Kidou Senshi Gundam Eight

Earth: the third planet of the solar system, and the cradle of humanity. As time marched on from humanity's birth, breakthroughs in science and biotechnology promised to end suffering and conflict, ushering in an age of everlasting prosperity... or so it was believed. Now, the year is Koureki 2030. The Earth, once humanity's sanctuary, teeters on the brink of collapse. Only 258 survivors remain. And with them, a single Gundam. (Source: Kadokawa, translated)