That does look impressive and scary but I wouldn't rule out:
- Increased volcanic activity or other natural events (e.g. solar activity) causing this spike in CO2.
- Flaws in instruments used to accurately measure CO2 levels in the past due to some variables which have not been accounted for.
- That it could just be a temporary spike which will be offset by global greening, increases in ocean phytoplankton or some other natural events over the next few centuries.
- Increased volcanic activity or other natural events (e.g. solar activity) causing this spike in CO2.
- Flaws in instruments used to accurately measure CO2 levels in the past due to some variables which have not been accounted for.
- That it could just be a temporary spike which will be offset by global greening, increases in ocean phytoplankton or some other natural events over the next few centuries.