Wood Romances

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...

In another post , I covered some of the many reasons why scientists have concluded that urbanization biases are not responsible for any significant fraction of global warming. In order to avoid too much duplication with that post, I'll only briefly summarize the reasons: Homogenization Corrects Urbanization Bias. While cities are warmer than rural areas, they warm at about the same rate as rural areas. The bias is caused by urbanization. That is, as rural areas become more urban, they will warm at a faster rate than rural and urban areas. This bias is effectively removed by homogenization. Very Rural Stations Warm at Least as Rapidly as All Stations. Wickham et al 2013 compared the most rural land stations globally and compared them to all land stations. The study found that "very rural" stations were warming at least as rapidly as all stations. If urbanization biases were making a significant contribution to global warming, then the most rural stations would warm more sl...

One of the more fun aspects of debunking pseudoscience claims is finding humorous ways to replicate the logical flaws of crank theories. The crank theories of Nikolov and Zeller (NZ) are among my favorites, and I just found what I think is a fun illustration of how their thinking can be so wrong while superficially looking convincing to the unskeptical. Simply stated, NZ took some data points about several rocky planets and moons and performed a curve fit for "Relative ATE" as a function of mean surface atmospheric pressure. It looks like this. Since they got the curve fit to work without including the impact of greenhouse gases (GHGs), their conclusion is that atmospheric composition and concentrations of GHGs are irrelevant to the global mean surface temperature on any rocky planet or moon. They then developed a model that reports to be able to predict the mean surface temperature of any rocky planet or moon with just three data points: TSI, albedo, and mean surface atmosp...