Seven Lessons from The Watchman’s Rattle for Coastal Erosion and Community Resilience

Rebecca Costa’s The Watchman’s Rattle: Thinking Our Way Out of Extinction explores why societies struggle to solve complex problems even when the evidence is clear and the stakes are high. The title refers to the wooden rattle carried by medieval night watchmen, shaken to warn the town of approaching danger — a metaphor for the early warning signs that societies often ignore until it is too late. Costa argues that complexity can exceed our cognitive limits, leading to paralysis, denial, and comforting narratives that replace evidence-based action. Although she writes about civilisations and global risks, her insights apply powerfully to the accelerating challenges faced by coastal communities today.

Changes can take place too quickly for engineered solutions requiring temporary measures and with a devastating impact on the salebility of properties

1. Complexity Outpaces Our Ability to Respond

Coastal erosion is not a single, tidy problem. It is the convergence of rising sea levels, intensifying storms, sediment shortages, ageing defences, and long-standing planning decisions. These forces interact in unpredictable ways, creating a level of complexity that can overwhelm even well‑resourced institutions. Costa’s work reminds us that when complexity grows faster than our capacity to understand it, we instinctively reach for simplified explanations. Yet erosion rarely behaves in simple, linear patterns. It accelerates, shifts, and surprises, demanding a more nuanced and adaptive mindset. This is a challenge for many parts of Britain - see below.

2. Tipping Points Arrive Quietly, Then All at Once

Costa’s metaphor of the watchman’s rattle — the early signal of danger — is particularly apt for coastal systems. A narrowing beach, a defence wall that overtops more frequently, or a cliff that begins to shed material after heavy rain are all subtle warnings. The danger lies in assuming that past behaviour predicts future stability. Coastal systems can appear unchanged for decades before crossing a threshold that triggers sudden, irreversible loss. Recognising tipping points early is not alarmist; it is essential to safeguarding communities.

Sea defences overwhelmed. Wire mesh that once contained rocks now broken and washed down the beach

3. Belief Replaces Evidence When Complexity Overwhelms

When faced with problems that feel too large or too fast-moving, people often retreat into belief rather than evidence. In coastal settings, this can take the form of nostalgia for a coastline that no longer exists, faith that “the sea will sort itself out”, or denial that climate change is altering local risk. These responses are deeply human — they offer comfort in the face of uncertainty — but they can delay necessary adaptation. Costa’s work encourages us to acknowledge these psychological patterns and to create spaces where evidence can be heard without dismissing the emotional realities people face.

4. Gridlock Signals Cognitive Overload, Not Indifference

Coastal erosion decisions often stall for years. This is rarely due to apathy. More often, it reflects the sheer complexity of the system: fragmented responsibilities, competing priorities, limited funding, and political risk. Costa describes this as institutional paralysis — a sign that the problem has outgrown the structures designed to manage it. Breaking gridlock requires governance that matches the complexity of the challenge, enabling collaboration rather than competition between agencies, landowners, and communities.

5. Over‑Specialisation Obscures the Whole System

Costa warns that when experts become too specialised, they lose sight of the wider system. This is particularly true along the coast. Engineers focus on defences, ecologists on habitats, economists on cost–benefit ratios, and residents on home and heritage. Each perspective is valid, yet none is sufficient alone. Coastal resilience demands a systems view — an understanding of how natural processes, infrastructure, culture, and risk perception interact. When disciplines collaborate, solutions become more imaginative, more adaptive, and more enduring.

6. Physical Resilience Must Be Matched by Psychological Resilience

One of Costa’s most important insights is that human cognition is part of the system. Coastal adaptation is not only about sea walls, dune restoration, or managed realignment. It is also about supporting communities as they navigate uncertainty, loss, and change. People need honest communication about risk, opportunities to shape adaptation plans, and support when relocation becomes necessary. They also need space to grieve landscapes that are changing. A community that feels informed, included, and supported is far more capable of facing difficult transitions than one that feels ignored or overwhelmed.

7. Cognitive Innovation Is Essential for a Changing Coastline

Costa argues that the way forward lies in extending our thinking beyond its biological limits. For coastal communities, this means embracing tools and approaches that help us see the bigger picture: modelling that illuminates future risks, adaptive pathways that allow for flexibility, nature‑based solutions that work with natural processes, and governance structures that evolve as conditions change. It also means fostering local creativity and leadership, recognising that communities themselves often hold the most practical knowledge about their coastlines.

Hearing the Rattle Before the Storm

Coastal erosion is one of the clearest examples of Costa’s thesis: a complex, accelerating threat that tests the limits of our cognition and institutions. Yet it is also an arena where communities can demonstrate extraordinary resilience, imagination, and solidarity. If we listen for the watchman’s rattle — the early signs of strain, denial, and tipping points — we can act before crisis becomes collapse. And if we pair physical adaptation with psychological support, we can help coastal communities not only survive change, but shape it with purpose and dignity.