Its own advocates admitted it would have a $100 trillion dollar price tag and slow the rate of warming by perhaps a fraction of one percent.

Looooooool...

One correction, this isn't true. Plants turn CO2 and water into oxygen and sugar. Plus, "carbon fixation" is a process where CO2 get sequestered in the earth or in something on the earth.

No of course, but I'm referring to the generally accepted statement that the atmosphere would need around 1000 years to fully reset if we returned to the Stone Age tomorrow. In that context any added carbon is effectively permanent.