I had an a-ha about this issue.
I have been thinking about climate refugees and the political instability that they will bring. It is this issue that the Department of Defense has called out as the greatest threat coming from climate change and sea rise. In my mind, I had always equated that with a place like Bangladesh, which has large portions of its land that will become flooded with a one-meter rise in sea level.
Yesterday I heard a story that spoke to the issues causing the migration of people out of Central America and attempting to enter the United States. It called out the fact that one of the reasons is a lack of drinking water and failing crops — due to climate change. If you think about it, what would cause you to get up and move to another country, leaving behind what material goods you might have, family and friends? To do that you have to be pretty desperate.
The sooner we recognize all the impacts for people attempting to enter the United States, then we'll be able to address the issue more effectively. Personally I don't think sea walls will be that effective against sea rise and border walls, while having some impact, won't stop desperate people.
Would they stop you?