This is incorrect. Accelerated weathering of olivine can do the job, even powered by diesel and coal, for about trillion in capital costs and a trillion a year

This is incorrect. Accelerated weathering of olivine can do the job, even powered by diesel and coal, for about trillion in capital costs and a trillion a year in running costs. That's one percent of world GDP. All the technologies involved are standard rock mining and pulverizing stuff that has been in use for many decades. The downside, of course, is blanketing parts of shallow seas with rock flour.