Assessing Coastal Flood Risks to European Critical Infrastructure under Different Global Warming Levels

European coastal regions host an extensive network of roads and railways that support economic activity and urban development. The European Union is working to complete its Trans-European Transport (TEN-T) core network by 2030, the extended core network by 2040, and the comprehensive network by 2050. A large share of this infrastructure development will happen in coastal areas. Global warming is expected to lead to large increases in coastal flood risk. For the European transport systems, this potential increase remains largely unknown. There is a clear need for better risk assessments to ensure sustainable infrastructure planning and management. Traditional risk assessment methods typically use gridded land use maps to quantify affected transport networks, treating them as raster data. This approach tends to overestimate risks. Additionally, uncertainties associated with damage functions and asset valuation further reduce confidence in risk quantification. Our study treats transport infrastructure as vector data and integrates type-specific damage functions and asset valuations for roads and railways to provide a fully probabilistic assessment of coastal flood risk to Europe’s roads and railways for global warming levels spanning 1.5°C to 4°C. Our findings show that, on average, approximately 1,500 km of European transport networks are exposed to coastal flooding annually under baseline (1980-2020) climate conditions, causing estimated damages of up to €730 million per year. Risks rise substantially with increasing global warming. If global warming reaches 1.5°C or 2°C above the pre-industrial levels by the end of 21^st century, the expected annual damage is projected to increase by ~55% compared to baseline. At 3°C of global warming, damages would rise by ~85%, and at 4°C, by ~100%, compared to baseline. The countries most affected across all considered warming levels in absolute numbers include the UK, Italy, Norway, France, and Denmark. Our results indicate that most European countries will need to allocate a greater share of their transport budgets to manage growing coastal flood risks with increasing global warming. Limiting global warming to the Paris Agreement’s targets offers significant financial benefits.