Just like you can't go to modern war in a civil war, war machine, you can't take humanity into its greatest challenge ever in an economic operating system designed only a relatively short time after the advent of the printed book; where virtually everything was made by human hands and skill. It's just that simple.
The following is a direct quote from the Rolling Stone article linked below:
"...With 10 to 13 feet of sea-level rise, most of South Florida is an underwater theme park, including Miami, Fort Lauderdale, Tampa and Mar-a-Lago, President Trump's winter White House in West Palm Beach. In downtown Boston, about the only thing that's not underwater are those nice old houses up on Beacon Hill. In the Bay Area, everything below Highway 101 is gone, including the Googleplex; the Oakland and San Francisco airports are submerged, as is much of downtown below Montgomery Street and the Marina District. Even places that don't seem like they would be in trouble, such as Sacramento, smack in the middle of California, will be partially flooded by the Pacific Ocean swelling up into the Sacramento River. Galveston, Texas; Norfolk, Virginia; and New Orleans will be lost. In Washington, D.C., the shoreline will be just a few hundred yards from the White House.
And that's just the picture in the U.S. The rest of the world will be in as much trouble: Large parts of Shanghai, Bangkok, Jakarta, Lagos and London will be submerged. Egypt's Nile River Delta and much of southern Bangladesh will be underwater. The Marshall Islands and the Maldives will be coral reefs..."