Large parts of India and China, the two most populous nations in the world, are likely to be rendered uninhabitable by climate change.
Large parts of China are currently uninhabitable, for a given value of 'uninhabitable'.
https://en.wikipedia.org/wiki/Gobi_Desert
India is unlikely to become
uninhabitable, but routine failure of the monsoon rains could easily slash the agricultural capacity of the sub-continent, making it unviable to support a largely agrarian economy of over a billion people.
Of course, a large part of North America is uninhabitable too; People either don't live there at all, or live by the gift of extensive infrastructure and efficient transport of goods and people, while using communications systems to link their communities to more habitable regions. Las Vegas has no redeeming features in terms of habitability of climate. It exists only because people choose to dump huge sums of money there, and with enough money, humans can live almost anywhere.