Actually it's even easier to do nothing if you throw up your hands and say it won't work anyway.

The earth will warm more than 2°C from "baseline" no matter what. Now the 1 trillion ton additional CO2 is an interesting benchmark, but I would guess staying under it has very little to do with energy consumption, and almost everything to do with advances in carbon-neutral and carbon-negative power generation technologies to be invented and scaled over the next century.

But not generating the power in the first place just isn't a choice. If it's a hard-line ultimatum I think a billion people could die trying to fight/enforce it.

The takeaway from OP is that climate changes. It changes quite dramatically. And it changes with or without humans in the mix. Maybe we need to spend that $100 trillion getting more adaptable to changing climate rather than entertaining some fantasy that we can control Mother Nature within some sliver of a temperature range relative to her broad historical performance.