What should a person do to save life on earth?

To preserve life and its diversity on the planet, a person must prevent, first of all, the proliferation of weapons of mass destruction. In the 60s of the 20th century, it already happened that several countries accumulated so many weapons of mass destruction that they could more than once destroy all life on the planet. Also, a person should not allow the release of radioactive and chemical substances, since they can cause great damage to living organisms. Limiting the emissions of various gases that degrade the ozone layer also protects life.