Without additional climate change adaptation measures, the annual cost of damage from coastal flooding in Europe could jump from $1.4 billion today to as much as $1 trillion by the end of the century due largely to rising sea levels, according to a new analysis published in the journal Nature Climate Change. These coastal floods could impact up to 3.65 million people in Europe annually by 2100, compared to 102,000 today.

The study examined how Europe’s 62,000 miles of coastline would be impacted if sea levels rose 0.5 to 2.5 meters (1.6 to 8.2 feet). Coastward migration, urbanization, and rising land and infrastructure values have been the main drivers of increasing flood losses to date. But in the coming decades, these factors will be replaced by climate change as the primary driver for the projected rise in costs from coastal flooding.

The research, led by scientists at the European Commission’s Joint European Research Center in Italy, estimates there will be a 30-fold increase in annual coastal flood damages in Europe by 2050 and a 700-fold increase by 2100 if the region does not drastically expand its coastal flood protection systems.