Home/BlogThis is just a short update regarding how global surface air temperature (Tsfc) trends are tracking 34 CMIP6 climate models through 2025. The following plot shows the Tsfc trends, 1979-2025, ranked from the warmest to the coolest.
“Observations” is an average of 4 datasets: HadCRUT5, NOAAGlobalTemp Version 6 (now featuring AI, of course), ERA5 (a reanalysis dataset), and the Berkeley 1×1 deg. dataset, which produces a trend identical to HadCRUT5 (+0.205 C/decade).
I consider reanalyses to be in the class of “observations” since they are constrained to match, in some average sense, the measurements made from the surface, weather balloons, global commercial aircraft, satellites, and the kitchen sink.
The observations moved up one place in the rankings since the last time I made one of these plots, mainly due to an anomalously warm 2024.
In your view, do CMIP6 models represent a significant improvement over CMIP5 when compared with observations?
No model that uses GHG radiative forcing is a significant improvement.
Indeed!
Sure..basic atmospheric physics must be wrong!
How did you select these 34 CMIP6 climate models? Are they using the same GHG concentrations history that we had?
Another comparison:
https://www.realclimate.org/index.php/climate-model-projections-compared-to-observations/
Are you saying that Roy is wrong?
The RealClimate link undoubtedly provides a more comprehensive perspective of climate model vs observation comparison. But one doesn’t have to chose one or the other, understanding “both” perspectives is always an option.
In science we are skeptical and can be critical of anyone’s analysis.
i am skeptical of YOUR science.
“RLH says: i am skeptical of YOUR science.”
One of the hallmarks of intellectual honesty is to apply the same rigorous standards to one’s own beliefs as one does to others’ claims.
This is where most self-identified skeptics go wrong.
To be fair, introspection is very difficult.
Nate
” In science we are skeptical and can be critical of anyone’s analysis. ”
True!
But… regardless of how true that is, for people like ‘RLH’ it only applies if data processing and/or analysis shows signs of cooling.
That’s the reason why I call him ‘Blindsley H00d’: he keeps since ever blind on the same eye.
According to Berkeley Earth, NOAA has not been able to report a massive number of stations from around the world since August, 2025. As a non-scientist and just an interested person in these matters, I continue to be amazed at the poor quality of our current data (inferior siting of stations in the U.S. for example.) The developed nations have been spending massive amounts of money on CO2 abatement, research, etc and we can’t produce reliable temperature data? Apparently, the NOAA issue is a botched computer conversion (I think software). If NOAA doesn’t care enough to treat that as a high priority, why should I care about warming?
Then there is the older temperature data going back to, say, 1875 and forward. John Christy wrote a book entitled “Is It Getting Hotter in Fresno…Or Not? His research makes it clear that the older temperature records, at least in Fresno, are quite dicey.
Then there is the land temperature record outside the USA since 1875. Vast areas that are underpopulated, subsistence societies, industrialized nations ravaged by two world wars, many colonies of western advanced that lost that expertise (technology and interest in science) when colonialism ended.
No, I really am coming to the conclusion that our “vision” of temperature trends is quite limited. I am quite skeptical that scientists can take sparse and often bad data and somehow magically produce something that approximates reality. I do trust the satellite data, but that takes us back only to 1979.
And that is 29% of the earth’s surface.
“Apparently, the NOAA issue is a botched computer conversion (I think software).”
Evidence?
You are very tedious, sir. I didn’t make that up. I dug in a little and tried to find out the cause. Use AI for a little and you’ll get more background on it. Berkeley Earth is reporting about it. They use some other data sources, but they show a map of NOAA’s global reporting network sites and large parts of the globe (outside US) are dark (if it still is uncorrected).
The article that I have linked below has a first section that has some very insightful and wise observations about data and its use. Even though its author is a finance professor who focuses on investment valuations and decisions, the first section applies to anyone trying to use data in a sophisticated way. I see many applications of his observations to climate science. Just ignore the rest of his blog post after the opening section on data. The author -Dasmodaran- is quite experienced and respected in his field:
https://aswathdamodaran.blogspot.com/2026/01/data-update-1-for-2026-push-and-pull-of.html