Wood Romances

We hear a lot that climate models predict too much warming of global mean surface temperature (GMST), but just about every graph intended to back this up contains flaws or misrepresentations, either by sloppy comparisons of models vs observations or using a subset of models that are heavily influenced by those with high sensitivities. I think it's valuable to show how well models form, since the sensitivities of those that perform the best are likely to be good indicators of the sensitivity of the real climate system. So I thought I'd toss my hat in the ring by comparing Hansen's 1988 climate model with observations. This has been done before, most notably by Zeke Hausfather in 2019, but it's been 6 years since then, and I thought it might be good to update it. To do this, I downloaded Hansen's data for GHG forcings and temperatures for his Scenarios A, B and C (available here and here ), and I plotted these scenarios with the major GMST datasets against their 1958...

I frequently see challenges to the US temperature record that claim that many stations are affected by poor station sighting, and that biases introduced by poor station siting may account for a significant fraction of observed warming in the US. The claim is that a significant number of stations located near asphalt or at airports or too close to buildings can cause thermometers to record artificially high temperatures, adding spurious warming trends to CONUS temperature trends. With the USCRN project, NOAA developed a classification system based on exposure characteristics affecting the siting of stations, and this classification system was retroactively applied to the stations in the old USHCN network by Anthony Watts and surfacestations.org. In this classification system, ratings of 1 and 2 indicate "good siting" and ratings of 3, 4, and 5 indicate "poor siting." These classifications can actually be used to test whether station siting has any impact on CONUS tem...

I frequently hear people downplay the claim that the 1.3°C warming above the 1850-1900 mean is geologically significant. I hear words like "slight" or "modest" or "insignificant" thrown around a lot. And certainly global temperatures have increased by a lot more than 1.3°C on geologic time scales. My first response is typically to point out that on geologic time scales, global temperatures do change a lot, but at much slower rates. Current warming rates are exceptional, even on geologic time scales. And I think this point can be relatively easily demonstrated with the evidence we have, even taking into consideration the fact that proxies do not preserve a high degree of temporal resolution, and actual warming rates may exceed what we can detect with proxy evidence. I think we need a two part response to this. Defining Geologically "Rapid" Warming Since terms like "rapid" are relative terms, I think we need to come up with a standard for...

A paper was published this week that argues that low-sensitivity models do a poor job of reproducing CERES-derived EEI trends. In the words of the paper, the authors used CMIP6 models "to illustrate that low climate sensitivity models have an EEI trend behavior that is inconsistent with the satellite-derived EEI trend." Even though models with an ECS near 3°C do a good job of reproducing current warming, CMIP6 models often differ in the in EEI trends. For instance, The CERES data show a stronger trend in EEI than the multi-model CMIP6 mean and higher EEI in 2023 than any of the CMIP6 models. However, for individual CMIP6 models and ensembles, EEI is comparable to or higher at other periods than the CERES value in 2023. The difference in trends can be seen by comparing the red CERES line to the black CMIP6 model mean. Even though the interannual variability in the CMIP6 models is consistent CERES observations, the observed trend in EEI, especially since about 2010, is higher t...

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...

A new paper[1] by Spencer and Christy was published on urban heat islands (UHI), and I'd like to clarify what it says and what can actually be claimed as a result of it. The reason why has to do with a recent blog post from WUWT that claims the paper shows that 65% of global warming is due to UHI warming effects, rather than increasing greenhouse gas concentrations. Chris Rotter at WUWT says, A new study from the University of Alabama in Huntsville addresses the question of how much the Urban Heat Island (UHI) effect is responsible for the higher temperatures at weather stations across the world. Dr. Roy Spencer and Dr. John Christy have spent several years developing a novel method that quantifies, for the first time, the average UHI warming effects related to population density. Their finding: no less than 65% of “runaway global warming” is not caused by our emissions of carbon dioxide, but by the urbanization of the world. There's very little in this that resembles what the...

If you follow popular discussions about AGW, you'll likely see many claims that climate scientists have been making terrible predictions and climate models invariably run too hot compared to observations. If you investigate these, almost all of so-called "predictions" of climate scientists turn out to be some combination of misinformed assessments by media personalities, reporters and politicians or claims by scientists that have been misread by contrarians. And while it's true that some climate scientists have said some things that have not panned out, this is clearly the exception, not the rule. In fact, overall, climate scientists have been slightly conservative with their predictions, and climate model have performed quite well.[1] In fact, Zeke Hausfather has done a pretty good job of tracking how model predictions compare to observations, and overall, they've done quite well. So given all the rancor from contrarians about the predictions of climate scientist...