Singular matter's grim world

World of the singular matter is post-apocalyptic, uninviting, and grim place to live. This is caused by multiple factors. The greatest problem was the eruption of Yellowstone volcano in USA. Though it was not so devastating as scientists predicted, it caused a lot of deaths, and the death toll is climbing. Many places in California are now unhabitable. This caused a lot of dwellers to move to the east coast or leave the country for good.
It disrupted weather patterns around the globe, making some places freezing cold and other extremely hot.
Melting permafrost caps of Antarctica are releasing substantial amounts of ammonia, which also further speeds global warming.