Sea level rise is a major threat to coastal communities and ecosystems. It increases the risk of storm surges, floods and erosion that damage or destroy buildings and roads, disrupt natural habitats and erode the foundations of social services, including health care and education. It can also contaminate drinking water and exacerbate the spread of waterborne diseases in affected areas.
Rising seas are caused mainly by melting glaciers and ice sheets, and the thermal expansion of ocean water as it warms. However, human activities can also contribute to rising seas by draining or pumping out groundwater, which reduces freshwater supplies and thus adds saltwater to local lakes and rivers.
Global sea levels are changing and the rate of change is accelerating. Sea level changes at specific locations on land may be more or less than the global average due to local factors, such as ground settling, upstream flood control, erosion, regional ocean currents and whether the land is still rebounding from the compressive weight of vanished Ice Age glaciers.
For low-lying countries and islands, the risks are severe. They may be forced to relocate, affecting the quality of their living environment and economic activity. This can lead to mental health effects ranging from eco-anxiety and solastalgia (a feeling of loss or alienation) to anxiety, depression and post-traumatic stress disorder. In addition, the increased frequency of flooding and mudslides can disrupt food production and cause the loss of infrastructure such as roads, health facilities and schools.