Impacts from sea-level rise are among the most crucial impacts of climate change. Global sea levels have been rising in the past century, and will almost certainly accelerate through the 21st century and beyond due to global warming (Nicholls, 2010).
The mean rate of sea-level rise from 1993 to 2009 measured by satellites has been 3.3 +/-0.4 mm per year (Ablain et al., 2009). The estimates for future sea-level rises by 2100 diverge, yet have generally increased in projected rises since the publication of the Fourth Assessment Report of the IPCC in 2007. Such newer estimates now range from approx. 30 to approx. 200cm, depending on the assumed future developments that in turn drive climate change. Changes in the large sea currents and regional processes such as sediment accumulation or drainage and groundwater withdrawal can respectively offset or exacerbate these rates. The main impact of sea-level rise is submergence of land, i.e. “land loss”, and increased flooding in coastal areas. Such direct biophysical impacts can cause a variety of socioeconomic impacts, which are considered to be overwhelmingly negative (Nicholls, 2007). This map focuses on the number of people that would be affected by a submergence of land triggered by a 1m sea-level rise.
The map displays the number of people per administrative unit that are potentially at risk if a global mean sea-level rise of 1m occurred.
- Please avoid over-interpreting the maps. Maps only have a certain explanatory power. For example, the data presented on the interactive world map is not applicable for highly localized projections, forecasts, and “ground truthing” events and processes there.
- Please make use of the ci:grasp glossary to clarify terms you are unfamiliar with. Please file a request for features (link) if we have missed to explain a term in our glossary
- It is helpful to discover whether and where adaption measures are currently taking place, and what type of impacts they address. You can search for them via the interactive world map’s adaptation filters, and combine them with an impact map. Alternatively, you can search for adaptation projects via the list of projects.
- Please refer to the ci:grasp list of references for an ample body of scientific literature. The references in the text throughout the platform are collected there.
This map builds on the results from estimations of the potential land loss, i.e. land that will be inundated, due to 1m sea-level rise. The adjusted GRUMP version 1 dataset for global population in 2000 was used to analyze potential population at risk of migration due to sea-level rise. It was assumed that the population is uniformly distributed within a grid cell, i.e. a single value for population density in a grid was applied. The population density was calculated by dividing the population by the area of the grid cell. The area of the land that could be inundated due to 1m sea-level rise within the grid cell was calculated based on previous estimations of the potential land loss. By multiplying the population density in a grid cell with the flooded area within this grid cell, the potential population at risk of migration was calculated.
|Global Administrative Areas||GADM version 1.0||2009||2nd level administrative unit||http://www.gadm.org|
|Global Population||Global Rural-Urban Mapping Project (GRUMP), Version 1 alpha data: Urban/Rural Area GRIDS||People counts||2004||1km||http://sedac.ciesin.columbia.edu/gpw/|
|Elevation||SRTM 90 dataset version 4.1||2008||90m||http://srtm.csi.cgiar.org|