Existential Risks in the Solar System

There are strong reasons to believe that the survival of life on the Earth is under threat. Human activity is one example that we are able to control, at least in principle. We might irreversibly pollute, or destroy the planet with thermonuclear devices. Epidemics might become uncontrollable. 

Asteroid impact could devastate the Earth, although preventive measures might detect and monitor orbits of potential killer asteroids. Longer term, the sun will evolve into a red giant and expand to a hundred times the orbit of the earth. The earth will burn to a crisp, losing its atmosphere and oceans. By then, humanity, or whatever remains, should have found safer havens than the inner solar system.