I live in northern Canada, so, it is already habitable. There are many changes here, some good, some bad.
- less heating fuel needed, making life cheaper
- more things can grow, and farms are starting to appear
- melting permafrost means buildings sink into the muck, and landslides cover the only roads. Around Dawson City, the permafrost is around -2C, which is really warm (it should be at least -8C or so). This means a lot of expense getting buildings shored up every few years.
- new animals, e.g., deer, that carry ticks.
- -40C kills lots of bugs, and if it doesn't get that cold, insects, e.g., the spruce budworm can cause a lot of trouble
Other things are changeable, e.g., the glacier that is now melting into the Pacific watershed, rather than flowing in to the Yukon one, causing lower water levels on the Yukon river. It remains to be seen whether this will be good, or bad, but, it certainly means changes have to be dealt with. Another change is the trees that logging companies have to plant (2 for every 1 that they harvest). Do they plant the same variety of tree that they cut, or, ones that will be growing in 50 years time?
One of the biggest issues is change, and, change usually costs money. Even a positive change can have costs.