Aside from the ecological themes, this movie is also about connection and loneliness. As the disaster is dividing people, both in the sense of targeting increasingly smaller groups, forcing them to split, and in the sense of turning them against each other, the protagonists are encountering increasingly more divided groups, until they reach the most socially isolated person. Meanwhile the main protagonist and his girlfriend start off divided and have to find a way to reconnect. And right as they do, the disaster stops. M. Night Shyamalan is a poet impressionist, and there will always be people who laugh at poetry. Because they're so emotionally-repressed, they just can't connect with it.