The North Sea Lake?

A paper by workers at the Royal Netherlands Institute for Sea Research has suggested that enclosing the North Sea by 2 giant dams is a technically feasible and affordable means of protecting millions of people from the rise in sea levels that would follow unrestrained climate change (https://www.theguardian.com/environment/2020/feb/12/giant-dams-could-protect-millions-from-rising-north-sea). It would require one dam of 475 km between Scotland and Norway and another of 160 km between SW England and France, at a current total current cost of 750 bn euros. The process would, of course, convert the North Sea into a giant lake with major changes in its ecology (even with giant pumps to expel much of the water from rivers flowing into the area). There would be major changes to North Sea fishing and marine transport systems. It is pretty obvious that there would be major arguments between the countries involved (and others who would benefit) about where the dams were sited and the sizes of the required financial contributions. I suspect that this debate would be more fraught post-Brexit. Strangely enough, some scientists have suggested that the North Sea was once a naturally-dammed, giant lake that was fuelled by melt water at the end of the last glacial period and the bursting of that dam created the channel between England and France.