> As far as nuclear bombs, we don't really seem to be using them much anymore.

On the contrary, I think 'we' (the US) use them every day as leverage and a deterrent. We just don't need to detonate them anymore. I think there is more to it than them being just a trump card. You only get to use a trump card once.

Our conventional weapons and economic influence are the leverage and deterrents. It's pretty unlikely that we would ever again nuke a non-nuclear entity. The non nuclear entities know this, so nukes don't really provide any leverage over them. It's our drones, ships, etc. that do, at least on the military side.

For the few entities with nuclear weapons, it's MAD. We would only play the card once, since it would be the final round of the game with that entity.

Any technical solutions to the global issues we face will be thwarted by sociological factors due to our immaturity as a species. Climate, for example, requires cooperation on a global level and all populous industrialised countries must participate. China, for example, may decide to not participate for any number of economic or political reasons. What then? They would be further destroying the planet. Should we force them to participate since their decision is adversely affecting other nations?

Solutions don't necessarily need everybody to be on board.

Somebody could come up with something tomorrow. Maybe a bacteria that can populate the ocean, which precipitates carbon from CO2 in the air, and drops little pellets to the bottom. Probably not a real practical solution, or even a good idea, but it shows how things could rapidly change if the right tech comes along. They wouldn't need to get everyone together - just a petri dish thrown into the ocean.

We are still thinking of solving today's problems with today's technology, which I agree is futile to get everyone on the same page.

Certainly possible. Problem is that the issues are very diverse. You have increased carbon, over-population, resource depletion, increased toxins in environment, etc, and each would require very different technological solutions. Also, I think solutions such as your bacteria idea would just make us lazy. We wouldn't fix the real issue but would just ultimately rely on technology to solve what are really social issues.