1) Migrating an entire city's population elsewhere is a MASSIVE undertaking. Not just in cost, either; we're talking about uprooting an entire population's lives and moving them elsewhere, which has all kinds of social problems. Look at New Orleans and Katrina for a great example of this. Under your strategy, pretty much the whole city should have just been abandoned and rebuilt elsewhere, but for the people who lived and worked there, this simply wasn't even on the table psychologically.
2) How do you propose to both earmark enough funds for realistic relocation/rebuilding efforts, and keep those funds safe from political interests over the span of 100+ years. It's been damn near impossible to keep Medicaid and Social Security funding in place, and those are being used by millions of people every day. "Rainy day" funds are an easy target for reallocation when budgets start getting tight.
Realistically, I think we're going to see individual cities deal with this in different ways, mostly on their own.
It is a massive undertaking, but probably less of an undertaking than bringing carbon emissions down to acceptable levels. Estimates of the latter run from around $300B [1][2] to $2T [3] to around $2.5T [4] per year. By comparison, estimates on the total cost of Hurricane Katrina rebuilding usually run around $125B. [5][6]
As for earmarking funds - one possible mechanism might be a carbon tax + insurance subsidy. The idea is to tax carbon emissions at a rate that is lower than what mandatory carbon reductions would cost, but higher than the expected value of new natural disaster rebuilding. Some of the proceeds would be distributed to existing insurance companies, which already have expertise in both investing and in paying out claims. Normal market discipline keeps this industry competitive, which eliminates the waste that would accrue if a government bureaucracy were created to do the work.
Regardless, we should have comprehensive evacuation plans for each major city worked out. That sort of work costs barely anything and has big payoffs in a lot of situations.
1) Migrating an entire city's population elsewhere is a MASSIVE undertaking. Not just in cost, either; we're talking about uprooting an entire population's lives and moving them elsewhere, which has all kinds of social problems. Look at New Orleans and Katrina for a great example of this. Under your strategy, pretty much the whole city should have just been abandoned and rebuilt elsewhere, but for the people who lived and worked there, this simply wasn't even on the table psychologically.
2) How do you propose to both earmark enough funds for realistic relocation/rebuilding efforts, and keep those funds safe from political interests over the span of 100+ years. It's been damn near impossible to keep Medicaid and Social Security funding in place, and those are being used by millions of people every day. "Rainy day" funds are an easy target for reallocation when budgets start getting tight.
Realistically, I think we're going to see individual cities deal with this in different ways, mostly on their own.