If we really take climate science to its conclusion, there might be some good places to pick up cheap land now. Most places are expected to see a detrimental effect from climate change, but there are a few exceptions.
The Uninhabitable Earth says: "The breakdown by country is perhaps even more alarming. There are places that benefit, in the north, where warmer temperatures can improve agriculture and economic productivity: Canada, Russia, Scandinavia, Greenland."
Turns out you can't really own land in Greenland - http://archive.ph/DHIuC
Norway, Finland, Sweden, Iceland, Denmark, Scotland, Russia, Chile, Argentina all allow foreign freeholds - http://www.financialfreedomindex.com/freehold_property.php
Rising sea levels threaten a lot of Denmark.
Some info on Chile's real estate market: https://www.globalpropertyguide.com/Latin-America/Chile/Price-History
Argentina: there are ridiculously large patches of land available in the country's interior. e.g. This is 5133 hectares for $450 per hectare: http://ranchinvestments.com/default.asp?f=listing_details&listingid=461349
http://floodmap.net/ lets you know where'll be underwater after a given sea level rise. Set it to a 6m rise and you're probably safe; 10m to be ridiculously conservative.
Iceland is another one to look at.