In some of those in green, I think the meaning is literal, not idiomatic. With the Arctic, there are local issues, such as the impact on the Inuit, animals, and the region in general, but a meltdown there has global implications. With the example of America, I think it's literal again, as a unilaterlaist approach does automatically set that state in contrast with the rest of the world; maybe not every single state, but it does stand apart.
With the example of the recruitment of students, then it is an idiomatic usage, implying everyone else around those recruited.
With the examples in blue, I think the title one with Al Gore, could e idiomatic- separating Mr Gore from everyone else. the others seem fairly literal to me- the planet can be voiwed from different angles- different states, different species, etc.
- For Teachers