This is a claim about the future which the science does not support, and you seem to be basing a lot of your worldview on it. Have some humility about predicting the future.
> Obviously nobody can know for sure, maybe we will get lucky and someone will come up with a genius plan that actually works.
Nobody can know at all. We're talking about predicting the future.
But it's not really a matter of luck. Humans are problem solvers, now with immense power, capable of doing amazing things when we decide to.
There is scientific consensus that +5C is a doomsday scenario. Civilization ending. This isn't my prediction, this is the scientific consensus. And obviously it's not like +3C or +4C is a walk in the park either. We will be close to +5C within this century unless something changes drastically.
That's not a prediction that's a projection, just like if you're driving your car at 100 miles per hour then in an hour you will be 100 miles ahead. The difference is when it comes to greenhouse gas emissions we do not have a brake pedal and there is no friction. We can't take back the carbon. The only thing we can do, and the only thing we are doing, is accelerate. And on top of that, we're going downhill - we're accelerating whether we want to or not. And it's getting steeper the further we go.
Ice reflects an enormous amount of energy back into space, as the amount of ice drops the amount of heat absorbed by the planet increases. On top of that, the ice traps enormous amounts of greenhouse gases. In the poles and previously permafrozen tundras that are now thawing. As the atmosphere heats up it is capable of holding more water vapor which is also a greenhouse gas. Warmer temperatures also lead to forest fires, releasing huge amounts of greenhouse gases and weakening one of the few ways we're actually removing some carbon from the air.
These are some of the feedback loops in play causing warming to rise exponentially the worse it gets.
> Nobody can know at all. We're talking about predicting the future.
Scientists predicted the future 50 years ago and we are right on track for those predictions. 50 years ago they said this is where we will be in 50 years, and here we are. Now you're like "but we can't predict the future" well we did. And to top if off you're waxing about how powerful we are - apparently not powerful enough to predict global warming, but powerful enough to stop it? When? Why aren't we doing it then if we're so powerful? Why are we just making it worse instead?