Popular extreme sea level metrics can better communicate impacts

Area of Science:

• Climate Science
• Oceanography
• Coastal Engineering

Background:

• Extreme sea levels (ESLs) are critical indicators of climate change impacts.
• Understanding ESL changes is vital for assessing risks to human and natural systems.
• Current global metrics often lack local context, hindering effective risk communication.

Purpose of the Study:

• To demonstrate the need for contextualizing extreme sea level (ESL) hazard projections.
• To highlight the importance of integrating local sea level rise (SLR) projections with population exposure data.
• To advocate for a simultaneous assessment of hazard, vulnerability, and exposure in climate reports.

Main Methods:

• Utilized a flood exposure model incorporating local sea level rise projections.
• Incorporated population exposure estimates for 414 global cities.
• Analyzed the timing of projected ESLs crossing critical infrastructure thresholds.

Main Results:

• Global summary metrics for ESL changes often lack local exposure and vulnerability context.
• Contextualization is essential for understanding the societal implications of ESL changes.
• Specific examples illustrate the necessity of integrating local data for accurate risk assessment.

Conclusions:

• Regional and global climate assessment reports should integrate global, regional, and local perspectives on coastal risk.
• Addressing hazard, vulnerability, and exposure simultaneously is key to effective coastal risk management.
• Enhanced contextualization of ESL projections is needed for informed policymaking and public communication.