Managed retreat involves the purposeful, coordinated movement of people and buildings away from risks. This may involve the movement of a person, infrastructure, or community. It can occur in response to a variety of hazards such as flood, wildfire, or drought. Politicians, insurers, and residents are increasingly paying attention to managed retreat from low-lying coastal areas because of the threat of sea level rise due to climate change. Trends in climate change predict substantial sea level rises worldwide, causing damage to human infrastructure through coastal erosion and putting communities at risk of severe coastal flooding.
Tollesbury Managed Realignment site in Essex, the first large-scale attempt at salt-marsh restoration in the UK
Freiston Shore Managed Realignment site, Lincolnshire
Between 1901 and 2018, average global sea level rose by 15–25 cm (6–10 in), an average of 1–2 mm (0.039–0.079 in) per year. This rate accelerated to 4.62 mm (0.182 in)/yr for the decade 2013–2022. Climate change due to human activities is the main cause. Between 1993 and 2018, thermal expansion of water accounted for 42% of sea level rise. Melting temperate glaciers accounted for 21%, while polar glaciers in Greenland accounted for 15% and those in Antarctica for 8%.
Jason-1 continued the sea surface measurements started by TOPEX/Poseidon. It was followed by the Ocean Surface Topography Mission on Jason-2, and by Jason-3.
Between 1993 and 2018, the mean sea level has risen across most of the world ocean (blue colors).
The Ross Ice Shelf is Antarctica's largest. It is about the size of France and up to several hundred metres thick.
Thwaites Glacier, with its vulnerable bedrock topography visible.