Scientists have proposed mammoth structures to enclose the North Sea and protect tens of millions of Europeans from rising sea levels due to climate change. The urgency of the crisis is emphasized by the scale of the project, which would be one of the largest engineering feats ever attempted. The estimated cost is between $250 billion and $550 billion, which could potentially be covered by Northern European countries. Some experts are skeptical, suggesting that building defenses along the coastline might be a better solution. The scientists behind the proposal see it as a warning and hope it serves as a reminder of the drastic actions that may be necessary if global leaders fail to address climate change. The preferred solution, they say, is to reduce CO2 emissions and curb global warming to avoid the need for such extreme measures. If nothing changes, millions of people could become climate refugees due to sea level rise. Coastal cities like San Francisco and Manila are still dealing with the impacts of rising sea levels. A proposal for massive barriers connecting Norway to Scotland and France to England aims to protect tens of millions of Europeans from the threat of flooding. By 2050, around 150 million people in low-lying coastal areas could be at risk of being submerged. The proposed barriers would be much larger than existing sea walls and would require a massive amount of sand for construction. Building such structures would have significant ecological and economic consequences, but as sea levels rise, the options for protecting vulnerable areas are becoming limited. The Netherlands, a country with extensive experience in managing flood risks, views the proposal as extreme but necessary for the future. However, he emphasized that there are no easy answers when discussing the potential for a significant rise in sea levels.