Rising Seas - Barriers to monitoring and communicating the risks

The publication in August 2021 of the report of Working Group 1 of the Intergovernmental Panel on Climate Change (IPCC) bolstered evidence that global mean sea level continues to rise, accelerating from an average increase of around 1.3 mm y-1 in the early 20th Century, to roughly 3.7 mm y-1 between 2006 and 2018 (IPCC, 2021). Such increases were ascribed in almost equal measure to thermal expansion of the oceans (50%) and the melting of landbased ice sheets and glaciers (43%), both of which are a consequence of climate change, with a smaller contribution due to changes in water storage on land. Importantly, the report highlighted that sea level will continue to rise, because of the slow ocean response time to climatic warming, with estimated likely increases of between 0.38m and 0.77m by 2100, depending on which combination of future greenhouse gas emissions, pollution controls and socioeconomic assumptions is used.