The fact that Canada is not on the list with 90% of its territory hosting no humans while many more densely populated African countries make it is very indicative of the different impact they have
Central African Republic is not here, for real? As far as I remember, CAR is almost totally dark in Africa night images. Found it funny that even Guinea Bissau appears, but CAR don't.
It just misses out at 0.049. Actually there are clearly some strange things going on with this source, but I couldn't find anything better (for example, Bouvet Island, with a population of 0, supposedly has more light pollution than Tanzania, with 58 million)
It doesn't specify human-made brightness. A small island probably has a lot of brightness due to surrounding water reflecting starlight and moonlight, compared to a heavily forested country that absorbs starlight and moonlight. Just a guess.
It's hard to believe that countries comprising lots of far-flung islands shouldn't be at the top of this list. If one was to incorporate their national waters (not EEZ territory, just commonly recognized non-international waters), they would become the most sparsely-populated countries. And, aside from lights on ships, that territory would generate no artificial light. Kiribati, the Marshall Islands, Micronesia, Tuvalu, the Maldives, and the Seychelles were among my first guesses. Must be a methodology issue.
The source calculates brightness per land area. If you look at the atolls of those island countries, you see that they're not exactly sparsely populated - take Male in the Maldives as an example. If you include water area it heavily biases results towards countries with a little land and a lot of water because that water as you said cannot produce light and nobody lives there, so it has no purpose for the quiz and makes no sense to include it. The Solomon Islands do make it because they are relatively large, forested islands with relatively small populations (which as we have seen is not entirely the determining factor, but it helps). Tuvalu, e.g. does not make it because it has very little *land* area.
Tricky-ish. I just got all the African countries and DPRK. I did try a few Oceanian countries, but after none of them hit I decided they were probably all off limits.
The "Rad/1K pop" column in the source really tells the story here.
https://www.lightpollutionmap.info/
The oil fields of North Dakota are more of a bright spot on this map than the Minneapolis metro region.
Also, the North Slope of Alaska is another clear example.
Lastly, the largest white spot in South America is in the Venezuelan oil fields.
The other two were both total surprises for me.