Wood Romances

The graph below from John Shewchuk is intended to show that models predict too much warming compared to satellite data. Shewchuk claims that the red line is the average of 102 IPCC CMIP5 model runs for the surface through 50K feet. In all likelihood, this is just lifted from graphs of model-observation comparisons that John Christy has plotted in the past. Shewchuk claims the blue line is UAH satellite observations for the total troposphere layer (TTT). The problems with this graph are numerous, and many of the problems are inherited from Christy's graph (problems with his comparison are well-documented ). The two time series are separated from each other even in 1980 to exaggerate the differences between the two (even if the trendlines do intersect at 1980). The 102 model runs are not shown, only the model mean, and the 95% confidence interval is also not shown, so we have no idea what the spread in the model runs might be. But Shewchuk has added his own dishonest twist to this g...

There's a  schematic  that is frequently promoted by John Shewchuk on X to claim thatt long-term solar cycles explain much more of temperature variability of the last 2000 years than changes in greenhouse gases like CO2. The implication is also frequently made that the current warming over the last century or so is due to these cycles and not to changes in GHG concentrations. One common version of this graph is here. The Hallstatt-Bray cycle, which has a periodicity of ~2400 years, and the Eddy cycle, which has a periodicity of 976 years, are both related to sunspots, and so they indeed do have an impact on total solar irradiance (TSI), and therefore they can in principle have an effect on global temperatures on millennial timescales. But the significant question is, by how much?  Astute observers will note that Shewchuk didn't include any scale for the y-axis; the impact of these cycles could be negligible or large as far as this schematic is concerned. I do find ironic,...

If you follow climate discussions on X, you're bound to see John Shewchuk and/or Tony Heller show graphs that reportedly show that NOAA is tampering with temperature data to fabricate global warming with spurious warming trends. I've gone over many of the reasons why this is nonsense before in posts about bias correction and so-called  ghost stations . I think it's good to show what's actually going on with the graphs they present as "proof" of data manipulation, though. I think it can be easily demonstrated here that it's actually Shewchuk and Heller that are tampering with data. Shewchuk (Top) and Correct (Below) Above are two graphs. The top graph shows what John Shewchuk claims shows that NOAA is manipulating data. It shows USHCN "raw" and "altered" Tmax data for 1900 to 2023. The bottom graph above is the correct plot of NOAA's published data from the current and correct dataset (nClimDiv) with a 5-year running mean to match S...