Physics used in the service of war/terrorism
Biology used in the service of war/terrorism
Rent seeking of the elite
1. Stupid people
2. Greed
3. Tolerating corruption
1. racism/xenophobia/sexism 2. societal externality costs for industry (like global warming) 3. social media
1. Climate change
2. Nuclear war
I can't think of a credible third.
There is only one: the imbalance of wealth distribution.
1. Greed
2. Climate change
3. Giving power to stupid people
Overpopulation
Misinformation for one of them. Previous US elections, and now COVID, have highlighted how misinformation is both extremely potent/viral, and literally deadly.
1. Entropy (time taking its toll) in terms of corruption at every possible level of material, culture, liberty, biology, political.
2. Inter-generational discounting (you can't make the next generation care about what you cared about) driving a lack of upkeep for essential yet invisible infrastructure.
3. Threats from space: Coronal mass ejection, cometary impact, meteor impact.
IMHO neither AI nor Global warming are as much a threat to human civilization. They could really suck, but they're not going to send us back to the bronze age or extinct us. We're pretty damn clever and resilient.