6dc5455c____The_Coppermind___17th_Shard__Entry
[Chapter] 4 [Entry] 
This is actually what happened to Rashek, I believe. He pushed too hard. He tried to burn away the mists by moving the planet closer to the sun, but he moved it too far, making the world far too hot for the people who inhabited it. The ashmounts were his solution to this. He had learned that shoving a planet around required too much precision, so instead he caused the mountains to erupt, spewing ash and smoke into the air. The thicker atmosphere made the world cooler, and turned the sun red.
The Hero of Ages/Epigraphs - The Coppermind - 17th Shard
Entry