Sure, it's reasonable to discuss, and I'm all for "climate planning" to the extent we look at how placing future infrastructure to account for potential future changes. We have been pretty crappy at that over the last few hundred years, again, because humans have a problem seeing past a few generations or that there was a time when humans couldn't have even breathed the Earth's atmosphere. We were crappy at it for thousands of years beforehand as well, but older infrastructure was (mostly) easier to move or rebuild. When Death Valley turned from temperate paradise to blazing desert, the native inhabitants there just packed up and moved over time. That would be a bit harder to do for NYC. And certainly I'm not in favor of tire fires as a power source. I'm all for exploring alternative energy reasonably without the ZOMG!.
Dyson's (and other scientists in the appropriate disciplines) speculations are that the models favored by one side of the argument use faulty data and need work. The creators of those models would argue that the models that refute them use faulty data. That's one of the points. People are just as sure of their models now (across the spectrum) as people were about their models in the '70s. In the end though (IMO) it's all a "human" argument versus a "planet" argument.
Very little that we build today is meant to last more than 100 or 200 years (or less). Much of it could be maintained to last longer, but too many factors we can't predict or don't know prevent building to last longer plus cost is always a factor. We all can't build our houses out of stone blocks nor can we all own land that is stable enough.
If the oceans were to rise a few feet, we would just rebuild further inland. The change would be likely be gradual and most infrastructure would be rebuilt in that time anyway. The economic incentive to maintain industry and ports on the coast would mean those things would be rebuilt. Likely new areas would become that best shipping ports and old port areas would be abandoned to become good fishing areas. Honestly, it would all probably be rebuilt piecemeal as things are affected by hurricanes and other storms that already happen. Flooded cities would rust away within decades and people would move as industry moved.
The biggest issue I have with the predictions is the more ambitious predicted major changes in 10 or 20 years when there was no real evidence for that. If this is going to happen, it will happen on many decades to hundreds of years. We have time. Which means 1) we have no idea if our industry in 100 years will look anything like it does now, and 2) we may not be able to differentiate change due to global warming from natural changes that would have happened anyway.
