But you just said that it's about people, and that everyone will only start to care about the problem when everyone is up to their necks in water.
But let's say it's really all about money. We are the richest country in the world. If we just took the money that we spend on entertainment every year, and don't change a single other thing, that gives us $360 billion a year - a trillion dollars every three years. That's enough for a lot of solar farms, nuclear power plants, battery energy storage systems, pumped hydro, brine mining, charging networks etc.
Don't want to give up entertainment? Then just take direct action. Refuse to buy gasoline. We will immediately cut emissions by at least 35%. Or never go anywhere without two people in the car. That reduces it by 16% - and costs nothing other than convenience. AND it ends traffic problems, parking issues and inner city pollution issues.
Or just take the train. (And of course build more trains,)
It is the height of stupidity to wait until the cost of preparation rises to the point where we can only afford to do that - and then do nothing BUT that. To go back to the boat analogy, it's absurd to wait until the only option is lifeboats in the middle of the North Atlantic, and only then consider doing something because then your life is in danger. Because by then a lot of other people will already have died, even if First Class isn't underwater yet.