The climate change discussion gets bogged down in the hypothetical and abstract so often.
ITT you are the dictator of the world, which means all political impediment to your desired solutions are moot. You can literally do anything but you are also responsible for all externalities.
Explain your idea, but also anticipate the externalities and how you might mitigate those.
Mine would be the creation of a global research agency with two main focusses; carbon capture and green energy.
This would be incredibly expensive but I would mitigate costs by diverting all of the worlds weapons research into this task. The people who work in weapons research would be retrained to work for this agency.
Put in a 200 dollar a ton carbon tax which is immediately distributed as UBI that phases in over 5 years. Pay 40 dollars a ton for captured carbon (only payable on wood delivered to our carbon sequestration landfills).
Pump 100B a year into research on nuclear power and when the safety/disposal issues are resolved subsidize costs by 50% for 15 years on new construction/implementation.
Nationalize every company that significantly funded climate denial propaganda and use the proceeds to subsidize green initiatives.
Give Saudi Arabia the same sanctions that North Korea has and watch them return to tents in the desert.
Dissolve national governments and land borders, the biggest obstacles to mitigating climate change, creating (where they don’t exist) local government.
Raise money by taxing the fuck out of areas with large GDPs and Amazon, Google, Facebook etc.
Use it to fund research centres in the US, Europe and Asia, attracting top scientists in related fields and also investment in education and health programmes in Africa and other impoverished areas. Embezzlement by local leaders will be met with harsh sentences - no way am I creating millionaires/billionaires there.
Seize and decommission all nuclear and chemical weapons and ban development of any more.
I would probably golf a lot, grab everybody by the pussy, and eat a lot of Big Macs. Then plan the rest of my strategy based on whatever the opposite of what Obama would do is.