Complex sentence: This is an order of magnitude greater than that suggested from measured ocean heat storage changes, which suggests calibration anomalies and as has been stated, the CERES instruments rely on a reference detector whose mirrors were never measured and are therefore not trackable to NIST standards.
Split into simpler sentences: This is an order of magnitude greater than that implied from measured ocean heat storage changes, which suggests calibration anomalies. One possibility is as has been stated, the CERES instruments rely on a reference detector, whose mirrors were never measured and are therefore not trackable to NIST standards.