Rising sea levels represent a ‘chronic threat’ to European coastal regions, profoundly affecting environmental governance and economic development. All maritime basins surrounding Europe are impacted, albeit with distinct regional characteristics. Managing this phenomenon requires integrated planning that balances economic, social, and environmental objectives.
This is the conclusion of the 1st European assessment report on sea level rise, a document developed over three years through the Knowledge Hub on Sea Level Rise (KH-SLR), an initiative supported by nine European countries, including Italy.
Rising Sea Levels: Record Levels in the Mediterranean
The average rate of sea level rise in Europe slightly exceeds the global average and is accelerating. However, there are significant regional variations:
- Baltic Sea: Some areas exhibit lower or even negative rates due to vertical land movement (e.g., isostasy, the uplift of land following glacial melt).
- Southern Areas, such as the Mediterranean: Higher sea level rise rates are expected. Future projections are heavily influenced by greenhouse gas emission scenarios: higher emissions will lead to faster rates of rise and more severe impacts.
The report also warns of changes in Medicanes (Mediterranean tropical-like cyclones) and meteotsunamis (high-frequency ocean waves caused by rapid atmospheric pressure changes). These are driven by rising sea surface temperatures and altered atmospheric circulation patterns, increasing risks for coastal regions.
Coastal areas will also face severe erosion. By the end of the century, at least 20% of Mediterranean beaches are projected to lose more than 50% of their area.
Four Approaches to Address Sea Level Rise
The study identifies four strategies to mitigate the impacts of rising sea levels:
1. Adaptation
This approach focuses on learning to live with sea level rise. Measures include:
- Making buildings flood-resistant (e.g., using waterproof materials).
- Strengthening critical infrastructure to withstand extreme events.
- Implementing early warning systems and climate risk insurance.
2. Protection
Protection measures aim to reduce coastal hazards using:
- Hard defenses: Infrastructure such as dikes, seawalls, or artificial barriers.
- Nature-based solutions (NBS): Restoring ecosystems like marshes, coral reefs, or dunes to absorb wave energy and mitigate flood risks.
3. Advancement
This strategy involves creating new land or expanding existing areas to counteract flooding and erosion. Examples include:
- Conservation and restoration of coastal ecosystems.
- Projects to build new coastal areas, such as artificial islands.
4. Retreat
The retreat approach seeks to move human activities, infrastructure, or entire communities away from high-risk zones. It can involve:
- Planned relocation: Moving populations and resources to safer areas.
- Managed realignment: Strategically altering land use to reduce exposure.
While effective in reducing risk, this strategy poses difficult trade-offs, as it can entail significant economic and social costs.
These approaches, when combined with integrated planning, aim to address the challenges posed by rising sea levels, particularly in vulnerable regions like the Mediterranean.