Navigating the unknown: Nature-based solutions for coastal climate adaptation under deep uncertainty

Area of Science:

• Environmental Science
• Climate Change Adaptation
• Coastal Management

Background:

• Coastal adaptation strategies are crucial for managing climate change impacts.
• Nature-based solutions (NbS) present multifunctional alternatives to traditional hard-engineered defenses.
• Limited adoption of NbS is observed despite their potential benefits under uncertainty.

Purpose of the Study:

• To investigate how deep uncertainty influences the planning and management of nature-based solutions for coastal adaptation.
• To identify specific uncertainties affecting decision-making processes for NbS adoption.
• To explore the implications of these uncertainties for the long-term viability of NbS.

Main Methods:

• Conducted unstructured and semi-structured interviews with Dutch experts in coastal NbS, adaptation, and decision-making under deep uncertainty.
• Categorized identified topics of deep uncertainty into system understanding, outcome probabilities, and outcome prioritization.
• Analyzed the interactions between deep uncertainty and NbS characteristics.

Main Results:

• Key uncertainties include the rate of sea-level rise and political acceptance of flood risk.
• NbS show promise as adaptive, multifunctional short-term interventions.
• Long-term NbS potential is constrained by uncertainties in climate impacts, performance, conflicting functions, and risk acceptance.

Conclusions:

• The adaptivity and multifunctionality of NbS, while beneficial short-term, introduce long-term uncertainty and risks of lock-in.
• Effective coastal adaptation requires integrating political and technical scenario planning to navigate NbS trade-offs.
• Balancing uncertain multifunctionality with predictable flood prevention is vital for resilient long-term coastal management.