That’s an indication of the personal bias of co-author Schmidt, who in the past has repeatedly maligned the UAH dataset and its authors because their findings didn’t agree with his own GISTEMP dataset.
In fact, Schmidt’s bias was so strong that when invited to appear on national television to discuss warming trends, in a fit of spite, he refused to appear at the same time as the co-author of the UAH dataset, Dr. Roy Spencer.
A breakdown of several climate datasets, appearing below in degrees centigrade per decade, indicates there are significant discrepancies in estimated climate trends:
AIRS: +0.24 (from the 2019 Susskind et al. study)
GISTEMP: +0.22
ECMWF: +0.20
RSS LT: +0.20
Cowtan & Way: +0.19
UAH LT: +0.18
HadCRUT4: +0.17
Which climate dataset is the right one? Interestingly, the HadCRUT4 dataset, which is managed by a team in the United Kingdom, uses most of the same data GISTEMP uses from the National Oceanic and Atmospheric Administration’s Global Historical Climate Network.
A careful look at the early 20th century global warming, which is almost as large as the warming since 1950. Until we can explain the early 20th century warming, I have little confidence IPCC and NCA4 attribution statements regarding the cause of the recent warming.
This is an issue that has long interested me. Peter Webster wrote a previous post Mid 20th Century Global(?) Warming, which focused on the warm bump that culminated in the 1940’s. My interest in this period was reignited while working on my report Sea Level and Climate Change. Then, the recent paper by Zanna et al. discussed in Ocean Heat Content Surprises further made the wheels turn.
In response to the Ocean Heat Content thread, David Appell posted a link to this paper on twitter: