It’s pretty self explanatory that the sea levels are rising. According to Wikipedia the 3 main reasons for sea levels rising are “oceans expand, ice sheets lose ice faster than it forms from snowfall, and glaciers at higher altitudes also melt”.
By 2050, the sea levels are estimated to rise 5-8 inches so to prevent this flooding NASA will build a large dome around the island to prevent the flooding in future years.
According to cbs news, major costal cities are estimated to be flooded by 2050. CBS news states that “over 3000 million people will be waterlogged in just 30 years”