The 4 biggest threats by us to the unrecoverable complete destruction of humanity

The 4 biggest threats by us to the unrecoverable complete destruction of humanity if we stay silent, silence like a cancer grows   

1 nuclear bombs lead to a nuclear winter where sun will be blocked for years causing the crops that humanity depends on to fail

2 climate change could result in a lot of terrible extinction scenarios or unrecoverable collapse of human civilization that we should be working hard to prevent

3 technology and research such as engineered pandemic, biotechnology, create deadly germs, bio-warfare, research accidents, genome sequence modification, availability of dangerous information, research publication about genomes of deadly viruses, create pathogens  

4 artificial intelligence (AI) such as we place our future in the hands of the AI systems we create, scientists are finding extremely difficult to create AI that is perfectly aligned with human values

The risk is from human action and it’s within human control.
If we safeguard humanity's future as the defining issue of our time, we can reduce this risk.
It is in our hands.