>- Nuclear Weapons
The several non-nuclear proliferation treaties and disarmament talks that have reduced the number of warheads down by about 2/3? Just because there may be more "threat actors" doesn't mean that we're not safer. Look at South Africa, it was a nuclear power and gave it back.
>- Genetic Engineering
There are many laws in place. Some that are even hampering valid benefit (Umbilical Stem Cells). Some that are straight up asinine (Abortion Bans legal again) and some that should be observed but allowed (Crisper) as what we knew even 30 years ago is magnitudes more than the previous 30 to that. What will we learn 30 years from now?
>- Chemical production and pollution
When was the last time the Ohio river caught literal fire? It's been a while. My whole lifetime. But it did at one time. That one case was a tipping point for the formation of the EPA. The plastic island in the Pacific? It's being cleaned as we speak. Will we be zero pollutants in our life time - probably not, but the same could be said about racism or wealth inequality which is much easier to education and manipulate in contrast.
>- AI
Again, much easier to legislate and manipulate. The biggest problem: public understanding of how it's made and capable of to an uneducated population. Where it can go wrong? The profit motive. Where it can save us? It's already happening today in medical diagnostics.
>- Social Media
Same deal here... legislate and manipulate. The biggest problem is engineers and lawyers actively pursuing ways to game the system once sold to business people. It's already benefitted us to help provide places to discuss and connect in ways that were never possible without resorting to being held by a geographic or cultural chain.
>- Nanotechnology
See the other answers. However when the robots do a better job of co-habitation and evolution than humans, better be ready to swallow one's pride as they hit singularity before us.