Climate change mobilizes urban PAHs into systemic environmental risks (SERisks)

Area of Science:

• Environmental Science
• Urban Sustainability
• Climate Change Impacts

Background:

• Urban sustainability management must address legacy pollution, particularly Polycyclic Aromatic Hydrocarbons (PAHs), which are increasingly destabilized by climate change.
• PAHs, once considered stable soil pollutants, are now understood as dynamic reservoirs interacting with multiple environmental media.

Purpose of the Study:

• To synthesize existing research on the impact of climate change on PAH dynamics in urban soils.
• To reframe urban PAH contamination as climate-amplified systemic environmental risks (SERisks).
• To propose a framework for adaptive governance of these emerging risks.

Main Methods:

• A comprehensive synthesis of over 190 studies examining PAH behavior under changing climatic conditions.
• Analysis of empirical data and scenario-based modeling to predict future PAH mobilization.
• Identification of key challenges in understanding PAH mobility and governance.

Main Results:

• Extreme climate events (heatwaves, droughts, intense rainfall) disrupt soil-pollutant equilibria, causing significant PAH remobilization.
• Climate extremes can lead to order-of-magnitude increases in PAH mobilization and intensify cross-media transfer.
• Legacy soil PAH reservoirs are becoming increasingly responsive to climate variability, acting as secondary sources.

Conclusions:

• Urban PAH contamination presents climate-amplified systemic environmental risks (SERisks) due to nonlinear transport and feedback mechanisms.
• Effective governance requires improved understanding of PAH mobility, climate feedback loops, and adaptive management tools.
• A proposed SERisks governance framework emphasizes real-time monitoring, early warning systems, and AI-assisted decision support for integrated risk management.