As the physical environment is composed of the natural vegetation, reliefs and the land water and the air, etc.
The countries that need to changes their physical environment are Canada, the united states and the Mexico as they are reasonable for the global population migration and except that of the Greenland.
As the continent is filled with ice and has little of the land for the agricultural purposes thus very few or sparse population inhabits the lands. Also, the majority of the landscape is already melting due to the impacts of the climate change.
