The assessment was published in a special issue of Natural Hazards and Earth Systems Sciences exploring why the flood risk in Venice has recently increased. Risk is expected to continue growing, perhaps even accelerating, through the 21st century.
Among the key factors when considering flood risk in coastal cities such as Venice is projected relative sea level rise; the change in sea level relative to the local solid surface of Earth. This accounts for ground sinking and mean sea level rises. Long-term future projections indicate significant uncertainty in the relative sea level of Venice: between 17 and 120cm by 2100. Study author Professor Davide Zanchettin attributes this to the challenges of projections based on a wide range of possible emissions scenarios and to uncertainty about the relevant physical processes.
“For a projection to be useful, it must be well constrained,” he said. “There are important feedbacks in the climate system, for instance...