Songfacts®:

• "Catastrophist" deals with the theme of humanity being led down the path of self-destruction by their leaders. It is one of the first tracks bassist Paolo Gregoletto wrote for What the Dead Men Say; he explained to Apple Music that he "was just piling up riffs for this song and it seemed to get longer and more complex."
• Gregoletto recognized that the words needed to fit in with the song's epic feel. He was reading at the time David Wallace-Wells book about the consequences of global warming The Uninhabitable Earth and Naomi Klein's work about the disaster capitalism The Shock Doctrine. He explained that he wrote the lyrics "thinking about these crises that happen in the world and how some people can benefit from them but a lot of people have to suffer and pick up the pieces or are left to their own devices. And what you do in the world kind of determines what people who aren't even born yet are going to have to deal with."
• When vocalist Matt Heafy first heard Gregoletto's song idea, it reminded him of Swedish melodic death metal music such as early Amon Amarth, so he brought in a guitar melody that was a Gothenburg-style melodic death metal along the lines of At The Gates. He explained to Music Radar:
  
  "The harmony of that high Swedish melody is all major – it's so bizarre and happy-sounding when you hear it alone. It constantly changes key, modes and feel but it all makes sense and works. I think it's a nod to the Shogun era of Trivium where we had a little bit of everything on each song."