Level One Dreamers

I have a theory that Yoko is the cause of the asteroid that slammed into Earth and caused the Ice Age. "Wait what? How can that be possible?"
When Yoko sabotaged the Colony Ships, one of them flew around the sun and vanished. In Star Trek IV, Kirk and Co. flew around the Earth's sun to go back in time by going fast enough.(The Slingshot Maneuver)  What people believed was an asteroid was the colony ship that went back in time. Out of control it slammed into Earth causing the Ice Age and the future events of the series.