Rogue Star: Frozen Earth by Jasper T. Scott

A DEAD STAR IS HEADED FOR EARTH…
THE SHIFT IN EARTH’S ORBIT WILL UNLEASH A NEW ICE AGE…
AND THIS SUMMER WILL BE OUR LAST.
Logan Willis’s life is falling apart: he lost his job and found out that his wife is cheating on him all in the same day. Thinking that his world has ended, Logan checks into a hotel and turns on the TV to see that he’s not far wrong—radio telescopes have detected something big and cold moving toward us at over 500 miles per second.

Still reeling from the news, Logan gets a phone call from his brother-in-law. Richard is talking crazy about the end of the world again, but this time he doesn’t sound so crazy.

The nations of Earth prepare to fight over all of the warmest parts of the planet. But as war fleets set sail and armies begin marching south a stunning discovery is made that will change a lot more than just the weather.