The Freakonomics Team has a (relatively new podcast) starring the economist on the team: Steven Leavitt.
The title is "People I (Mostly) Admire" and a recent one is a conversation with Nathan Mhyrvold.
Besides his career with Microsoft, Mhyrvold also has a Ph.D. in physics and is a partner is a recent company reimagining nuclear power, Terrapower.
Mhyrvold claims during the discussion that the Terrapower reactors could all by themselves displace all carbon generation in the entire world economy.
Unfortunately this isn't all that's required, but would be an excellent first step! You still have to remove the existing excess carbon in the atmosphere, now over 400 ppm ...