Published in 2A Magazine Issue #45 – Summer 2020

This text is derived from a slide presentation given at the symposium. As such, it is an outline of the presentation incorporating some of the original slides.

A brief review of the American experience on the topic of displacement suggests that it is a constant. Our historybeginning with the nomadic natives of the continent, and continuing with the first European settlers and their moves from east to west, the Africans brought by force and dispersed across the country, the continuing immigration from across the globe, the twentieth century moves from Rustbelt to Sunbelt, the modern flight to the suburbs and the contemporary gentrification of the cities-all can be seen as an ongoing iteration of migration and relocation. To these trajectories can now be added the phenomenon of climate retreat-leaving the places that are subject to the impacts of climate change. Heat, drought, fires, heavy rainfall, increased storm severity, threats to coasts by sea level rise, and inland flooding-all paint a broad geography of vulnerability and risk that will undoubtedly modify established patterns of settlement yet again.

The situation in South Florida presents an opportunity to explore the ramifications of climate retreat. While numerous impacts have been identified, public attention is most easily drawn to the predictions of gradual and permanent inundation, as the evolving condition is already being experienced. A region accustomed to welcoming political refugees and economic opportunists is likely to see the first significant numbers of departures as the impacts of sea level rise intensify (Figure 1).


Climate Change Impacts

Two types of climate change impacts can be distinguished: catastrophic events, such as hurricanes, a historic reality anticipated to increase in severity; and chronic stressors, such as the sunny day flooding already occurring with increasing frequency as rising sea levels alter the water table (Figures 2 and 3).

Catastrophic Events

Recent catastrophic events such as hurricanes, with wind and storm surge causing momentary damage and danger (tornadoes, heavy storms, and fires in other locations), usually evoke a sequence of responses over an extended time frame: rescue and relief, assessment and reporting, recovery, rebuilding, risk reduction, and resilience improvement. These responses all presume a community to rebuild in place. The mobilization of a population for permanent relocation to date has already occurred, and usually through Federal Emergency Management Agency (FEMA) buy outs of neighborhoods after catastrophic floods, such as produced by Hurricanes Katrina and Sandy. As climate change impacts accelerate, retreat from be more common. How to pay for what is expected to be an accelerating need to leave high-risk areas remains a challenge, and raises interesting opportunities for inventing financial vehicles to remove the burden from the public budget. A first step, as a policy goal to reduce the public liability, could be the removal of federal support encouraging building in flood zones.


Chronic stresses

Retreat in response to catastrophic event has generated a certain amount of experience and some understanding of the management required. There is less experience with retreat related to chronic stresses, those recurring conditions, such as flooding due to high tides rather than storms, that may damage but do not necessarily destroy buildings or endanger lives. Researchers are beginning to predict the movements of populations forced to relocate by repeated impact. But how this unfolds is less clear and raises an overwhelming prospect: as more and more people and businesses depart, how can those remaining be sustained? (Figure 4).

The scenarios of decline and departure are writ large in the still unfolding story of Rustbelt towns and cities. Those who can leave, while others are left behind in diminished circumstances. One can interpolate that repeated flooding will lead to: loss of insurance, loss of real estate value, reduction of private debt equity sources and mortgage funding, decline of municipal revenue and bonding capacity, decline of maintenance and abandonment of private property.

Climate Change Response

To further examine both chronic and catastrophic impacts, it is important to understand the distinction between the two essential responses to climate change: mitigation and adaptation.

Mitigation is the term used to describe efforts to slow the rate of change, and to lower the level of stabilization of effects, by reducing carbon and other emissions. Mitigation efforts are generally universal. Emissions are produced by the same generators world-wide, and so can be the efforts to affect the generation. The audience for mitigation is global, and much of the discussion revolves around whether reducing emissions should be affected by altering behavior or technology Adaptation is the term that refers to a response to the impacts of change as they occur-what we must do to live with change. The adaptive response seeks to protect the natural environment and to increase the resilience of the built environment. Adaptation is regionally specific, related to the type of hazard-flooding, fire, etc. In the case of sea level rise, different adaptive response than Miami. By definition, the audience is local, and can elude national attention.

It is generally understood that any mitigation efforts that seek to alter the long-term trajectory of climate change, whether in technology or behavior, have a 30 to 40-year delay for effect. Most of the public discussion about climate change is focused on mitigation precisely because it involves a universal response and thus a broad audience and a unified action. However, it is important to understand that little in this discussion refers to the potential migrations that will occur sooner than the appearance of any positive effect from mitigation actions.

Adaptation is the short-term response required to accommodate the impact as it occurs. In adaptation, regional effects, and therefore regional actions, have three types of response: defense, accommodation, and retreat. These may be sequential, enabling postponement of the disruption of migration, although costly (Figure 5).

The adaptive response to sea-level rise in South Florida includes defense, accommodation, retreat, and cleanup. The first step, to fortify and defend, is something that we have been doing for several decades as we have constantly bolstered our beachfronts with imported sand and the cultivation of beach-preserving grasses. More recent fortifications include raising street elevations and installing pumps. When defense is not possible, accommodation follows: learning to live with periodic flooding, as do the residents of Venice. At some point the chronically stressed context can no longer be sustained, precipitating retreat.

up what we leave behind. What is to be done with the built environments after human use no longer is possible? In the Rustbelt, cities like Detroit and Buffalo, the abandonment became a public liability. In retreat from flooding, whether chronic or catastrophic, the toxic remnants of human habitation remain an environmental hazard. South Florida has a potential opportunity for clean-up. The porous limestone that connects the water table to the sea is a material valued for road base and concrete manufacture; mining rights could be exchanged for cleaning up surface toxicity.

The implementation of any of the above adaptive responses, must take into account three variables related to public decision-making, especially with regard to identifying what and where to defend, and from where and when to retreat. These variables are: geography, economy and politics.

The geography determines the conditions to be dealt within a specific location-Acomplete inundation, frequent flooding, or high and dry ground-clearly setting up competition for the shrinking supply of occupiable ground.

The economic determinants relate to the values of the particular built components that might influence public priorities. Investment for longevity warrants focus on areas of high shared value, such as infrastructure, governmental and institutional properties, and those that host revenue generation from the regional economic drivers, such as tourism on Miami Beach and banking and trade in downtown Miami. Least likely to merit defense are the lower valued western suburbs. A scenario of triage emerges for decision-making about which areas to defend predictability to the prioritization of spending and timing: what and who gets the funding first. Also played out in the political realm is the difficulty of coordinating public infrastructure improvements and adjacent private holdings-often impossible to synchronize, as seen in the elevation of street levels in Miami Beach, where the former first floor of a restaurant has become a basement space with insurance penalties. In the public forum, issues such as community identity and cultural preservation may take on a stronger voice than economic sustainability. Climate gentrification is already a public concern.

The theories and practice of the New Urbanism bring an interesting tool related to the geographical variable of climate adaptation. The Rural to Urban Transect is a theory of the built environment based on the ecological conception of immersive environments. Applied to South Florida, one can identify eight distinct geographical locations or zones of climate impact between the Everglades and the coast, differentiated by the elevation of the land, the geological condition and proximity to the sea (Figure 6).

The multiple scenarios for adaptation from defense through retreat and clean-up, require detailed study to understand impact and response better. One prediction is inarguablethere will be impacts. And although it is not possible to pinpoint the timing of impacts, we are privileged with a foresight that the Rustbelt cities did not have in advance of their decline. Their leaders did not see the advancing decline, did not know what to do when it was upon them, and did not begin to respond until the evolving decline became an evident disaster. In South Florida and along all the U.S. coasts, already one can see impacts of sea level rise.

Scenarios of change, accommodation, and loss need further study, but there is still the opportunity to plan for an orderly retreat (Figure 7).

The human tragedy and social disruption often associated with displacement are not inevitable, and can be avoided by managing the retreat, managing the decline before the departure, and the detritus left behind. And precisely because we have little experience with this process of downsizing, decreasing values, and cleaning up, scenarios of loss must be imagined and tested.

The Biblical Flood teaches of forewarned survival. Today’s unprecedented prescience provides the opportunity to develop strategies for an anticipated future: facilitating the move to a new community for those with limited capacity for re-invention; identifying and preparing recipient communities that would welcome climate retreaters, and the residents and the businesses that employ them; and inventing new financial vehicles to manage financial loss, such as a new tax structure for depreciation, or a transfer of development value by coupling existing community properties with those in a designated community. A design-thinking process could explore a comprehensive series of scenarios played out with different combinations of the variables identified, to learn what needs to be done, who is to do it, and when and how. But even with such a road-map for action, one unpredictable challenge remains: can a society normally rewarded for individual initiative and unaccustomed to political unity, focus on a unified strategy to guide adaptation to climate change and its predicted displacements?