I think this chart is faked. They’re all using the same data, just different versions of it (different interpretations of proxy data).
Remember Michael Mann’s “nature trick” where he grafted proxy data onto temperature measurements?
This destroys all confidence that NASA is scientifically competent. They put their reputation on the line with this chart.
And the way it’s worded has the nasty feline touch of the progressive Democrat.
So its all political science from now on from NASA.
I think you mean the "hockey stick" in which Mann used fake data.