The Intervention Of Unknown Guests

After a long journey, finally there's a signs of life the young man has witnessed. Humans are extinct and living things like plants and animals no longer exist. The radiation from the sun hits the earth with a high temperature. And the magnetic field that protects the earth from solar radiation , solar winds, and particles have been completely destroyed making the earth inhabitable by living things and by humans.

Year was 8120 and humans are gathered living in a remote tower. Radiation struck the earth's surface and probably 8150 will be the end of earth's existence.

Plot twist: Unidentified race has destroyed magnetic field ... the van allen belt, making the earth exposed from solar winds and cosmic rays.

@gremayo