Vulnerability, adaptation and resilience emerge as complex concepts, resulting from natural as well as human elements. In presence of unavoidable changes that the coastal zone is subjected to, an increase resilience can be viewed as the goal of adaptation policies.

There a numerous determining factors for vulnerability, which include climate and climate change related variables (sea level rise, extreme weather event amplitude and frequency, etc.), morphological variables (terrain relief, erosive potential of the coastal substrate, etc.), demographic and socio-economical variables (population density, income, level lf infrastructure, etc.), as well as social and political variables (effectiveness of institutions, public participation, community cohesion, etc.).

Particular historic trajectories can lead to unexpected outcomes. Bangladesh has very high vulnerability under all the above categories, yet managed to mitigate in a vey effective way the human risk posed by coastal erosion. This contrasts with the great vulnerability which materialized in the United States in the case of Katrina. Even though the United States would be technically and financially able to apply protection measures in New Orleans of the same order as those in the Netherlands, and planned to do so according to the Flood Control Act de 1965, political and administrative vagaries led to a situation where neither adequate physical protection nor workable evacuation plans and emergency response plans were in place when needed.

Scientific knowledge is a necessary, but not sufficient element to generate action. Keeping with the example of New Orleans, in 2001, FEMA hat ranked a hurricane in New Orleans as one of three most likely threats in the USA, with a terrorist attack in New York and an earthquake in San Francisco. In 2004, the simulation of a category 5 hurricane named Pam foresaw in great detail the massive failures of the protection system of New Orleans, that were confirmed a year later by a real hurricane. The well established and documented knowledge was not transformed into action.

Beyond objective and scientific criteria and evaluations, the reinforcement of resilience must address the appreciation and perception of risk, the mobilisation of populations and the different aspects of governance. Unfortunately, public awareness is often only raised in the wake of an extreme weather event. Societies thus have a tendency to protect themselves after the fact and not before. A proactive and inclusive participation and implication of citizen and various actors is essential to initiate a process of reinforcement of resilience. The exclusively to-down approach has shown its limits.

The question of perception and mobilization is also important when faced with gradually evolving symptoms of climate change such as an acceleration of coastal erosion, in sea level rise, the gradual warming and acidification of oceans with its impact on corals and other ecosystems and on fish resources. Even though easily observable and possible to forecast over the long term with some degree of precision, these evolutions do not come with easy adaptation solutions. The protection strategy has limits and entails negative impacts on the coast. Retreat strategies have a high individual and social cost. Accommodation options require a good knowledge of local circumstances. In all cases, the elaboration of adaptation strategies combining protection, accommodation and retreat must be elaborated in a perspective of co-construction between actors and must be informed with founded scientific, as well as traditional knowledge and local observation.

In many coastal zones in the world, rapid development, urbanization, the increased appeal and valuing of the coast has led to development trajectories which are generating risk. The importance of the precautionary principle as an adaptation strategy and a long-term perspective (the seven generations!) as a guiding principle, must be stressed. That is particularly crucial in the presence of climate change and sea-level rise. While our planning horizon is often restricted to a few years, or at best a few decades, science, embodied in this case by the IPCC, anticipates sea level rise up to the end of the century. However, the phenomenon will not stop there but continue for several centuries. Such a time frame is not adapted to political or economic decision-making and goes even beyond out ability to envisage generational ties, but is still relevant from a civilizational point of view. Dealing with climate change thus necessitates a new way of thinking, stepping back to look at things in a wider perspective, with Joël de Rosnay’s famous macroscope and herein also lies a great opportunity as well as a challenge.

  Essential points to remember: 
  1. Vulnerability, adaptation and resilience are three interrelated concepts describing the relation between an environmental (here climatic) stress and the exposed socio-ecological system.
  2. Vulnerability is a function of the physical impacts of environmental or climate change on human (or biological) systems and their adaptation capacity. Detailed definitions vary considerably amongst authors.
  3. It is difficult to measure vulnerability, especially with economic tools, ill suited in many contexts. Indicator-based evaluation methods have been developed and are widely used.
  4. The notions of vulnerability, adaptation and resilience incorporate a temporal dimension when viewed in a systems dynamics perspective.
  5. The four fundamental adaptation strategies are 1) protection, 2) accommodation, 3) retreat, 4) precaution. Often, only the first three are listed.
  6. Each adaptation strategy can be justified in a particular context; the strategies are not mutually exclusive.
  7. Adaptation techniques or tools can be subdivided into several categories (protection, planning, architectural, education, and others), which are often complementary.
  8. The adaptation process unfolds over time and with the participation of all concerned actors.
  9. The perception of the coastal risk is socially constructed and influences the approach to adaptation to climate change.