It would become a MASSIVE capital idea IF “climate change” whatever it becomes is not (as we expect it will not be) a massive global catastrophe, even if Greenland becomes much more warmer on average than today. The possibilities could be huge.
But, what will they do to get the money? Sell a special edition of U.S. bonds with the dividend rate variable to the economic possibilities with Greenland? Would the bonds then be paid off out of royalty revenue on federal leases of land for mineral and fossil fuel exploration, development and production in Greeland.
And if all that is true and possible, then would Denmark even want to sell Greeland?
I think the idea is on one level great, and on another level impractical.
“Trump’s Folly”
In 1979, Denmark granted home rule to Greenland, and in 2008, Greenlanders voted in favor of the Self-Government Act, which transferred more power from the Danish government to the local Greenlandic government.
Under the new structure, in effect since 21 June 2009,[19] Greenland can gradually assume responsibility for policing, judicial system, company law, accounting, and auditing; mineral resource activities; aviation; law of legal capacity, family law and succession law; aliens and border controls; the working environment; and financial regulation and supervision, while the Danish government retains control of foreign affairs and defence. It also retains control of monetary policy, providing an initial annual subsidy of DKK 3.4 billion, which is planned to diminish gradually over time. Greenland expects to grow its economy based on increased income from the extraction of natural resources.
The capital, Nuuk, held the 2016 Arctic Winter Games. At 70%, Greenland has one of the highest shares of renewable energy in the world, mostly coming from hydropower.
https://en.wikipedia.org/wiki/Greenland