Wood Romances

You'll frequently see contrarian influencers on social media showing the differences between "raw" and "adjusted" temperatures for the United States that indicate that CONUS warming in the "adjusted" temperatures is greater than in the "raw" data. We're often told this indicates that scientists have adjusted CONUS temperatures to make them cooler in the past, thus making the amount of warming that has occurred in the US larger in the "adjusted" temperature data than in the "raw" data. It's then frequently just assumed that this is because "liberal" scientists need are conspiring with nefarious intent to tamper with and manipulate temperature data to create artificial warming trends in US temperatures. In another post I share some dishonest way in which contrarians exaggerate the difference between the "raw" and adjusted temperatures, but even in properly plotted comparisons, the final "adju...

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...

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...

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...

NOAA has released their December 2024 results for both nClimDiv and USCRN US temperatures, and 2024 turned out to be the warmest year for CONUS on record (records beginning in 1895). NOAA's website reports CONUS for 2024 as 55.51°F. Below I show several graphs for nClimDiv, with monthly temperatures, a 12-month running mean, and a 10-year running mean. ERA5 for CONUS is also out, and to make apples to apples comparisons, I changed nClimDiv to Celsius and set it to a 1951-2000 baseline. USCRN began recording CONUS temperatures in 2005, so the end of 2024 marks the 20th year for that dataset. Below I show graphs comparing USCRN to both nClimDiv and UAH-TLT for CONUS. Here's how USCRN compares to ERA5, with the scale switched to Celsius to match ERA5. Since USCRN only goes back to 2005, I can't give you 30-year trends, but CONUS is warming so rapidly, that the last 20 years is already statistically significant. From Jan 2005 to Dec 2024, CONUS trends were: USCRN: 0.451 ± 0.241...