Based on the easily proven temperature dependency of the OLR, there is no reason to believe that the difference is
satellite calibration error (although that doesn't mean there is none).
It also doesn't exhibit variation
of calibration error with age, but such variation shouldn't have a significant impact unless, over the range where the likelihood function for the sample is significant, it is substantial in relation to 14C determination error.
What's less - well known is that satellite data require analagous procedures to account for orbital decay, instrument degradation over time, and
possible calibration errors.
Even if true, about
1oC calibration errors (I don't believe you, BTW), if you take many hundreds of thousands of measurements each with an error range of 1, the resulting certainty of your aerage is much much less than one.
We have obtained reams of documents showing problems with breathalyzers in British Columbia, ranging from
minor calibration errors to catastrophic malfunctions.
Many warmists have noted that the annual change in OLR is smaller than
the calibration error for measurement device (spaced based satellite in this case).
Now it may have been that there was some instrument problem, fault or
calibration error.
(Note that results from both models are affected by
the calibration error discussed in 2.)
I understand that just splining the series is an assumption of zero
calibration error, but at least that's a presumably random error.
This is because
the calibration errors are magnified for predictions based on proxy
The curved blue lines in Figure 9 - 1 present
the calibration error, or the uncertainty in predictions based on the calibration (technically the 95 percent prediction interval, which has probability 0.95 of covering the unknown temperature), which is a standard component of a regression analysis.
One is the variance of the errors in the regression equation, which is estimated from calibration data, and may be modified in the light of differences between
the calibration errors and the validation errors.