The study of the impact of global sea-level rise on tides has found that tidal changes will have implications for existing and proposed tidal renewable energy sites.
The research shows that sea-level rise can significantly alter tides across the world in many different ways in both space and time.
The change will be most pronounced in shelf seas on the east coast of the Americas, northwest Europe, north coast of Russia, across Asia and Australasia, according to the study.
The study revealed the change in tides will have an effect on the tidal renewable energy sites, listing the proposed Swansea Bay tidal lagoon as an example of a site that could get less energy from the tide in the Bristol Channel if global sea-level rises by two meters.
However, the tidal change is not always incremental with the sea-level rise and other studies suggest an increase in tidal energy here under a one meter scenario, NOC noted.
Mark Pickering, the lead author who conducted his research at the NOC, said: “An increase in the tidal range at the coast matters as it would make coastal flood events more likely to occur. However, the pattern of changing tides is complex, and in some locations negative changes in tides will decrease flood risk. Changing tides have wide ranging implications from flood risk and tidal renewables to erosion, dredging, and shipping.”
The research was conducted by feeding a range of ‘plausible’ estimates of global sea level rise, considered by the Intergovernmental Panel on Climate Change (IPCC), into a model of global tides.
Scenarios ranging up to 10 meters of sea level rise were tested. However, the results for 0.5, 1 and 2 meters of sea level rise are of the most societal relevance. The study also considered the effect of fixed and receding coastlines and the effect of non-uniform patterns of sea level rise associated with melting of the polar ice sheets.
The study was published in Continental Shelf Research by scientists at National Oceanography Centre (NOC), University of Southampton, and Deltares.