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A.R. Siders - University of Delaware. Newark, DE, US

A.R. Siders

Director, Climate Change Science & Policy Hub | Core Faculty, Disaster Research Center | Associate Professor, Biden School of Public Policy and Administration & Department of Geography & Spatial Sciences | University of Delaware


Prof. Siders' research focuses on climate change adaptation policies with an emphasis on relocation and fairness in adaptation.







Everything you wanted to know about Managed Retreat (but were afraid to ask) with Dr. AR Siders Plan for the Planet: A.R. Siders Managed retreat: A critical tool to combat climate change Managed retreat—a powerful tool for future climate change adaptation




A.R. Siders is a director of the Gerard J. Mangone Climate Change Science and Policy Hub. She is an associate professor at the University of Delaware in the Disaster Research Center, the Biden School of Public Policy and Administration, and the department of Geography and Spatial Sciences in the College of Earth, Ocean, and Environment. She holds a JD from Harvard Law School and a PhD from the Emmett Interdisciplinary Program in Environment and Resources at Stanford University.

Dr. Siders' research focuses on climate change adaptation decision-making and evaluation: how and why communities decide when, where, and how to adapt to the effects of climate change and how these decisions affect risk reduction and justice. She has expertise on climate adaptation policy at local, state, and federal levels in the United States and international policy. Her current projects focus on adaptive capacity, managed retreat, and adaptation fairness. She co-edited a book and special issue on environmental justice and climate relocation, and she recently served as a contributing author to the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report and to the Fifth US National Climate Assessment (NCA5) and as a synthesis lead for the Global Adaptation Mapping Initiative.

Industry Expertise (5)


Government Administration

Environmental Services

Computer Gaming

Public Policy

Areas of Expertise (9)

Flood Exposure & Resilience

Climate & Disaster Study

Managed Retreat

Environmental Justice

Climate-related Hazards

Climate Change Adaptation Policies

Climate Change Adaptation

Climate Change

Environmental Video Games

Answers (1)

What is managed retreat?

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Managed retreat is a category of adaptation options where communities either don't build near to hazards or where people move away from the hazards. We tend to talk about managed retreat from the coasts, because sea level rise is one of the most visible and concrete consequences of global climate change, but managed retreat options are applicable in any flood-prone area.Siders recently collaborated with the University of Miami's Katharine J. Mach to provide a prospective roadmap for reconceptualizing the future using managed retreat. Siders and Mach argue that long-term adaptation will involve retreat. Even traditionally accepted visions of the future, like building flood walls and elevating threatened structures, will involve small-scale retreat to make space for levees and drainage. Larger-scale retreat may be needed for more ambitious transformations, such as building floating neighborhoods or cities, turning roads into canals in an effort to live with the water, or building more dense, more compact cities on higher ground.

Media Appearances (20)

As climate change soaks New England, flash flooding is costing cities

The Boston Globe  online


A.R. Siders, professor and researcher with UD’s Disaster Research Center, lent her expertise on flash flooding costs in New England.

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Delaware urged to step up climate action amid national calls for more adaptation

Delaware Public Media  radio


According to AR Siders some Delaware officials understand that the massive effects of a changing climate will require commensurate responses such as road relocations or revised building codes but that no such measures have yet been agreed, let alone implemented.

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University of Delaware researcher one of 500 contributors to Fifth National Climate Assessment

The White House, United Nations  online


Leaders and practitioners highlighted the findings and raised awareness of climate impacts and solutions at a release event on Nov. 14. White House and climate leaders from across the country elevated the key themes of NCA5 and further highlight the Biden Administration’s whole-of-government approach to mitigating and adapting to climate change.

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3 cities face a climate dilemma: to build or not to build homes in risky places

NPR  online


On a state level, New Jersey may offer a blueprint for how to get people out of harm's way while continuing to grow and prosper economically, said A.R. Siders, core faculty with UD's Disaster Research Center.

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Wealthy buyers are flocking to Florida to rebuild mansions where modest homes were destroyed by hurricanes

Business Insider (India)  online


Wealthy buyers are flocking to Florida to rebuild mansions where modest homes were destroyed by hurricanes. "This looks like a good short-term solution because it doesn't involve the government spending a lot of money," A.R. Siders, a professor at the University of Delaware's Disaster Research Center, told Bloomberg. "In the long-term, it opens up a can of worms."

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Ravaged Florida Town Becomes a Magnet for Risk-Taking Homebuyers

Bloomberg  online


Fort Myers Beach, destroyed by Hurricane Ian’s winds and flooding, is being remade by those who can afford to build stronger structures — and face future storms

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How Biden’s newest climate initiative affects campus

The Review (UD's Independent Student Newspaper)  online


“I think there’s a trickle effect,” Siders said when talking about implementing climate mitigation policy. “As people … [we] see what becomes normal somewhere else, then that just that influences what people think is the norm is the standard what’s possible.” Siders put forth that climate mitigation needs to be more involved in higher education. She also emphasized the need for climate knowledge in fields such as engineering.

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Where Climate Change Education Stands in Delaware

Delaware Public Media  radio


A number of states are changing their standards and curricula to address climate change, but advocates say coverage of the issue remains largely limited in education. To help shine a spotlight on climate change education, the Climate Change Science and Policy Hub at the University of Delaware is holding a two-day workshop on strategies to build diverse, inclusive, and supportive climate education in the Mid-Atlantic region. Delaware Public Media’s Kyle McKinnon talks this week with UD’s Climate Change Science and Policy Hub director A.R. Siders about the workshop and how to effectively teach climate change.

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No water, roads or emergency services: How climate change left a rural neighborhood nearly uninhabitable

Texas Tribune  online


Buyout programs are supposed to have protections that prevent local governments from removing critical services, said A.R. Siders, an assistant professor at the University of Delaware and member of the university’s Disaster Research Center. But in reality, as fewer people live in an area, it makes less sense to spend tax dollars there. And government officials are hesitant to trample on people’s property rights to force them to leave, she said. “The idea of individual property rights treats it as though [homes] are isolated, but they’re not,” said Siders, one of the leading researchers on managed retreat. “...Those homes are very dependent on government systems: the roads, the water services, the septic systems, emergency services.”

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‘We are not prepared’: Disasters spread as climate change strikes

Politico  online


In addition to coordinating disaster response, FEMA also runs the U.S. federal flood insurance program. And it simply is not ready to juggle the myriad perils that climate change is spitting out, said A.R. Siders, an assistant professor at the University of Delaware who focuses on disasters. “I think as a whole in the United States we are not prepared to deal with the effects of a changing climate,” she said. “We are doing too much in the reaction mode rather than the preparation mode.”

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Climate change is causing people to move. They usually stay local, study finds



It makes sense that people are moving only short distances, says A.R. Siders, a faculty member at the Disaster Research Center at the University of Delaware. Most Americans who move for any reason do so within the same county, Siders says. "It's useful to see that, even when people are moving because of a flood-related program, they are staying close."

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How to Convince Homeowners to Relocate Because of Climate Change

Route Fifty  online


“Sometimes it’s less about the data, and it’s more about how we communicate the data,” Siders said. For instance, the 100-year flood principle, which is often used to determine if a household requires flood insurance, asserts that a given area has a 1% chance of flooding annually. “The other way to think about that is … you have a 1 in 4 chance of your home flooding during the course of a mortgage,” [Siders] said. To help translate complex ideas like flood risk to a community, Siders advised using data to tell a story. That means leveraging tools that make data relevant to the audience. “If you just show a flat map on a table or a chart of the data … it’s not effective at convincing them that there’s actual risk.”

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Cities vs. Rising Seas

The New York Times  online


Around the world, tens of millions could lose their homes in the coming decades. Planning is the key to protecting them.

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What is Managed Retreat? A Controversial Climate Adaptation Scientists Say Is Inevitable

NBC6 South Florida  tv


We know that chaotic retreat happens after big disasters like Hurricane Irma, but managed retreat is trying to get out ahead of the problem. “The general principles behind a managed retreat, what would make it different from chaotic retreat, are really having agency over the choice, so making it feel like people who are retreating making it feel like this is a choice for them," Siders said.

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One City’s Escape Plan From Rising Seas

Wired  online


We urgently need to shift to strategic efforts that include sociocultural as well as physical factors and involve the whole country. As Professor A. R. Siders of the University of Delaware, a leading academic in the emerging field of strategic relocation, says, “A substantial amount of innovation and work—in both research and practice—will need to be done to make strategic [relocation] an efficient and equitable adaptation option at scale.”

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Meet the multimillion-dollar building deliberately built to drown

The Washington Post  online


A.R. Siders, an assistant professor in the Biden School of Public Policy and Administration and a member of the University of Delaware’s Disaster Research Center who studies adaptation to climate change, said policies like these could make it easier for people to move away from threatened areas.

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Climate change makes living at the coast riskier. But more people keep coming.

USA Today  online


People don't like to talk about towns losing population, but that's unrealistic, said A.R. Siders, an assistant professor in the disaster research center at the University of Delaware. "We're not very good in the United States about dealing with shrinking towns, whether they're shrinking because of sea level rise and climate change issues, or they're shrinking because an economy has collapsed."

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"Managed Retreat": A Solution to Communities Impacted by Climate Change

The Takeaway  online


We talk with A.R. Siders, an assistant professor at the University of Delaware and climate change adaptation expert on what managed retreat is and how it has been implemented across the US.

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We Need to Manage a Careful Retreat From Climate Change, Scientists Urge

Science Alert  online


"Climate change is affecting people all over the world, and everyone is trying to figure out what to do about it," says disaster researcher A.R. Siders from the University of Delaware.

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Delaware urged to step up climate action amid national calls for more adaptation

Delaware Public Media  radio


According to AR Siders, a University of Delaware professor who focuses on adaptation to climate change, some Delaware officials understand that the massive effects of a changing climate will require commensurate responses such as road relocations or revised building codes but that no such measures have yet been agreed, let alone implemented.

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Articles (5)

Promoting Spatial Coordination in Flood Buyouts in the United States: Four Strategies and Four Challenges from the Economics of Land Preservation Literature

Natural Hazards Review

2023 Managed retreat in the form of voluntary flood-buyout programs provides homeowners with an alternative to repairing and rebuilding residences that have sustained severe flood damage. Buyout programs are most economically efficient when groups of neighboring properties are acquired because they can then create unfragmented flood control areas and reduce the cost of providing local services. However, buyout programs in the United States often fail to acquire such efficient, unfragmented spaces, for various reasons, including long administrative timelines, the way in which buyout offers are made, desires for community cohesion, and attachments to place. Buyout programs have relied primarily on posted price mechanisms involving offers that are accepted or rejected by homeowners with little or no negotiation. In this paper, we describe four alternative strategies that have been used successfully in land-preservation agricultural–environmental contexts to increase acceptance rates and decrease fragmentation: agglomeration bonuses, reverse auctions, target constraints, and hybrid approaches. We discuss challenges that may arise during their implementation in the buyout context—transaction costs, equity and distributional impacts, unintended consequences, and social pressure—and recommend further research into the efficiency and equity of applying these strategies to residential buyout programs with the explicit goal of promoting spatial coordination.

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Critical facility accessibility and road criticality assessment considering flood-induced partial failure

Sustainable and Resilient Infrastructure

2023 This paper examines communities’ accessibility to critical facilities such as hospitals, emergency medical services, and emergency shelters when facing flooding. We use travel speed reduction to account for flood-induced partial road failure. A modified betweenness centrality metric is also introduced to calculate the criticality of roads for connecting communities to critical facilities. The proposed model and metric are applied to the Delaware road network under 100-year floods. This model highlights the severe critical facility access loss risk due to flood isolation of facilities. The mapped post-flooding accessibility suggests a significant travel time increase to critical facilities and reveals disparities among communities, especially for vulnerable groups such as long-term care facility residents. We also identified critical roads that are vital for post-flooding access to critical facilities. The results of this research can help inform targeted infrastructure investment decisions and hazard mitigation strategies that contribute to equitable community resilience enhancement.

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The administrator’s dilemma: Closing the gap between climate adaptation justice in theory and practice

Environmental Science & Policy

2022 Justice theory is intended to guide practical choices, but justice theories struggle to inform many decisions that must be made in climate change adaptation practice. This paper highlights gaps between theory and practice by analyzing the justice dimensions of dilemmas routinely faced by adaptation administrators, using the example of property acquisitions to ground the analysis. Justice theories struggle to assist decision-makers in: prioritizing distribution of resources; distributing programs that cause both harms and benefits; weighing uncertain harms and benefits; identifying participants and resolving conflicts in participatory processes; and redressing historic injustices. Proposals to improve adaptation justice that do not address one or more of the practical dilemmas faced by administrators are unlikely to advance the cause. Absent theoretical or policy guidance, decisions are often shaped by administrators’ unconscious heuristics such as views on the role of government and the purpose of buyouts. Tailoring justice-relevant decisions to local contexts may provide greater benefits than a universal approach to justice, but a relative approach is most likely to be just when justice-relevant decisions are transparent and informed by theoretical and empirical work. Transparency is critical for accountability, evaluation, and policy learning. Justice decisions are often constrained by limited authority, resources, and institutional goals, so achieving greater justice in climate adaptation may require changes in the larger governance systems within which adaptation decisions are made. More nuanced evaluations of adaptation justice, more comparative analyses, enabled by greater transparency in practice, and more holistic approaches to adaptation governance are recommended moving forward.

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A global assessment of policy tools to support climate adaptation

Climate Policy

2022 Governments, businesses, and civil society organizations have diverse policy tools to incentivize adaptation. Policy tools can shape the type and extent of adaptation, and therefore, function either as barriers or enablers for reducing risk and vulnerability. Using data from a systematic review of academic literature on global adaptation responses to climate change (n = 1549 peer-reviewed articles), we categorize the types of policy tools used to shape climate adaptation. We apply qualitative and quantitative analyses to assess the contexts where particular tools are used, along with equity implications for groups targeted by the tools, and the tools’ relationships with transformational adaptation indicators such as the depth, scope, and speed of adaptation. We find diverse types of tools documented across sectors and geographic regions. We also identify a mismatch between the tools that consider equity and those that yield more transformational adaptations. Direct regulations, plans, and capacity building are associated with higher depth and scope of adaptation (thus transformational adaptation), while economic instruments, information provisioning, and networks are not; the latter tools, however, are more likely to target marginalized groups in their design and implementation. We identify multiple research gaps, including a need to assess instrument mixes rather than single tools and to assess adaptations that result from policy implementation.

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A systematic global stocktake of evidence on human adaptation to climate change

Nature Climate Change

2021 Assessing global progress on human adaptation to climate change is an urgent priority. Although the literature on adaptation to climate change is rapidly expanding, little is known about the actual extent of implementation. We systematically screened >48,000 articles using machine learning methods and a global network of 126 researchers. Our synthesis of the resulting 1,682 articles presents a systematic and comprehensive global stocktake of implemented human adaptation to climate change. Documented adaptations were largely fragmented, local and incremental, with limited evidence of transformational adaptation and negligible evidence of risk reduction outcomes. We identify eight priorities for global adaptation research: assess the effectiveness of adaptation responses, enhance the understanding of limits to adaptation, enable individuals and civil society to adapt, include missing places, scholars and scholarship, understand private sector responses, improve methods for synthesizing different forms of evidence, assess the adaptation at different temperature thresholds, and improve the inclusion of timescale and the dynamics of responses.

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Education (3)

Stanford University: PhD, Interdisciplinary Environment and Resources 2018

Harvard Law School: JD 2010

Harvard University: AB, Human Evolutionary Biology 2007

Affiliations (6)

  • American Bar Association
  • American Political Science Association
  • American Society of Adaptation Professionals
  • Association of American Geographers
  • Association for Computers and the Humanities
  • Environmental Law Institute

Languages (1)

  • English

Event Appearances (4)

Putting Retreat in Context

Managed Retreat Conference  Columbia University, New York


Ludic Solarites Panel (Solarpunk Climate Fiction)

Situated Solar Relations  Concordia


Community driven relocation as a strategy for a fair adaptation to the climate crisis in Puerto Rico

FEMA Webinar  


Expert Workshop on Climate Sensitivity of Human Mobility

Expert Workshop on Climate Sensitivity of Human Mobility  Potsdam Institute for Climate Impact Research (PIK)