We knew this was coming, we knew if we didn't stop pumping CO2 into our atmosphere we would have to mitigate a lot of the damage at much greater cost and yet here we having increased the rate at which we increase CO2 into the atmosphere to now a whopping 3.3 ppm annually and we have spent nothing on mitigation. Honestly it feels like our governments just chose we were all going to die and were fine with it.
Easier said than done. They basically need infrastructure to handle months (average month before 2000) of rain falling in a few days over several countries. Huge storm canals, dams and water basins that can divert and hold up to half a year of rain and that's assuming climate change doesn't make it even much worse in a decade.