if c02 has risen by 65 ppm in the last 40 years
and to reach 550 we need another 182 at the current rate that adds up to 120 years so 2130 is where it hits, but we are working on mitigation as we speak. Patents are being issued, companies going public in the next 5 years that will be busily sequestering c02 so I think it will take a lot longer to get to 550 than 2130
If we torture the data long enough, it will confess. (Ronald Coase, Nobel Prize for Economic Sciences, 1991)