Sea level is rising as a result of ocean heating (thermal expansion) and land ice-mass loss (Greenland and Antarctic ice sheets and glaciers) due to climate change. About 30% of global mean sea level rise can be attributed to ocean thermal expansion and 70% to land ice melt.  Average global sea level has risen by more than 8 cm since the early 1990’s and it continues to rise at a rate of 3.3 mm each year.  Sea levels do not rise homogeneously. Some regions are more threatened than others. Climate models project a global mean sea level rise (GMSL) during the 21st century that will likely be in the range of 0.29-0.59 m for a low greenhouse gas emissions scenario and 0.61-1.10 m for a high one. 
Sea level rise can seriously affect human populations in coastal and island regions as well as natural environments such as marine ecosystems. Impacts of sea level rise include coastal flooding and coastal erosion as well as saltwater intrusion into groundwater and agricultural soils.  Each year around 100,000 people are exposed to coastal flooding in the European Union. In the absence of adaptation, this number is projected to reach 1.6 - 3.9 million by the end of the century. 
The implementation of climate adaptation measures is therefore key. Adaptation options include grey measures (technological and engineering solutions), green measures (nature-based approach) and soft measures (policy, legal, social, management and financial measures that can alter human behaviour and styles of governance).  Nature-based solutions can efficiently contribute to flood protection and provide multiple other benefits including increased CO2 storage, restoration of biodiversity, and recreational opportunities.  On 24 February 2021, the European Commission adopted a new EU Strategy on Adaptation to Climate Change. It provides details on measures to forge a climate-resilient Union and to step up international action for climate resilience. Measures towards developing a climate-resilient Union are classified in three categories:
- Smarter adaptation: Improving knowledge and managing uncertainty
- More systemic adaptation: Support policy development at all levels and sectors
- Faster adaptation: Speeding up adaptation across the board
As highlighted under point 1 above, a good understanding of climate change impacts is essential for efficient climate change adaptation. Copernicus and the European Marine Observation and Data Network (EMODnet) have a key role to play in making data available. With the European Atlas of the Seas, this information is easily accessible to everyone. Dive in and explore the Map of the Week to learn about global mean sea level regional trends!
The data in this map are provided by Copernicus Marine Services.