The IPCC report uses this data first to show that the population potentially exposed to a 100-year coastal flood is projected to increase by about 20% if global mean sea level rises by 0.15 m relative to 2020 levels. This exposed population doubles at a 0.75 m rise in mean sea level and triples at 1.4 m without population change and additional adaptation. Using the sea level rise scenarios from the IPCC working group I the timing of exceedance of risk increase can be assessed.

Population at risk of coastal flooding to a 100-year event. The size of the circle represents additional people at risk per IPCC region compared to the people currently at risk and the colour shows the timing. Darker colours indicate earlier risks. The left side of the circles shows absolute population at risk and the right side shows the share of the population in percentage. Results also used in IPCC Technical Summary (IPCC, 2022).

Based on, amongst others, this data the recent synthesis report also highlights that increasing urbanisation in low-lying and coastal zones will be a major driver of risk increase to sea level rise.

IPCC figure showing near-term projected increase of population exposed to 100-year flooding events depicted as the increase from the year 2020 to 2040 (due to sea level rise and population change), based on the intermediate GHG emissions scenario (SSP2-4.5) and current adaptation measures. Out-migration from coastal areas due to future sea level rise is not considered in the scenario.

BlueEarth Data

It is now also possible to explore the data from multiple scenarios in BlueEarth Data platform. The BlueEarth Data platform, developed by Deltares, is a free, web-based application designed to facilitate the study and sharing of integrated water and subsoil-related data. Primarily intended for professional specialists and researchers, the platform offers indicative data through a multi-data viewer, covering various themes such as Flooding, Coastal Management, and Offshore. Users can access global datasets, visualize spatial maps and time series, and even download selected data after registration.

”We are delighted to host the IPCC data on populations at risk of coastal flooding due to a 100-year event on our platform. Our aim is to provide users with the opportunity to engage with this crucial data in greater detail,” says Björn Backeberg, Deltares expert and product owner of the BlueEarth Data Platform.

Deltares researcher Gundula Winter: "I am very excited that we can share the full dataset through BlueEarth now. In the IPCC report, we could only present a subset of the data. BlueEarth allows people now to access the whole dataset and compare scenarios for different Shared Socio-economic Pathways".

A detailed description of the methods and references can be found in the original paper, in Climate Risk Management issue 34 (Long-Term Sea-Level Rise Necessitates a Commitment to Adaptation: A First Order Assessment).

Share this page.