I actually care a lot about whether we should care about climate change, but not right now. Right now, I want to see the places people moved from linked to the places they moved to. The fact that people are moving to Florida is meaningless to me if I don’t know where they’re moving from.
There are 3,144 “county equivalents” (from Wikipedia) . That means the complete undirected graph has 3144(3143)/2 = 4,940,796 possible edges. I’m not sure how this is changes for a directed graph in which each edge appears exactly twice (once in each direction).