in place are threatening our state’s overall quality of life. And because many of our barrier protections are aging, we have the opportunity to reevaluate whether the social costs of staying in place are also becoming too high.
Facing the effects of climate change, people in some places in our state are already starting to move out of harm’s way. Unfortunately, because retreat from the coast is often seen as a defeat – and almost un-American – there has not been a broad and public discussion of the options for moving away from these hazards. Residents and business owners have ended up moving under distressing conditions, after suffering repeated losses from flooding or sudden devastation from storm surges. A patchwork of federal, state and charitable policies and aid programs provide for only some of their needs after being forced out.
The people most eager for buyouts are those facing declining property values who cannot afford to build barriers or to raise their houses. Renters may find it difficult to find aid to move out and are often under-insured for disaster damages. Even owners who have the means to rebuild to higher standards may be witnessing environmental changes that make them interested in moving. The New Jersey state government Blue Acres program offers a nationally recognized approach to coordinating buyouts for people who are already willing to move, often working to match or leverage funding from other state and federal programs. Expanding these buyout programs could provide immediate relief to people who are ready to move.
Allowing natural coastal dynamics to reshape at least some parts of the coastline can save money and reduce human suffering. For sites in Newark and other cities, it may seem obvious that we must commit to building ever-higher barriers to protect our current uses. Yet even in cities, we could choose to move some structures from the shoreline. For example, it may not make sense to build seawalls to protect abandoned industrial sites. Once any potential contaminants have been moved or secured at these sites, water could be allowed to flood these shorelines during storms, while new barriers are built farther inland. This could reduce the costs of protections and direct that money and human effort toward investments in lands that are higher and drier.
Along less developed shorelines outside cities, we can remove outmoded structures like abandoned jetties and re-establish important ecological functions that protect us all. These changes can produce benefits for the people of New Jersey more broadly by allowing the shoreline to absorb the force of storm surges, hosting important animal and plant species and increasing the beauty of the shore.
It is time to apply our creativity toward remaking shorelines that are beautiful and useful and toward helping people make these transitions financially and socially. This will require rethinking our state government’s role in aiding municipalities that may fear the loss of local tax revenues, helping them to recognize that the costs of maintaining those lots may actually exceed the property revenues they produce. We will also have to find ways of supporting coastal cultures and ways of life as the seas rise and storms become more threatening. Our state’s natural resources, cultural diversity and wealth can sustain us through this transition and provide models for adaptation elsewhere.
Rising Tide Resources
Rutgers University experts have developed or contributed to many websites and online tools that can help New Jersey, counties, towns, businesses and people become more resilient in the face of climate change, rising tides and increased flooding and storm damage. Here is a partial list:
NJFloodMapper is an interactive mapping tool to help communities and others decide how to address flooding hazards and sea-level rise.
New Jersey Resilient Coastal Communities Initiative has a Getting to Resilience online self-assessment tool to help communities reduce vulnerability and increase preparedness through planning, mitigation and adaptation. Rutgers is a key participant in the initiative, which has a website that offers sea-level rise and flooding information, web links, FAQ, tutorials, case studies, mapping tools, municipal maps, risk communication information and resilience checklists.
NJADAPT is a collaborative project of Rutgers and other academic institutions, local practitioners and state and federal agencies. Its online tool focuses on how a changing climate is affecting and will continue to affect various populations, places and assets in New Jersey.
NJ FRAMES project is funded by the National Oceanic and Atmospheric Administration and led by the NJ Department of Environmental Protection. The project involves 15 municipalities in coastal Monmouth County. With help from Rutgers and other experts, the project seeks to understand and begin addressing future vulnerability to flooding. It will lead to a regional resilience and adaptation action plan that will identify ways communities can reduce risks and impacts together.
Rutgers Climate Institute has many climate change-related resources, including data and climate education information.
New Jersey Climate Change Alliance, facilitated by Rutgers University, also has many resources, including reports and videos.